Caecal decompression in the horse · My first recollections of caecal decompression from the Large Animal Teaching hospital was a sentence from an American professor in internal medicine

F A C U L T Y O F H E A L T H A N D M E D I C A L S C I E N C E S U N I V E R S I T Y O F C O P E N H A G E N

Master’s thesis Ylva Winsborg

Caecal decompression in the horse Effects and complications

Academic advisor: Tina Holberg Pihl

Co-advisor: Susanne Nautrup Olsen

Submitted: 01/02/14

Author: Ylva Lovisa Margareta Winsborg swg905 Written at: Medicine and Surgery

Department of Large Animal Sciences

Faculty of Health and Medical Sciences

University of Copenhagen

Denmark 2014 Title: Caecal decompression in the horse Effects and complications Title (Danish) : Trokarisering af caecum hos hest Effekter og bivirkninger Key words: Caecum, caecal, horse, trocarisation, decompression, treatment, colic, outcome, effect, complications. Academic advisor: Tina Holberg Pihl, DVM, PhD, Medicine and Surgery, Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Co-supervisors: Susanne Nautrup Olsen, DVM, PhD, Dip.ECEIM, Head of Large Animal

Teaching Hospital, Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.

ECTS: 30 Submitted: 01. February 2014 Signature: _______________________________ Ylva Winsborg

ContentsPREFACE ............................................................................................................................ 5

ACKNOWLEDGEMENTS ................................................................................................... 6

LIST OF ABBREVIATIONS ................................................................................................ 7

LIST OF DEFINITIONS ....................................................................................................... 8

ABSTRACT ......................................................................................................................... 9

RESUMÉ ........................................................................................................................... 10

INTRODUCTION ............................................................................................................... 11

BACKGROUND ................................................................................................................ 13

Caecal tympany and use of caecal decompression ....................................................................................................... 13

History ............................................................................................................................................................................. 14

Risks in relation to caecal decompression..................................................................................................................... 15

Caecal anatomy ............................................................................................................................................................... 16

Etiology of caecal tympany ............................................................................................................................................ 17

Physiology of caecal tympany ........................................................................................................................................ 17

Indications for percutaneously caecal decompression ................................................................................................. 18

Methods for percutaneous caecal decompression ........................................................................................................ 19

Caecal decompression procedure at the Large Animal Teaching Hospital (LATH) ................................................ 20

Transrectal decompression of the caecum .................................................................................................................... 22

OBJECTIVES .................................................................................................................... 24

HYPOTHESES .................................................................................................................. 26

Pain reduction ................................................................................................................................................................. 26

Change of clinical signs .................................................................................................................................................. 27

Complications due to repeated caecal decompression ................................................................................................. 28

Medical and Surgical colic ............................................................................................................................................. 29

Respiratory changes ....................................................................................................................................................... 29

METHODS AND MATERIALS .......................................................................................... 31

Statistics ........................................................................................................................................................................... 35

RESULTS .......................................................................................................................... 36

Case material ................................................................................................................................................................... 36

Treatment and outcome ................................................................................................................................................. 39

Complications .................................................................................................................................................................. 41

Questionnaire .................................................................................................................................................................. 42

Pain reduction after caecal decompression .................................................................................................................. 43

Change of clinical signs after caecal decompression .................................................................................................... 47

Complications due to caecal decompression ................................................................................................................. 50

Medical and Surgical colic ............................................................................................................................................. 51

Respiratory changes ....................................................................................................................................................... 52

DISCUSSION .................................................................................................................... 53

Indications for caecal decompression ............................................................................................................................ 53

Effects of caecal decompression ..................................................................................................................................... 55

Complications of caecal decompression ........................................................................................................................ 56

Limits in this study ......................................................................................................................................................... 58

CONCLUSIONS ................................................................................................................ 60

PERSPECTIVES ............................................................................................................... 61

REFERENCES .................................................................................................................. 62

LATH Procedure for Caecal Decompression, 2009 ........................................................................................................I

LATH Procedure for Caecal Decompression, 2006 ...................................................................................................... II

Letter to Owners ............................................................................................................................................................ III

Online Questionnaire ...................................................................................................................................................... IV

Preface The procedure of caecal decompression, also called trocarisation, has a long history. It is said that

the name of the instrument used for this procedure, “The Danish Military Trocar”, derives from its

use by the cavalry. Apparently, every soldier had a trocar in his saddle bag, and was ready to

perform a life saving caecal decompression, should it be necessary. I have not been able to confirm

any of these stories, but I can confirm that caecal decompression has a history spanning at least 200

years.

It has been said, that true genius lies in simplicity, and I can’t help to think that whoever invented

caecal decompression in the 18th century must have been a bit of a genius.

Trocarisation rests on a simple principle - localising the site and cause of pain and evacuating the

cause of it. Considering the lack of antibiotics, aseptic techniques, modern equipment and

analgesics, conducting this procedure in the late 18th century is impressive.

My first recollections of caecal decompression from the Large Animal Teaching hospital was a

sentence from an American professor in internal medicine. I don´t remember it word by word, but

the essence of it was: “Why do these crazy Danes always insist on inserting those rusty trocars into

the caecum of every colic horse?”

Caecal decompression is truly controversial, and that is why I decided to dig deeper into its effects

and complications.

5

Acknowledgements I want to sincerely thank my scientific supervisor, Tina Holberg Pihl, for introducing me to the

subject of my thesis. She has been very helpful and enthusiastic about the project. I am grateful for

all the help, explanations and scientific input I received from her.

I also want to thank my co-supervisor, Susanne Nautrup Olsen. She has been very constructive and

critical in a manner that facilitated my data collection and hypotheses. In addition to this, she has

assisted me greatly in my search for literature, a task that might sound easier than it really is, due to

lack of scientific literature covering this matter.

Furthermore, I want to thank veterinary student Daniel Haraldsson for helping me explain the

context of this thesis in a way that is precise and yet can be understood by everyone.

I also want to thank Louise Rehn Winsborg for her support, input and interest in my work. Last but

not least, I want to thank DVM, Aurelie Gram for keeping my mood high, even in periods of

adversity.

6

List of abbreviations The following abbreviations have been used in text or tables: AB: Antibiotics

CRT: Capillary refill time

GI: Gastro-Intestinal

HR: Heart rate

IV: Intravenous route

LATH: Large Animal Teaching Hospital, Copenhagen University, Denmark

MM: Mucous membrane

NSAID: Non-steroid anti-inflammatory drug

P.O.: Per oral route

PF: Peritoneal fluid

RR: Respiratory rate

SD: Standard deviation

Sulfa/TMP: Sulfamethoxazole/Trimetoprim

WBC: Blood cell count

7

List of definitions

The following definitions have been used in text or tables:

Fever: Rectal temperature above 38.5 ºC.

Increased respiratory rate: Respiration rate above 20 breaths/minute.

Medical treatment: Treatment not including abdominal surgery, caecal decompression

can be a part of the medical treatment.

Normal CRT: <2s

Other analgesics: Drugs not included in strong analgesics i.e. spasmolytics or

NSAIDs.

Other diagnoses: Diagnoses other than caecal tympany, that cause acute abdominal

pain.

Other rectal findings: Abnormal rectal findings other than caecal distension.

Strong analgesics: Opioids, dissociatives, alpha2-agonists.

Successful caecal

decompression:

A decompression where intestinal gas emerges through the trocar

or needle after insertion to the caecum.

8

Abstract Background: The safety and usefulness of percutaneous caecal decompression is often debated, but

no comprehensive studies have been published covering this matter.

Objectives: To investigate the effects and complications of caecal decompression.

Method: A retrospective review of clinical records between January 2006 and December 2012 at

the Large Animal Teaching Hospital at University of Copenhagen, Denmark, was performed to

identify the number of horses where caecal decompression had been performed. Clinical data

(diagnosis, pain score, heart rate, respiratory rate, steel band, rectal findings), before and after

caecal decompression, treatment (medical or surgical), complications (fever, peritonitis, diarrhea,

haemorrhage, abscess) and short term survival were retrieved from the medical records. Long term

complications and outcome was investigated by means of a questionnaire.

Statistical comparison was done with Prism 6.

Results: Mortality, due to caecal decompression was not observed. A total of 15.9% of the horses

developed complications. The most common complications included: Fever (9.7%), Diarrhea

(9.0%), and peritonitis (5.5%). After caecal decompression, a significant decrease in heart-rate

(p<0.0001), a decrease in use of strong analgesics (p=0.0030) and an increase in number of horses

with normal rectal findings were observed (p<0.0001). Horses diagnosed with caecal tympany more

commonly (p=0.0133) displayed a decrease in pain score after decompression, than horses with

other causes of acute abdominal pain. Multiple decompressions could not be linked to increased risk

of complications or euthanasia. Long term complications were reported in 12.5% of the horses.

Conclusions: Caecal decompression is effective in reducing pain and improving clinical findings in

horses with caecal tympany. Complications such as fever were observed but were not life

threatening.

9

Resumé Baggrund: Sikkerhed og brugbarhed af trokarisering bliver tit diskuteret, men ingen videnskabelige

studier har været publicerede indenfor dette område.

Formål: At undersøge effekten af og komplikationer ved brug af trokarisering.

Metode: Antal heste der blev trokariseret, på Universitetshospitalet for Produktionsdyr og Hest, ved

Københavns Universitet, i perioden januar 2006 til december 2012, blev undersøgt ved hjælp af et

retrospektivt studie af patientjournaler. Kliniske data (diagnoser, smertevurderinger, hjertefrekvens,

respirationsfrekvens, steel band og rektalfund) både før og efter trokarisering, behandling

(medicinsk eller kirurgisk), komplikationer (feber, peritonitis, diarré, blødninger og bylder) og

overlevelsesrate blev trukket ud af journalerne. Længerevarende komplikationer og udfald blev

undersøgt ved brug af spørgeskema.

Statistiske beregninger blev foretaget i Prism 6.

Resultater: Dødelighed, forårsaget af caecal dekompression, blev ikke observeret. I alt oplevede

15,9% af hestene komplikationer. De mest almindelige var: Feber (9,7%), diarré (9,0%) og

peritonitis (5,5%).

Efter trokarisering blev der observeret et signifikant fald i hjertefrekvens (p<0.0001), et fald i brug

af stærk smertestillende medicin (p=0,003) og en stigning i antal heste med normale rektalfund

(p<0,0001). Heste, diagnosticeret med caecum tympani, udviste hyppigere et fald i smertescore, end

heste med koliksmerter, forårsaget af andre tilstande (p=0,0133). Gentagne trokariseringer kunne

ikke forbindes med en øget risiko for komplikationer eller aflivning. Komplikationer efter

hjemsendelse blev observeret hos 12,5% af hestene.

Konklusion: Trokarisering reducerer effektivt smerte og forbedrer kliniske symptomer, hos heste

med caeum tympani. Komplikationer, såsom feber, blev observeret, men var ikke livstruende.

10

Introduction Percutaneous caecal decompression is a term describing the procedure where a trocar/needle is

passed through the abdominal wall, into the caecum, thereby deflating it. The procedure is used to

treat horses, where a massive accumulation of intestinal gas has caused a pathological distension of

the caecum, causing colic symptoms.

Colic is a clinical sign present in a large number of diseases and disorders that cause acute

abdominal pain of varying degree. Colic is a common problem in horses and it has been reported to

be the most common cause of death in horses (Tinker et al., 1997). Caecal tympany is one cause of

colic, where excessive amounts of bowel gas distend the caecum, causing moderate to severe pain

(Edwards, 2002; Fehr, 2012).

A distended caecum can cause severe pressure on the diaphragm and caudal vena cava, causing

circulatory deficiencies (Edwards, 2002; Fehr, 2012; Mørkeberg, 1929). Furthermore, caecal

tympany can lead to rupture of the caecum (White, 1990a). If left untreated, the horse is therefore at

risk of dying from circulatory or septic shock (Dart et al., 1997; Mørkeberg, 1929).

Caecal decompression is used to reduce pain, facilitate further examination and to prevent rupture

of the caecum in colic horses, where caecal tympany is a primary or secondary problem (White,

1990a).

Percutaneous caecal decompression is performed with a needle or a trocar that is pushed through

the skin and muscles in the right paralumbar fossa, into the caecum. The bowel gas is then

evacuated from the caecum through the needle or trocar, until the pressure is reduced.

Caecal decompression has a long history. It has been used to treat horses with caecal tympany since

the middle of the 18th century (Bouley & Reynal, 1859; Broginez, 1845; Mørkeberg, 1929;

Smedegaard, 2013). The procedure was taught at the Royal Veterinary and Agricultural University

in Copenhagen 100 years ago (Hempel-Jørgensen, 1914), and it is still used and taught.

In recent years however, a debate about caecal decompression has arisen, where the safety and

necessity of the procedure have been questioned1

1 This was discused at the EVECCS congress 31-05-2013.

. The risk of faecal contamination of the

peritoneum, causing a severe infection and peritonitis, has been one of the main concerns.

11

Since documentation of effects and complications of the procedure never has been published, it is

very difficult to find scientific evidence in favour of or against caecal decompression.

The purpose of this study was to describe the use and results of caecal decompression at the Large

Animal Teaching Hospital at the University of Copenhagen, in order to supply scientific data to the

debate concerning whether caecal decompression is a safe procedure, suitable for a modern

veterinary hospital, or if it is indeed an outdated method, belonging to the 18th century.

12

Background This section is intended to give a deeper understanding of how, and why caecal decompression is

performed. The physiological mechanisms of pain induced by caecal distension are explained and

the history of caecal decompression is outlined. It is also intended to show how caecal

decompression is used and why it is believed to have an effect on pain in horses with caecal

distension. Furthermore, it will go through, how caecal decompression can change the rectal

findings in these horses. This is done to explain the logic behind the hypotheses tested. A brief

background of the different procedures for caecal decompression will be presented. A description of

the procedures used at LATH will also be given, since the specific procedure used can affect the

outcome. Since caecal decompression has a long history, its use in a historical perspective will also

be presented.

Caecal tympany and use of caecal decompression

The incidence of colic has been estimated to be 3.5 and 10.6 colic cases per 100 horse years, for

different populations in the USA (Kaneene et al., 1997; Tinker et al., 1997). Since specific

diagnoses seldom are made if the horses have not undergone autopsy or surgery, it is difficult to

estimate the incidence of primary and secondary caecal tympany. Besides tympany, diseases of the

caecum include impaction, rupture, infarction, torsion, abscessation, adhesion, tumour and

intussusception (Dart et al., 1997).

In one epidemiological study, 3.7% of the horses presented with acute abdominal pain at surgical

referral centres had primary caecal disease. Of the horses with primary caecal disease, 10% had

primary caecal tympany. The fatality rate of horses with primary caecal tympany was 6.7%. (White,

1990b)

Kalsbeek (1969) conducted a study of 130 colic horses at Utrecht University. In these horses, caecal

disease was the most common diagnosis and 24 (18.5%) of these horses had caecal tympany.

A retrospective study of 96 cases of caecal disease in horses was conducted by Dart et al., (1997),

but caecal tympany was not investigated. Caecal rupture associated with concurrent unrelated

disease was reported in 13% of the horses, while 5% had rupture with no related disease. Whether

13

these horses had rupture subsequent to untreated caecal tympany, is impossible to tell, but severe

caecal distension can lead to caecal rupture (White, 1990a). In case of a caecal rupture, euthanasia

is indicated, as death is unavoidable (Dart et al.,1997; Hackett, 2012).

History

Caecal decompression has a long history. The use and existence of the trocar has been documented

in Denmark in the late 18th century (Smedegaard, 2013). This trocar was used both for

decompression of the rumen in cattle and the caecum in the horse. The same kind of instrument was

documented in 1820 in Sweden, where a trocar was one of the first surgical instruments at the

newly established Veterinary Institute in Stockholm (Figure 1). Just as in Copenhagen, trocars were

used to treat tympany in both horses and cattle (Dyrendahl, 1995).

Caecal decompression was also described by Broginez (1845), in France.

Mørkeberg (1929) gave

an in depth description

of the trocar and caecal

decompression. At that

time, different models

were developed for

horses, cattle and small

ruminants (Figure 2).

The models designed

for horses were thinner

than those for cattle, in order to avoid leakage of faecal matter from the caecum. The trocar consists

of a sharp obturator and a cannula, the obturator being situated inside the cannula. The procedure

was performed on a non-sedated horse, without any kind of analgesics. According to the author, this

was never a problem since the horses tend to be very depressed and lethargic due to the

cardiovascular compromise at the time of caecal decompression. The area for the incision was

shaved and disinfected, and a sterile trocar was used (boiling was used for sterilisation of the

Figure 1: Trocar for decompression of the caecum and rumen, produced in 1820, Sweden (Museum of Veterinary History, Skara, Sweden, 2013).

14

instruments). After penetrating the abdominal wall and entering the caecum, the obturator was

removed and the gas could be evacuated. Mørkeberg also recommended leaving the trocar in place

with a small plug in the cannula to see if the caecum started to distend again. If no renewed

distension was observed, the cannula could be pulled out. He recommended closing the wound with

a small amount of wadding and collodion2, or suturing it.

The procedure was described as safe, but Mørkeberg described localised or generalised peritonitis

as a possible sequelae. One must remember that this was

before the development of antibiotics and modern

antiseptic routines. According to Mørkebergs description,

the trocar most commonly had three sides and this had

given the instrument its name troisquarts/trocar (from

acus triquerta, meaning three-sided needle). Caecal

decompression is also called caecal trocarization.

Risks in relation to caecal decompression

The use of caecal decompression is not uncontroversial

and the safety and effectiveness of the procedure has been

discussed lately2

and local abscessation are the two most common

problems encountered following caecal decompression.

Cases of peritonitis have been reported (Fehr, 2012; Hempel-Jørgensen, 1914; Mørkeberg, 1929)

but is described to be uncommon, if performed correctly (Dart et al., 1999).

. However, there is little data addressing

the issue. Cellulitis has been mentioned as a possible

sequelae, especially if no antibiotics are infused locally

when retracting the needle/trocar (Edwards, 2002).

Wilkins (2010) states that peritonitis

2 This was discussed at the EVECCS congress 31 May 2013, Copenhagen, Denmark.

Figure 2: Trocars, the one to the left and

the one in the middle are designed for

decompression of large intestine and the

one to the right is designed for

decompression of the rumen.

(Mørkeberg, 1929).

15

Normal white blood cell count in peritoneal fluid is 0.5-5x109 cells/litre (Colahan et al., 1999).

After caecal decompression, white blood cell count in peritoneal fluid can increase dramatically (up

to 200x109 cells/litre) without causing alarm (McIlwraith, 1984).

Ross (1999) states that the clinician must consider the possible risks associated with caecal

decompression, including leakage of digesta with localised peritonitis or contamination of the flank

area with attendant cellulitis. According to McIlwraith (1984), repeated caecal decompressions

should be avoided. Neither should the veterinarian make a second try, in case of the first caecal

decompression being unsuccessful.

The risk of abscessation has also been mentioned (Fehr, 2002; Mørkeberg, 1929). Fever is also seen

after caecal decompression (Fehr, 2002). According to Mørkeberg (1929), phlegmons can develop

if proper antiseptic technique is not applied. Death due to caecal decompression seems to be

uncommon. One single case was mentioned by Broginez (1845), who accidentally punctured an

artery, causing severe bleeding and a fatal outcome.

Caecal anatomy

Dyce et al. (2002) describe the caecum in

the following manner: The base of the

caecum lies in the right dorsal part of the

abdomen, partly against the flank and

partly cosvered by the ribs. It has an

extensive contact with the abdominal

roof from the 15th rib to the tuber coxae.

The caecum consists of an expanded

dorsal base, a curved tapering body and a

blind ventral apex that lies close to the

xiphoid cartilage (See Figure 3 for

anatomical placement). The cranial part

of the base forms an overhanging

enlargement. The organ is often likened

Figure 3: Illustration of the caecum (Modified from Dyce et al., 2002.)

16

to a comma due to its shape. In a large horse, it may have a capacity of over 30 litres, and may

measure a meter or more between extremities.

Microbial fermentation within the caecum produces gas that is normally discharges at intervals to

the right ventral colon. Excessive gas production can cause the overhanging part of the base to press

on the origin of the right ventral colon. This interferes with the normal emptying mechanisms,

resulting in tympany of the caecum. There are four teniae over most of the organ but the number

diminishes towards the apex. The teniae consist of a thickened longitudinal layer of the tunica

muscularis. (Schaller, 2007). The ventral teniae can be palpated during rectal examination

(Edwards, 2002).

Etiology of caecal tympany

Gaseous distension of the caecum can be of primary or secondary origin (Edwards, 2002; Hempel-

Jørgensen, 1914; White, 1990a). Primary caecal tympany develops either due to rapid gas

production or due to reduced caecal motility. Rapid gas production is most commonly seen in

horses that are fed high grain diets, horses on rapidly growing pasture and horses on wilted grass

(Edwards, 2002; White, 1990a). Secondary tympany occurs because of an outflow obstruction

aboral to the caecum. Outflow obstruction can be caused by problems in both large- and small

colon. This can be due to impaction, displacement/torsion, foreign bodies or enteroliths (Edwards,

2002; Hempel-Jørgensen, 1914; White, 1990a).

Physiology of caecal tympany

Distension of the caecum elicits visceral pain by stimulating the stretch receptors in the intestinal

wall (Roelvink et al., 1991). Experiments with mechanical distension of the caecum, by use of

inflatable balloons, have been used to test the effects of analgesics in the horse. The model is

recognized as a satisfactory model to evaluate visceral pain in horses (Lowe, 1978; Roelvink et al.,

1991). The C-fibres in the viscera mediate a dull, poorly localised, painful sensation and are

activated by rapid stretching of the gut (Mair, 2002). Pain is intermittent at first, but becomes

continuous and severe as the distension increases (White, 1990a). The heart rate may be greater

17

than 100 beats/minute (Edwards, 2002; White, 1990a). According to Van Harreveld and Gaughan

(2002), heart rate is a good indicator of pain in horses, and an indirect indicator of the severity of

the condition. Heart rate evaluation should always be used in addition to other findings on the

physical examination. Breathing is also affected by pain (Edwards, 2002; Van Harreveld &

Gaughan, 2002). Caecal tympany causes the caecum to increase in size. This can be recognized by

rectal examination and can make the horse appear bloated with an abnormal rounding of the right

flank (Dart et al., 1999; White, 1990a). When severe caecal distension is present, diaphragm

movement will be restricted, thereby affecting respiration (Edwards, 2002; Hempel-Jørgensen,

1914; Mørkeberg, 1929; White, 1990a). Auscultation with percussion of the right flank reveals a

high pitched, metallic sound (steel band) (Hesselholdt, 1992; White, 1990a). On rectal examination,

the ventral caecal taenia can be palpated, stretching from the right dorsal region, ventrally and to the

left (Edwards, 2002).

Indications for percutaneously caecal decompression

Caecal decompression is indicated in horses with signs of caecal tympany, that can not be resolved

through medical treatment alone (Dabareiner & White, 1997).

In LATHs standard procedure from 2006 its stated that caecal decompression is indicated in colic

horses with primary or secondary caecal tympany (Appendix 2).

Caecal decompression can prevent rupture of the caecum and relieve pressure on the vena cava

(White, 1990a). According to Fehr (2012), caecal decompression can be used for cardiovascular and

respiratory stabilisation in horses with large colon volvulus. Caecal decompression in combination

with placement of a nasogastric tube, has been described as a lifesaving procedure, for horses with

primary caecal tympany or paralytic ileus (Hesselholt, 1992).

Rectal examination has proven useful to predict whether a horse is in need of surgical intervention

or not. (Reeves, 1989; Thoefner et al., 2003; Van Harreveld & Gaughan, 2002). Rectal

examination has been described as the most important part of the clinical evaluation of the colic

horse (Kalsbeek, 1969). Due to the anatomical placement and size of the caecum in the horse, a

distended caecum can render a rectal examination impossible. If the caecal distension is severe, it

18

can be necessary to deflate the caecum, in order to perform a proper rectal examination and

facilitate a more precise evaluation of therapeutic needs (Hesselholt, 1992; White, 1990a).

Since caecal distension can be very painful, decompression may be used for pain relief. The

procedure can also provide more time for medical treatment and resolution in a medical case.

Among other things, this pain relief can prevent the horse from becoming recumbent in the trailer

on its way to a referral hospital for surgery (Fehr, 2012; White, 1990a).

Surgical intervention is rarely necessary to treat caecal tympany if the caecum can be

decompressed by needle (White, 1990a).

Summing up, caecal decompression has been used as a life saving procedure, to facilitate rectal

examination, to relief pain, for cardiovascular and respiratory stabilisation and therapeutically.

Methods for percutaneous caecal decompression

Caecal decompression is most commonly

performed percutaneously (Edwards, 2002; Fehr,

2012; Hesselholt, 1992; Mørkeberg, 1929; White,

1990a). Several different methods for performing

caecal decompression are described in the

literature. Some authors recommend the use of a

15cm, 14G catheter (Dart et al., 1999; Fehr, 2012;

Edwards, 2002).

One author recommends a 14-16G needle (White,

1990a; White, 2006) while others recommend the

use of the Danish military trocar (15x0.4cm)

(Hesselholt, 1992). The large size of the military

trocar has been questioned on the grounds that

this may increase the risk of contamination of the

peritoneum by leakage of caecal fluid (White,

1990a). The same author has discouraged the use

Figure 4: Illustration of caecal decompression

(White, 2006).

19

of 10-12G needles, in order to avoid tearing of the caecum, that could lead to leakage of ingesta into

the peritoneal cavity (White, 2006). Nevertheless, another author encourages use of these needles

(McIlwraith, 1984). Proper clipping and disinfection of the puncture area is recommended, and the

caecal

decompression is performed in the right paralumbar fossa (Hesselholt, 1992; White, 1990a).

Vacuum can be used to assist in the evacuation of gas from the caecum (White, 1990a).

Caecal decompression procedure at the Large Animal Teaching Hospital (LATH)

At LATH, percutaneous caecal decompression is performed, based on the findings during a full

clinical colic examination. These findings include steel band sound in the right paralumbar fossa,

abdominal distension and the presence of an overextended, gas filled caecum in close apposition to

the abdominal wall (Appendix 2).

The standard procedure for caecal decompression at LATH can be seen in Appendix 1.

Decompression is most commonly performed with a military trocar, as illustrated in Figure 4.

Norodine paste (Sulfa/TMP) is used P.O. for all horses receiving caecal decompression.

The procedure was updated 18th October 2009. Before this, a standard procedure from 12th January

2006 was followed. No routine use of antibiotics was described in the standard procedure of 2006.

Figure 4: Military trocar for horses, Ø3x135 mm, stainless steel. KRUUSE, 2013. http://www.kruuse.com/da-

DK/ecom/Hest_produktionsdyr/HEST_specialiseret/Kolikbehandling/

Trokar_hest_stordyr/prod_190370.aspx

20

Gentamicin and/or Ampicillin i.v. were to be used, if gut contents were to escape through the trocar

during extraction. Equibactin (Sulfa/TMP) P.O., Penicillin and Cephalosporin have also been used

to avoid infections. Sterile gloves were used in this protocol (Appendix 2).

21

Transrectal decompression of the caecum Although caecal decompression is most

commonly performed percutaneously, two

per rectum procedures have been described

(Mørkeberg, 1929; Scotti et al., 2013). The

use of Elschners trocar (Figure 5) which is an

approximately 40 cm long, curved trocar, has

been described by Mørkeberg (1929). The

use of a newly developed transrectal

decompression device (Figure 6) has been

described lately (Scotti et al., 2013).

According to Mørkeberg (1929), there is

increased risk of infection after rectal

decompression and hence, this method should

only be used if percutaneous caecal

decompression is impossible, due to the position

of the caecum. Since the needle has to pass two

intestinal walls this could lead to a greater risk of

infections (Van Galen & Pihl, 2013) but this has

not been studied.

Recently, preliminary results from studies of

transrectal decompression have been published.

This was done as a new approach to treating

large intestinal tympany in horses with acute abdominal pain (Scotti et al., 2013).

Horses with both caecal and colon tympany were decompressed one to three times per horse.

Altogether 33 decompressions were made in 25 horses, by use of a transrectal decompression

Figure 5: Elschners trocar for transrectal decompression (Mørkeberg, 1929).

Figure 6: Transrectal decompression device. (Scotti et al. 2013)

22

device connected to an aspiration system that caused negative pressure in the device. Only five out

of 25 horses went through autopsy. Of these horses, three had no evidence of haemorrhage,

abscessation, cellulitis or peritonitis. In the two remaining horses, evaluation was impossible, due to

advanced intestinal deterioration. The study showed no significant difference between heart rates

pre/post decompression. Sadly there is yet no studies performed with in depth evaluations of

outcomes of transrectal decompression.

Medical treatment of the caecal tympany can be successful in cases where the caecum is not

severely distended. Relaxation of the caecum is attempted by administration of xylazine alone or in

combination with butorphanol (Dabareiner & White, 1997).

23

Objectives The major objectives of this study are to describe and investigate the use and the results of caecal

decompression at LATH. Since the specific guidelines used at the hospital, the criteria for when to

perform a caecal decompression and the demographics of the patients (age, sex and breed) could

influence the results seen at this specific hospital, this is interesting and important to describe.

Therefore, this study will consist of a descriptive part and an investigation of the effects and

complications of caecal decompression.

Descriptive part:

1) How often is caecal decompression performed at the LATH and how many times is each

horse decompressed?

2) What age, gender and breed are the horses decompressed at the LATH.

3) What are the indications for performing caecal decompression?

4) What clinical signs are seen in the horses decompressed at the LATH.

5) How is the caecal decompression performed? Which methods are used to avoid sequelae

and complications.

6) Which complications are seen and how common are they?

7) How common is death following caecal decompression?

The aim of the study is not only to describe whether the procedure is effective or not in achieving

the desired results, but also to investigate the possible complications. This will be investigated,

since the effectiveness of the procedure must be compared to the risks.

One of the goals is to investigate whether caecal decompression is a useful method in a modern

veterinary hospital. How useful the procedure is, is determined by the amount of positive and

negative outcomes and whether these are in acceptable proportions to each other. Therefore the aim

is to quantify possible complications, as well as the desired effects?

How effective is caecal decompression?

8) Can caecal decompression be used to reduce pain? In what type of colic is this possible?

24

9) Can caecal decompression decrease the need for strong analgesics?

10) Can caecal decompression be used to decrease symptoms of caecal tympany (steel band,

abdominal distension, dilated caecum at rectal examinations)?

Are there any complications from multiple decompressions?

11) Is there a greater risk of complications if a horse is decompressed more than once?

12) Is there a greater risk of euthanasia if a horse is decompressed more than once?

25

Hypotheses A number of hypotheses have been constructed, in order to investigate the effects of caecal

decompression. The further discussion and conclusions based on these hypotheses are restricted to

cases where the selection of patients for caecal decompression and the following procedures are

conducted in the same manner as at LATH (Appendix 1, Appendix 2).

The following hypotheses will be investigated:

Pain reduction

As described earlier, caecal distension is very painful. The fact that mechanical distension of the

caecum produces visceral pain in the horse is well documented. Therefore it would be logical to

assume that caecal decompression can decrease the distension of the caecum in a manner that

decreases pain in the horse. Heart rate has been described as a good indicator of pain in horses,

therefore one would assume that caecal decompression could lower the heart rate. The balloon

induced colic model was used to evaluate the effects of analgesics by inflicting pain, that could be

treated with different analgesics. When the distension decreases, the need for analgesics should also

decrease. The principle of caecal decompression is to minimize the distension of the caecum.

Therefore the procedure is presumably more effective on horses, where caecal tympany is the

primary cause of acute abdominal pain, than where it is not.

Hypothesis 1: There will be a decrease in heart rate after caecal decompression.

H0= There is no change in heart rate after caecal decompression.

Hypothesis 2: The demand for strong analgesics decreases after caecal decompression.

H0= Caecal decompression has no effect on the demand for strong analgesics.

Hypothesis 3: Horses with caecal tympany will have a longer painfree period, following caecal

decompression, than horses with other causes of acute abdominal pain.

26

H0A= Decompressed horses with caecal tympany have the same prevalance of recurring pain as

decompressed horses with other causes of acute abdominal pain.

H0B= Time between caecal decompression and reoccurrence of pain is the same, in horses

with/without caecal tympany.

Hypothesis 4: Horses with caecal tympany will have a longer period postdecompression, before

readministration of analgesics, than horses with other causes of acute abdominal pain.

H0A= Decompressed horses with caecal tympany have the same prevalence of readministration of

analgesics, as horses with other causes of acute abdominal pain.

H0B= Time between caecal decompression and readministration of analgesics is the same, in horses

with/without caecal tympany.

Hypothesis 5: The prevalence of decreased pain score postdecompression is higher in horses with

caecal tympany, than in horses with other causes of acute abdominal pain.

H0= Decompressed horses with caecal tympany have the same occurence of decrease in pain score,

postdecompression, as horses with other causes of acute abdominal pain.

Hypothesis 6: A decrease in pain score is more common after caecal decompression in horses that

only require medical treatment, compared with horses in need of surgical treatment.

H0= Horses requiring medical treatment have the same decrease in pain score, postcompression, as

horses requiring surgical treatment.

Change of clinical signs Signs of caecal tympany include the presence of steel band sounds on auscultation of the right

flank, abnormal abdominal distension and a large, gasfilled caecum on rectal examination. If caecal

decompression reduces caecal tympany, one could assume that these signs would become less

prominent/disappear.

27

Hypothesis 7: Caecal decompression reduces the prevalence of steel band.

H0= There is no difference in the prevalence of steel band before and after caecal decompression.

Hypothesis 8: Caecal decompression reduces the prevalence of abdominal distension.

H0= There is no difference in prevalence of abdominal distension before and after caecal

decompression.

Hypothesis 9: Caecal decompression enhances the prevalence of “other findings” on rectal

examination.

H0= There is no difference in the prevalence of “other findings” before and after caecal

decompression.

Hypothesis 10: Caecal decompression enhances the prevalence of “normal findings” on rectal

examination.

H0= There is no difference in the prevalence of “normal findings” before and after caecal

decompression

Complications due to repeated caecal decompression The risk of complications following caecal decompression is the main argument for not performing

the procedure. Repeated caecal decompressions have been performed, with no reports of added

complications, even though this is discouraged by one author. Risks accompanying repeated

decompressions have not yet been studied.

Hypothesis 11: Horses decompressed one time have the same prevalence of complications, as

horses having received several decompressions.

The hypothesis is a null hypothesis.

28

Hypothesis 12: Horses decompressed one time have the same mortality, as horses having received

several decompressions.


Hypotheses 13: Horses experiencing complications after caecal decompression have the same

mortality, as horses without postdecompression complications.


Medical and Surgical colic

The position and size of the distended caecum makes it hard or impossible to preform a rectal

examination. Therefore, the distended caecum can hide important rectal findings from the

veterinarian and thus reduce the possibility of making a correct diagnosis and prognosis. If caecal

decompression can reduce the size of the caecum, this would change rectal findings and make it

possible to differ between horses in need of medical and surgical treatment.

Hypothesis 14: Horses, requiring surgical treatment, have the same rectal findings before caecal

decompression, as horses requiring medical treatment.


Hypothesis 15: Post decompression, the rectal findings in horses, requiring surgical treatment, will

differ from the rectal findings in horses, requiring medical treatment.

H0= Post decompression, the rectal findings in horses, requiring surgical treatment, will be the

same as the rectal findings in horses, requiring medical treatment.

Respiratory changes

The distended caecum exerts pressure on the diaphragm, restricting its movement. In order to

uphold the respiratory volume, an increase in respiratory rate is required. The respiratory rate is also

29

increased by pain. If caecal decompression can reduce the pressure on the diaphragm and provide

painrelief, respiratory rate would decrease.

Hypothesis 16: Horses with increased respiratory rate, will have a decrease in respiratory rate after

caecal decompression.

H0= Caecal decompression does not cause any alteration in respiratory rate in horses with increased

respiratory rate.

30

Methods and materials The setup for this study was chosen to be a retroperspective study since this provided a large

amount of data. The study population consisted of horses referred to the Large Animal Teaching

Hospital (LATH) at Copenhagen University. The hospital is located in Zealand, Denmark. Data was

collected from horses that had been referred to the hospital from January 2006, until December

2012. Before 2006, the system for recording clinical observations and data was not completely

standardised.

Medical records of horses that had one or more caecal decompressions performed were gathered by

three methods; either electronically in Vetvision (Electronic booking, billing and recording system

by Novasoft, Aarhus N, Denmark), from a preexisting colic database or manually. All clinical

records for horses found in these searches were manually processed.

Horses, decompressed by LATH staff outside the hospital, were excluded, as they lacked

comprehensive records, compared to hospitalised horses. Decompressed horses of all ages were

included, as well as horses admitted for other reasons than acute abdominal pain. Horses admitted

and decompressed more than once during the study period were included as separate study cases, if

colic episodes were judged to be independent of each other. Only horses receiving caecal

decompressions were included, while horses receiving decompression of other parts of the gut were

excluded. An unsuccessful caecal decompression was defined as a decompression where no gas

emerged through the trocar/needle.

Routine autopsy of dead/euthanised (at LATH) horses was performed by the Faculty of Veterinary

Pathology.

Complications were noted when no other explanation of the clinical findings was more reasonable.

Thus, horses that had fever or peritonitis before the caecal decompression did not have this

symptom/disease noted as a complication of the caecal decompression. In the same manner, horses

that developed peritonitis after laparotomy were not registered as developing peritonitis after the

caecal decompression.

31

Disease causing acute abdominal pain was registered for all horses. For horses that went through

surgery and/or autopsy, the diagnosis obtained from this procedure was used. For the rest of the

horses, the diagnosis suspected by the treating veterinarian was used. Both disease process and part

of the gastrointestinal tract involved were noted. Some horses had more than one diagnosis noted in

the clinical findings. For these horses, two diagnoses were noted. In some cases more than two

diagnoses were presented. Many different findings are often mentioned in the autopsy reports. The

two most probably related to the clinical symptoms were noted.

Use of antibiotics was registered in all horses treated. The initial treatment was noted, even though

the horse might have received other types of antibiotics later on in the treatment. Days on

antibiotics covers days where any type of antibiotics were administered.

A long term follow up was performed by requesting horse owners to complete an online

questionnaire (Appendix 4). A letter with a web-link to the questionnaire (Enalyzer online survey

software, Enalyzer International © 2010, Copenhagen K, Denmark) were sent to the owners billing

address. The horses name and journal number were used for identification of the horse. Horses that

had ultimately been euthanised, or whose owners had already been contacted with similar questions,

for a separate study, were not contacted. The separate study, consisting of a telephone interview,

was conducted by Christophersen (2011), and was centred around the long term outcome following

colic-surgery.

Demographic, clinical, medical, surgical and post mortem details were extracted from the clinical

records and information from the long term follow up was extracted from the questionnaire.

Variables recorded can be seen in Table 1, 2 and 3. Additional variables that were registered but

deemed irrelevant for this study were not presented.

Rectal findings were grouped as 0= normal findings, 1=dilated caecum, 2=dilated caecum + other

findings, 3=other findings. For analysis of rectal examination findings, category 0+1 made up the

group “no other findings” and category 2+3 made up the group “other findings”.

All available information was recorded in a preexisting database (Microsoft Office 2007 Access®,

Microsoft Corporation, Redmond, WA, USA), created by Tina Holberg Pihl at LATH and was

modified to fit this study. Answer categories were created for categorical data. At the end of the

study, the numerical data were checked for abnormal values.

32

Table 1: Demographics, disease, treatment and complications

Variables Description

Demographics Id Study number Journal number Name Breed Sex Age Admission date Admission Time Discharge date

Auto number LATHs unique identification number of the horse Name of horse Breed of horse 0= gelding, 1= mare, 2= stallion In years (months = x/12) dd:mm:yyyy tt:mm dd:mm:yyyy

Disease process Affected portion of GI 1 Disease process 1 Affected portion of GI 2 Disease process 2 Diagnosis Outcome Autopsy diagnosis

1=ventriculus, 2=jejunum, 3=ileum, 4=caecum, 5= colon ascendens, 6=colon descen- dens, 7=rectum, 8=peritoneum, 9=liver, 10=other extraenteral, 11=unknown 0=no pathology seen, 1=simple obstruction, 2=strangulating obstruction, 3=nonstran- gulating infarction (thromboembolism), 4=enterocolitis, 5=ulcer, 6=perforation, 7=tympany, 8=peritonitis, 9=abscess, 10=grass sickness 11=other, 12=unknown Same as “Affected portion of GI 1” Same as “Disease process 1” Clinical diagnosis, i.e. caecal tympany, impaction of pelvic flexure, gastric ulcer 0=survived, 1=died by itself, 2=euthanasia, poor prognosis, 3=euthanasia on owners request. Diagnosis from autopsy, registered when available

Treatment Treatment performed Caecal decompression Caecal decompression number Use of antibiotics Antibiotic type Antibiotic days

0=none, 1=medical, 2=surgical, 3=medical because owner did not want surgery 1=performed once, 2=performed several times Numerical: 1,2,3,4... 0=no, 1=yes, 2= unknown 1=Sulfa/TMP, 2=Penicillin + Gentamycin, 3=Ampicillin, 4=Penicillin, 5=Cobactan (r. generation cephalosporin), 6=Excenel (3. generation cephalosporin), 7=Gentamicin Numerical: 1,2,3,4...

Complications Diarrhea, days after decompression Diarrhea, duration Abscess hospital Pain hospital Swelling hospital Haemorrhage hospital Fever hospital Peritonitis after decompression Peritoneal-fluid, leukocytes before decompression Peritoneal fluid, leukocytes after decompression

In days In days 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes x109 leukocytes/litre x109 leukocytes/litre

33

Table 2: Clinical data concerning caecal decompression


Decompression date Decompression time Duration of colic Pain before Pain after Time from decompression until analgesics Time from decompression until pain MM before decompression MM after decompression CRT before decompression CRT after decompression Heart rate before decompression Heart rate after decompression Respiration rate before decompression Respiration rate after decompression Rectal temperature Borborygmia before Borborygmia after Steel band right side before Steel band right side after Steel band left side before Steel band left side after Distended abdomen before Distended abdomen after Rectal examination before Rectal examination after Analgesics before Analgesics after

dd:mm:yyyy tt:mm 0=<4h, 1=5-12h, 2=13-23h, 3=>24h, 4=unknown 1=mild colic, 2=moderate colic, 3=severe, 4=lethargy 1=mild colic, 2=moderate colic, 3=severe, 4=lethargy minutes, 9999=no renewed administration minutes, 9999=no renewed pain 0=normal (pink), 1=pale, 2=red, 3=cyanotic 0=normal (pink), 1=pale, 2=red, 3=cyanotic Seconds Seconds Beats pr. minute Beats pr. minute Breaths pr.minute Breaths pr.minute Degrees in Celsius 0=normal, 1=decreased, 2=ceased, 3=increased 0=normal, 1=decreased, 2=ceased, 3=increased 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=normal findings, 1=dilated caecum, 2=dilated caecum + other findings, 3=other findings 0=normal findings, 1=dilated caecum, 2=dilated caecum + other findings, 3=other findings 0=none,1=spasmolytics + NSAIDs, 2=NSAIDs, 3=spasmolytics alone, 4=strong analgesics alone, 5=strong analgesics together with other drugs 0=none,1=spasmolytics + NSAIDs, 2=NSAIDs, 3=spasmolytics alone, 4=strong analgesics alone, 5=strong analgesics together with other drugs

34

Table 3: Questionnaire


Demographics Journal number, name Alive at this date Euthanasia reason Date of euthanasia

Identification of the horse 0=alive, 1=dead, 2=lost/sold 0=colic related, 1=not colic related, 2=lost/sold dd:mm:yyyy

Complications Complications comment Abscess home Pain home Swelling home Fever home Diarrhea home

Text 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes 0=no, 1=yes

Statistics

Statistical analysis was performed on Prism 6 (GraphPad Software, Inc © 2013) and on Wizard for

Mac (Evan Miller © 2013). Mean- and SD-values were calculated to describe numerical data and

percentages to describe grouped data. Statistical analysis was performed using Chi-square test to

detect differences between groups in frequency data. Fisher's exact test was used for the same

purpose, when there were 5 or less horses in one of the categories. Paired t-tests were used to

compare changes in clinical, numerical variables before and after caecal decompression. Unpaired t-

tests were used to compare differences between groups. The null hypotheses were declared true if

p<0.05 and were dismissed if p>0.05. Linear regression a corresponding graph was used for

illustrative purposes.

35

Results

Case material

In the period between 01. January 2006

and 31. December 2012, a total of

1422 horses were referred to LATH

with acute abdominal pain

(Christophersen et al. 2014; Pihl,

2013).

Out of these 1422 horses, 155 horses

were registered as having received a

decompression in the period 2006-

2012. Two horses were excluded from

the study, since critical information

about the caecal decompression was

not available in the clinical

registration.

One horse was excluded, since only the

colon was decompressed. Seven horses

were excluded, since the caecal

decompression was performed by

LATH staff outside the hospital

facilities by the Large Animal Field

Service.

Thus, a total of 145 horses (10.2% of

the referred colic horses in 2006-2012)

were included in this study.

The two breeds most commonly represented were Danish Warmblood and Icelandic horses.

Table 4: Demographics for horses, included in the study

Demographics Categories Number of horses

Percentages

Breed/Type Warmbloods Ponies Coldbloods Missing Total

106 28 10 1 145

73.1% 19.3% 6.9% 0.7% 100%

Gender Mare Gelding Stallion Total

71 64 10 145

49.0% 44.1% 6.9% 100%

Age 0-5 years 6-10 years 11-15 years 16-20 years 20+ Unknown Total

39 60 27 14 2 3 145

27.5% 41.4% 18.6% 9.7% 1.4% 2.1% 100%

Admission month

December January February

Total winter March April May

Total spring June July August Total summer September October November Total Autumn Total

20 12 13

45 17 9 5

31 12 8 10

30 7 16 16

39 145

13.8% 8.3% 9.0%

31.0% 11.7% 6.2% 3.5%

21.4% 8.3% 5.5% 6.9%

20.7% 4.8% 11.0% 11.0%

26.9% 100%

36

Ages ranged from 3 months to 26 years, with a mean of 8.9 years and a SD of 4.85 years. The

genders were distributed as follows; mares 49.0%, geldings 44.1% and stallions 6.9%. For detailed

information of the demographics, see Table 4.

Registrations of gastrointestinal tract diseases Diseases causing the acute abdominal pain were registered in all 145 horses. Disease process and

part of the gastrointestinal tract affected were registered. If the horse had developed more than one

disease, the primary cause was registered as “Disease 1” and the secondary was registered as

“Disease 2”. If two, separate primary diseases occurred at the same time, the most severe was

registered as “Disease 1”.

Table 5: Diseases, diagnosed as cause of acute abdominal pain

Diseases Disease process 1

Percentages Disease 1

Disease process 2

Percentages Disease 2

Total occurrence

Percentages of horses

Simple obstructions Large colon impaction Large colon displacement without strangulation Caecal impaction Small intestinal incarcerations without strangulation Ventricular overfilling/impaction Small intestinal impaction

33 25 2 2 2 -

22.8% 16.6% 1.4% 1.4% 1.4%

6 2 3 - 2 1

6.8% 2.3% 3.4% 2.3% 1.1%

39 27 5 2 4 1

26.9% 18.6% 3.4% 1.4% 2.8% 0.7%

Tympany Caecal tympany Large colon tympany

28 6

19.3% 4.1%

44 3

50% 3.4%

72 9

49.7% 6.2%

Strangulations Large intestinal strangulations Thromboembolic infarcts Small intestinal strangulations Ceacal torsion with strangulation

17 5 4 -

11.7% 3.4% 2.8%

- - 1 1

1.1% 1.1%

17 6 4 1

11.7% 4.1% 2.8% 0.7%

Infections Peritonitis Enteritis

3 9

2.1% 6.2%

14 4

15.9% 4.5%

17 13

11.7% 9.0%

Perforations/ruptures 3 2.1% 2 2.3% 5 3.4%

Ventricular ulcers 1 0.7% 1 1.1% 2 1.4%

Other 4 2.8% 4 4.5% 8 5.5%

Unknown 1 0.7% - 1 0.7%

Total 145 100% 88 100% - -

37

A total of 72 horses had caecal tympany and 44 of these had caecal tympany in combination with

other findings, such as impaction or displacement of the large intestine. In these cases the

obstruction was registered as the primary disease and the caecal tympany as the secondary disease.

No caecal ruptures were diagnosed at

autopsy.

Caecal tympany was the most

common diagnosis among horses

decompressed. Other common

diagnoses included large colon

impaction and large colon

displacement without strangulations.

Some horses had simultaneous

disease, unrelated to the caecal

tympany. See Table 5 for further

details.

Details about the clinical findings,

before caecal decompression, are

registered in Table 6 A+B. Not all

clinical findings were available in the

clinical registrations. The total number

registered is noted for all the

parameters. Degree of pain was

registered in 139 horses and 64 of

them (46.0%) were in mild pain.

Mucous membrane colour was normal

in 51 horses (43.6%) and red in 43

(36.8%). CRT was normal (<2 s) in 64 horses (55.7%) and slightly elevated in 42 horses (36.5%).

Borborygmia was decreased/ceased in 81 (58.3%) and 42 horses (30.2%) respectively. Steel band

in the right flank was a common finding, being registered in 109 horses (80.1%), while steel band in

the left flank was less common, only registered in 18 horses (14.5%). “No faeces” was a common

Table 6A: Clinical findings before caecal decompression

Parameter Categories No. of horses Percentages

Degree of pain No pain Mild pain Moderate pain Severe pain Apathetic Total registered

23 64 24 19 9 139

16.5% 46.0% 17.2% 13.7% 6.5%

MM colour Normal Pale Red Cyanotic Total registered

51 18 43 5 117

43.6% 15.4% 36.8% 4.3%

CRT <2 s 2-3 s 3-4 s 4-5 s Total registered

64 42 7 2 115

55.7% 36.5% 6.1% 1.7%

Duration of colic ≤4 h (acute) 5-12h 13-23h ≥24h Unknown Total registered

7 40 27 43 28 145

4.8% 27.6% 18.6% 29.7% 19.3%

Gastric reflux <5 l 5-10 l >10 l Total registered

90 11 10 111

81.1% 9.9% 9.0%

Temperature <37.0 ºC 37.0-38.5 ºC >38.5 ºC Total registered

13 88 15 116

11.2% 75.9% 12.9%

38

finding, and this was noted in 46 horses (39.3%). At rectal examination, a dilated caecum was the

most common finding. A total of 49 horses (40.2%) had a dilated caecum with no other findings,

and 46 horses (37.7%) had a dilated

caecum and “other findings”.

A total of 59 horses that were

examined rectally both before and

after caecal decompression had other

findings after caecal decompression.

In 22 (37%) of

these horses the first rectal

examination showed only caecal

distension.

Before caecal decompression, the

following findings were present.

Respiratory rates ranged from 8 to 76

breaths/minute, with a mean of 24

breaths/minute and an SD of 13.4

breaths/minute. Heart rates ranged

from 28 to 100 beats/minute, with a

mean of 61.9 beats/minute and an SD of 16.9 beats/minute. Rectal temperatures ranged from 35.7

ºC to 39.8 ºC, with a mean of 37.8 ºC and an SD of 0.715 ºC.

Treatment and outcome

Medical treatment was the most common treatment among horses receiving caecal decompression.

Medical treatment was administered in 87 horses (60.0%) because of clinical findings. Surgical

treatment was performed in 30 horses (20.7%) and 28 horses (19.3%)

Table 6B: Clinical findings before caecal decompression

Parameter Categories No. of horses Percentages

Borborygmia Normal Decreased Ceased Increased Total registered

8 81 42 8 139

5.8% 58.3% 30.2% 5.8%

Steel band right No Yes Total registered

27 109 136

19.9% 80.1%

Steel band left No Yes Total registered

106 18 124

85.5% 14.5%

Rectal Findings Normal Dilated caecum Dilated caecum + other Other findings Total registered

2 49 46 25 122

1.6% 40.2% 37.7% 20.5%

Distended abdomen

No Yes Total registered

21 115 136

15.4% 84.8%

39

were treated medically, because

owners did not want the horse to

undergo surgery even though this was

advised. Survival rates were highest for

horses treated medically (82.8%). For

horses treated surgically, the survival

rates were lower (53.3%), since many

(40.0% of the surgical patients) were

euthanised because of poor prognosis.

Survival rates were the lowest (14.3%)

for horses that received medical

treatment because the owner did not

want surgery. For further details of the

outcome and treatment, see Table 7.

Systemic antibiotic use was registered in 120 horses. Eighteen horses were not treated, since they

were euthanised/died within hours from the procedure. The remaining 7 horses did not receive

antibiotics, according to their clinical registrations. Penicillin + Gentamycin was used in 38.3% of

the horses decompressed and Sulfa/TMP was used in 26.7% of the horses. These two combinations

of antibiotics were the most common antibiotic treatments, see Table 8 and Graph 1 for detailed

information of antibiotics used for systemic treatment. Antibiotics were usually administered for

three days. For further details, see Table 9 and Graph 2.

Table 7:Treatment given and survival rates

Treatment No. of horses Percentages

Medical Survived until discharge date Died by itself Euthanasia Surgical Survived until discharge date Died by itself Euthanasia Medical because owner did not want surgery Survived until discharge date Died by itself Euthanasia Total

87 72 2 13 30 16 2 12 28 4 0 24 145

60.0% 82.8% 2.3% 14.9% 20.7% 53.3% 6.7% 40.0% 19.3% 14.3% 0% 85.7% 100%

Table 8: Antibiotics used Antibiotics No. of

horses

Sulfa/TMP 32

Penicillin + Gentamycin 46

Ampicillin 6

Penicillin 10

Cobactan 19

Excenel 0

Gentamycin 7

Total 120

Graph 1: Antibiotics used

40

A total of 183 caecal

decompressions were performed on

145 horses, with 32 horses receiving

more than one caecal

decompression (See table 8). The

average number of caecal

decompressions/horse was 1.26.

A total of 166 decompressions

(90.7%) were successfully

performed. See Table 10 for

unsuccessful decompressions.

One horse had both its caecum and

colon decompressed, the

decompression of the colon was

excluded from the dataset.

Complications

Complications that could be related

to caecal decompression were

observed in 23 (15.9%) out of 145

horses, with some horses having

more than one reported

complication. Fever developed in 14

horses (9.7%), diarrhoea in 13

Table 11: Complications registered at LATH

Complications No. of horses affected

Total no. Percentages affected

Any complications

23 145 15.9%

Fever 14 145 9.7%

Diarrhea 13 145 9.0%

Peritonitis 8 145 5.5%

Swelling 6 145 4.1%

Tissue damage 4 145 2.8%

Haemorrhage 3 145 2.1%

Pain 2 145 1.4%

Abscess 1 145 0.7%

Death due to caecal decompression

0 145 0.0%

Any complications, 2006 protocol

9 74 12.2%

Any complications, 2009 protocol

14 71 19.7%

Table 9: Days on systemic antibiotics Days on antibiotics No. of

horses

< 3 days 24

3 days 65

4-7 days 26

> 7 days 5

Total 120

Graph 2: Days on antibiotics

Table 10: No. of caecal decompressions per horse

No. of caecal decompressions

No. of horses

Percentages

1 2 3 4 5

113 28 2 1 1

77.9% 19.3% 1.4% 0.7% 0.7%

183 145 100%

41

horses (9.0%) and peritonitis in 8 horses (5.5%). These were the three most common complications.

Swelling in the area of caecal decompression was observed in 6 horses (4.1%) and pain in the area

was observed in 2 horses (1.4%). Tissue damage was registered in 4 horses (2.8%), when the

veterinarian had hit other structures than the caecum, such as the ribs. Haemorrhage after hitting a

blood vessel with the needle/trochar was reported in 3 horses (2.1%). These bleedings resulted in

haematomas . The treating veterinarian was able to stop the bleeding in all three cases. Only one

horse (0.7%) developed an abscess in the area of caecal decompression. Caecal decompression was

not found to be the cause of death in any horse. Complications were seen in 14 cases (19.7%) with

the new protocol, and in 9 cases (12.2%) with the old protocol. Se Table 11.

Two sets of standard procedures were used, issued in 2006 and 2009. There was no significant

difference (p=0.2131) in the occurrence of complications between these two standard procedures.

Questionnaire

A letter, requesting participation in

the questionnaire was forwarded to

96 horse owners. Ten letters were

returned as the owner were

untraceable. Furthermore three

owners responded they were unable

to complete the questionnaire (See

Appendix 3 for the letter and

Appendix 4 for the questionnaire).

One owner could not answer the

questionnaire online and received it

by letter instead. A total of 83

questionnaires were delivered, and

32 of these (38.6%) were answered.

See Table 12 for complications

reported in questionnaire.

Table 12: Complications reported through questionnaire

Complications No. of horses affected

Total no. Percentages affected

Any complications 4 32 12.5%

Fever home 3 32 9.4%

Pain home 1 32 3.1%

Swelling home 1 32 3.1%

Diarrhea 1 32 3.1%

Abscess home 0 32 0.0%

Table 13: Long term survival

Long term survival No. of horses Total no. Percentages

Horse alive at the date of the questionnaire: Yes No Do not know

18 10 4

32 32 32

56.3% 31.3% 12.5%

Colic related euthanasia: Yes No

4 6

10 10

40.0% 60.0%

Time from discharge date until euthanasia: <1 week 1 week-1 month 1-3 months 3-9 months 9-12 months >1 year

1 - 3 - 2 4

10 10 10 10

10.0% 30.0% 20.0% 40.0%

42

More than one complication per horse was reported in 12.5% of the horses. Fever was the most

common complication reported. No case of abscess in the area was reported.

A majority of the horses were still alive and only 12.5% of the horses had been euthanised because

of circumstances related to colic. Long term survival was unknown in 4 horses (12.5%). These

horses had been sold, and the previous owner had no contact with the new owner. See Table 13 for

further details.

Pain reduction after caecal decompression

A total of 114 horses had registrations of heart rates, both before and after the first caecal

decompression.. Heart rate before caecal decompression ranged between 28-100 beats/minute, the

mean being 62.46 beats/minute, with an SD of 16.46 beats/minute. Heart rate after caecal

decompression also ranged between 28-100 beats/minute, the mean being 53.11 beats/minute, with

an SD of 14.13 beats/minute (Graph 3). There was a significant difference in heart rate (p<0.0001)

after caecal decompression (Graph 4).

Graph 3: Change in heart rate, illustrative Graph 4: Change in heart rate

43

Registrations of analgesic use pre-

decompression were available in 129 cases,

while 132 were available post-decompression.

There was a significant decrease (p=0.0039)

in the use of strong analgesics after caecal

decompression (Table 14 and Graph 5).

Some horses received caecal

decompression without their clinical

records mentioning a diagnosis of

caecal tympany as the cause of acute

abdominal pain. In the following, these

horses will be referred to as “horses

with other diagnoses”.

A total of 27 horses (18.6%) had no

pain relapse after caecal

decompression. Of these horses, 20 had

the diagnosis of caecal tympany, while

7 had “other diagnoses”.

Horses, diagnosed with caecal tympany, had a significantly lower reoccurrence of pain, than horses

with “other diagnoses” (p=0.0458). No significant difference (p=0.0621) in time, from caecal

decompression until pain relapse, was observed between horses of the two groups (Graph 6).

Graph 5: Use of strong analgesics

Table 14: Changes in use of strong analgesics

Strong analgesics

Other/no analgesics

Total

Before 97 32 129

After 77 55 132

Total 174 87 261

44

A total of 12 horses had no renewed administration of analgesics, at any time after the caecal

decompression, until discharge from LATH. Of these horses, 9 were diagnosed with caecal

tympany, while the remaining 3 had “other diagnoses”. The difference in occurrence of re-

administration between the two groups was insignificant (p=0.223).

Horses, diagnosed with caecal tympany had a mean time from caecal decompression until re-

administration of analgesics of 484.5 minutes, with an SD of 101.3 minutes, compared to horses

with “other diagnoses” that had a mean time of 225.5 minutes, with an SD of 43.68 minutes. Horses

with caecal tympany had a significantly (p<0.0001) longer time between caecal decompression and

re-administration of analgesics (Graph 7).

Graph 6: Time until pain

45

Information about severity of abdominal pain, both before and after caecal decompression, was

available for 126 horses. Of these horses, 66 had been diagnosed with caecal tympany and the

remaining 60 had “other diagnoses” (Table 15). A decrease in pain score after caecal

decompression was more common in horses diagnosed with caecal tympany, than in horses with

“other diagnoses”. The difference was significant (p=0.0133), see Graph 8.

Horses receiving caecal decompression were

assigned into three groups; those receiving

medical treatment (Group 1), those receiving

surgical treatment (Group 2) and finally, those

who received medical treatment on request of

the owner, even though surgical treatment

was advised (Group 3) See Table 16.

A significantly larger proportion (p=0.0179)

of horses in Group 1 had a decrease in pain

score compared to Groups 2 and 3 (Graph 9).

Table 15: Changes in pain scores in horses with/without caecal tympany

Pain score down

No change/ pain score up

Total

Caecal tympany

39 27 66

Other diagnoses

22 38 60

Total 61 65 126

Graph 7: Time until administration of analgesics

46

Change of clinical signs after caecal decompression A total of 117 paired registrations of steel band (Yes/No) in the right flank, before and after caecal

decompression, was available (Table 17). There was a significant decrease (p<0,0001) in the

prevalence of steel band, after caecal decompression (Graph 10).

Graph 8: Change in pain score

Graph 9: Pain score change

47

A total of 89 paired registrations of abdominal distension (Yes/No), before and after caecal

decompression, was available (Table 18). There was a significant decrease (p<0,0001) in the

prevalence of distension, after decompression (Graph 11).

Table 17: Steel band in the right flank, before and after caecal decompression

Steel-band

No steel-band

Total

Before decompression

88 29 117

After decompression

20 97 117

Total 108 126 234

Graph 11: Abdominal distension

Graph 10: Steel band

Table 16, Changes in pain scores, horses with/without need for surgery

Treatment Pain score down

No change/ pain score up

Total

Medical treatment

45 31 76

Surgical treatment

10 19 29

Medical, owner do not want surgery

17 15 32

Total 72 65 132

Table 18: Abdominal distension, before and after caecal decompression

Distension No Distension

Total


72 17 89

After decompression

26 66 89

Total 95 83 178

48

A total of 88 paired registrations of rectal

examinations, before and after caecal

decompression, was available. There was no

statistical difference (p=0.0837) in the prevalence

of “other rectal findings” before and after caecal

decompression (Table 19).

There was a significant increase (p<0,0001) in the

prevalence of normal rectal findings after caecal

decompression (Table 20, and Graph 12).

Table 20: Rectal examination

Normal rectal findings

Distended/other findings

Total


1 87 88

After decompression

16 72 88

Total 17 159 176

Table 19: Rectal examination

No other findings

Other findings

Total


37 51 88

After decompression

26 62 88

Total 63 113 176

Graph 12: Normal rectal findings

49

Complications due to caecal decompression

Data from all horses in the study were used

to investigate the prevalence of

complications. There was no significant

difference (p=0.6122) in the prevalence of

complications, between horses

decompressed once, and horses

decompressed several times (Table 21).

Data from all horses in the study were used

to investigate the prevalence of

euthanasia/death. There was no significant

difference (p=0.8266) in prevalence of

euthanasia/death between horses

decompressed once, and horses

decompressed several times (Table 22).

Data from all hoses in the study were used to

investigate the relationship between

complications and mortality. Significantly fewer

horses with complications were euthanised/died

(p=0.0010) than horses without complications.

Mortality was 13.0% in horses with

complications (Table 23). Two of the three horses

had massive sand impactions, diagnosed at

autopsy. The last horse was euthanised. At

autopsy, it was diagnosed with oedematous typhlocolitis and peritonitis as well as two abscesses in

the omentum. At peritoneal fluid collection, a piece of the omentum passed through the puncture,

through the abdominal wall. The horse was still bleeding from the wound 18 hours after the

accident. The horse was euthanised 6 days after the accident.

Table 23: Complications and risk of euthanasia/death

Survived Euthanasia/ died

Total

Complications 20 3 23

No complications

72 50 122

Total 92 53 145

Table 22: Number of decompressions and euthanasia/death

Survived Euthanasia/ died

Total

One decompression

73 40 113

Two or more decompressions

20 12 32

Total 93 52 145

Table 21: No. of decompressions and complications

No complications

Complications Total

One decompression

96 17 113

Two or more decompressions

26 6 32

Total 122 23 145

50

No significant difference (p=0.2338) in the occurrence of diarrhea could be linked to the antibiotics

used.

Medical and Surgical colic

There was no significant difference (p=0.5346) in the distribution of rectal findings, between horses

in need of medical treatment and horses in need of surgical treatment, before caecal decompression

(Graph 13, Graph 14).

Graph 13: Rectal findings before caecal decompreesion

Graph 14: Rectal findings after caecal decompreesion

51

After caecal decompression, there was a significant

difference (p=0,0011) in the distribution of rectal

findings, between horses in need of medical treatment

and surgical treatment. Normal rectal findings and

distended caecum were significantly (p<0.0001) more

common in the horses that only needed medical

treatment (Table 24).

Respiratory changes

A total of 50 paired respiratory rates, before and after caecal decompression, were available. A total

of 19 of these had a respiratory rate higher than 20 breaths/minute.

In horses with a respiratory rate above 20, prior to caecal decompression, the respiratory rate before

and after caecal decompression was compared. In these horses, the respiratory rate before was

significantly (p=0.0035) higher (mean=37.16, SD=12.98) than after caecal decompression (mean=

24.00, SD=10.62). See Graph 15.

In horses with a respiratory rate of 20 or less, prior to decompression, there was no significant

(p=0.0696) difference in respiratory rate, before (mean=14.52, SD=3.69) and after (mean=16.74,

SD= 5.62) caecal decompression.

Table 24: Differences in rectal findings after caecal decompression in horses receiving medical/surgical treatment

Rectal findings Medical Surgical

Normal rectal findings

13 -

Distended caecum 10 -

Distended caecum + other findings

4 3

Other findings 27 25

Graph 15: Changes in respiratory rate

52

Discussion While different statements regarding the effects of percutaneous caecal decompression exist in

veterinary textbooks, no comprehensive reports have been published. The risk of complications is a

great concern among veterinarians, who are reluctant to perform caecal decompression.

This study investigated the effects and complications of caecal decompression in a large number of

horses at the Large Animal Teaching Hospital (LATH), University of Copenhagen. The time span

was delimited to the period from 01. January 2006 to 31. December 2012.

This limits the amount of horses in the study population, but was done for two main reasons: The

clinical record system and billing system at LATH was reorganised in 2005, therefore, not all of the

clinical records were available in the old system. Furthermore, as the data collection was initiated in

2013, horses receiving caecal decompression after 2012 were not included.

A total of 1422 horses were referred to LATH with acute abdominal pain (Christophersen et al.,

2014; Pihl, 2013) in this period. Of these horses, 145 (10.2%) had one or more caecal

decompression performed, during their stay at the hospital and were included in the study.

A total of 183 caecal decompressions were performed, of which 90.7% were successful. The

number of decompressions per horse ranged from one to five with an average of 1.26

decompressions per horse. Repeated caecal decompressions have been discouraged (McIlwraith,

1984). In spite of this, horses that received multiple caecal decompression did not have a

significantly (p=0.6122) higher risk of complications. There was no significant (p=0.8266 )

difference in the risk of euthanasia/death between horses decompressed once, versus several times.

There does not seem to be an increased risk, accompanying repeated caecal decompression.

Indications for caecal decompression

The most common diagnosis among horses receiving caecal decompression was caecal tympany

(49.7%). Secondary caecal tympany (30.3%) was more commonly diagnosed than primary caecal

tympany (19.3%). Caecal tympany was probably under diagnosed in this study, since signs of

caecal tympany reported before caecal decompression were more common than the diagnosis. At

percussion auscultation, steel band sound was present in the right flank of 80.1% of the horses

53

auscultated before caecal decompression. Abnormal abdominal distension was present in 84.8% of

horses evaluated and 77.9% of the horses had a dilated caecum when rectally examined before

decompression.

The underestimation of caecal tympany as a diagnosis may be explained by the following reasons:

If the horse suffered from multiple diseases, where caecal tympany was a secondary problem, only

the primary/most severe diagnoses may have been noted. Caecal tympany was not registered in any

autopsy report, included in this study. Since caecal tympany would normally be undetectable at

autopsy, after caecal decompression, horses could have caecal tympany at the time of caecal

decompression, although undetectable at autopsy.

Other diseases commonly diagnosed included large colon impaction (26.9%) and large colon

displacement without strangulation (18.6%). These diagnoses could be made either at autopsy,

during surgery or by the treating veterinarian. These diseases can cause secondary caecal tympany

(Edwards, 2002; Hempel-Jørgensen, 1914; White, 1990a).

In a retrospective study of 96 horses with caecal disease, Dart et al. (1997) discovered that 18% of

the horses had caecal rupture, without any explanation. Other horses had been diagnosed with

caecal ruptures, due to caecal impaction or parturition. All of the horses with ruptured caecum were

euthanised or died. Caecal tympany was not diagnosed and apparently, percutaneous caecal

decompression was not performed on any of the horses in this study. It is impossible to conclude

whether these horses suffered from a ruptured caecum due to undiagnosed caecal tympany.

Caecal decompression can prevent rupture of the caecum (White, 1990a; Edwards, 2002). None of

the horses receiving caecal decompression at LATH suffered from caecal rupture, further enforcing

this theory.

Caecal decompression is a relatively easily performed procedure. This is illustrated by the fact that

90.7% of caecal decompressions in this study were successful, evacuating gas and thus decreasing

caecal pressure.

54

Effects of caecal decompression

Heart rate is a good indicator of pain in horses (Van Harreveld & Gaughan, 2002). A significant

decrease (p<0.0001) in heart rate was detected after caecal decompression, indicating that caecal

decompression can be used for pain relief. Alternatively, the decrease in hear rate could have been

caused by the use of analgesics. Countering this argument, a significant decrease (p=0.0039) in the

use of strong analgesics was also observed. Of the horses receiving caecal decompression, 18.7%

had no relapse of pain. This indicates that caecal decompression actually had an effect on pain in

these horses.

Differences in the effect of caecal decompression were seen, between horses diagnosed with caecal

tympany and horses with “other diagnoses”. This may be explained by two reasons: Caecal

decompression in a horse with secondary caecal tympany may not influence pain score, if the horse

simultaneously suffers from other, more painful conditions. Further, if a horse is decompressed

without suffering from caecal distension this, of course, will not have any positive effects.

Horses with the diagnosis caecal tympany and horses with “other diagnoses” were compared.

Horses with caecal tympany had a significantly (p=0.0458) lower prevalence of pain relapse after

decompression, significantly (p<0.0001) longer time interval until renewed administration of

analgesics and more commonly (p=0.0133) experienced a decrease in pain score after

decompression. This indicates that the pain reducing effect of caecal decompression is most

pronounced in horses, where caecal tympany is the dominating cause of pain.

When comparing time until renewed pain after caecal decompression, between horses with and

without the diagnosis caecal tympany, no statistical difference was detected. The pain free period

can end in pain or, alternatively at discharge from LATH. This means that a horse that is

successfully treated and subsequently discharged, will have a short “time until pain”, since the true

length of the pain free period was not monitored. The results from this statistical test would

probably be different if the horses were observed for a longer period after discharge. This was not

possible with this study design.

Decreases in pain score after caecal decompression were significantly (p=0.0179) more common in

horses that only needed medical treatment than in horses in need of surgery. This indicates that pain

55

from the primary disease (other causes of abdominal pain) can be so great, that it overrules the pain

relieving effect of caecal decompression.

Pain has been proven to be a good indicator of whether a horse is in need of immediate surgery or

not (Thoefner et al., 2000). Therefore it can be important to decompress the tympanic caecum for

diagnostic purposes and before decision for surgery is made. Otherwise, pain from the caecum

could lead to misinterpretations of findings.

After caecal decompression, no significant difference (p=0.0837) in the prevalence of “other

findings” at rectal examination was observed. Even though this was not significant, 22 horses had

their rectal findings changed from “caecal distension” to “other findings” after decompression -

findings that were impalpable before. Rectal examination has been described as the most important

part of the clinical evaluation of the colic horse (Kalsbeek, 1969), as well as a good indicator for

predicting the necessity of surgery (Thoefner et al., 2003; Van Harreveld & Gaughan, 2002).

Therefore, in these cases, caecal decompression is necessary, in order to facilitate proper

diagnostics of horses with acute abdominal pain and caecal distension.

Horses with elevated respiratory rates prior to caecal decompression had a significant (p=0.0035)

decrease in respiratory rate after decompression. This can be explained by reduced pain or static

pressure on the diaphragm (White, 1990a). Just as the heart rate, respiratory rate has been proven

useful in predictive models, deciding prognosis for colic horses (Reeves et al., 1989). The true

heart and respiratory rates of the colic horse can thus be masked by the pain and pressure resulting

from caecal tympany, making a correct clinical evaluation and prognosis difficult.

Therefore, caecal decompression is necessary to make a correct clinical evaluation of the horse with

caecal tympany.

Complications of caecal decompression

Short term complications, possibly caused by caecal decompression, were seen in 15.9% of horses

decompressed. In the long term follow up, 12.5% of the horses decompressed were reported to have

experienced complications. It is unsure whether these complications were caused by caecal

decompression or not. Fever has been reported as a short term complication to caecal

56

decompression (Fehr, 2002), and was the most commonly observed complication in this study, seen

in 9.7% of the horses at LATH, and reported in 9.4% in the questionnaire.

Diarrhea has not been mentioned as a possible complication to caecal decompression in the

literature. However, in this study it was the second most common complication recognised at LATH

(9.0%). The reason for this could be the use of systemic antibiotics ad part of the standard

procedure at LATH. Antibiotics can disrupt the normal gastrointestinal microbiota, causing

antibiotics-associated diarrhea (Harlow et al., 2013). No significant (p=0.2338) correlation between

the type of antibiotic administered after caecal decompression, and the development of diarrhea

were detected. There was no significant (p=0.2131) correlation between whether the horse was

treated with caecal decompression before or after the implementation of the 2009 standard

procedure. As the standard procedure was updated, so were the guidelines for the use of systemic

antibiotics after caecal decompression. The recommendations were changed from Gentamicin in

case of faecal contamination only, towards standardised administration of Sulfa/TMP.

Risks and benefits of not using systemic antibiotics after caecal decompression were not

investigated during this study due to the small number of horses not treated. Neither were changes

in total leukocyte count in peritoneal fluid after caecal decompression, since only 7 paired counts

were available.

Peritonitis has been described by several authors (Fehr, 2002; Hempel-Jørgensen, 1914; Mørkeberg,

1929). In this study, peritonitis developed in 5.5% of horses after caecal decompression.

Other complications included swelling in the area of insertion of the trocar (4.1%), tissue damage

(2.8%), pain in the area of insertion of the trocar (1.4%) and abscessation (0.7%).These findings

were most likely related to caecal decompression. Swelling and pain in the area were interpreted as

signs of local inflammation.

Death due to blood vessel perforation has been reported (Brogniez, 1845). At LATH, varying

degrees of haemorrhage (haematomas), caused by such perforation, occurred in 3 horses (2.1%). In

all cases haemostasis was achieved (pressure and ice) by the treating veterinarian and no fatality

occurred. No horse was concluded dead due to caecal decompression.

Complications, such as peritonitis and diarrhea, can be fatal for the affected horses (Davis, 2003;

Stewart, 2010). Horses with complications did not seem more likely to be euthanised. Actually a

57

significant (p=0.0010) correlation between absence of complications and mortality was observed.

The most reasonable explanation of this finding is that horses that were euthanised/died shortly after

caecal decompression had no time to develop complications, such as diarrhea, peritonitis or fever.

Mortality was 13.0% (3 of 23) in horses with complications. Two of the three horses with

complications suffered from massive sand impactions and this was the reason for the

euthanasia/death. The last horse was euthanised and later diagnosed with peritonitis and

oedematous thyphlocolitis. From the autopsy report and the clinical findings it was not possible to

conclude whether it was likely to be developed due to caecal decompression, the accident during

peritoneal fluid collection or by other reasons. Abscesses were discovered in the omentum at

autopsy, probably caused due to the omentum slipping through the puncture canal at peritoneal fluid

sampling.

Limits in this study The extent of complications revealed in this study can be debated. Complications were noted when

no other explanation of the clinical findings seemed more plausible. This means that horses that

were presented with fever before caecal decompression, were not noted as developing fever due to

caecal decompression even though they still had fever after decompression. Furthermore, this

means that the number of horses that possibly develop fever after caecal decompression will be

lower if a lot of horses have fever before caecal decompression. One could argue that horses with

clinical signs in accordance to the complications investigated, or diseases that could cause these

signs, should be excluded from statistics of complications. If operating with these prerequisites,

only horses otherwise healthy before treatment could be a part of the statistical material. This would

limit the usefulness of the results, as caecal decompression is not performed on perfectly healthy

horses with no signs of disease. Therefore this study operates with the “most reasonably explanation

of findings”, and thus similar prevalences of complications can be expected at other hospitals with

similar patient material and similar procedures as at LATH.

There are obvious biases in this study. It is likely that the amount of data recorded and decisions

made in a case varied with different clinicians, current workload at the hospital, severity of disease

and the emergency of the situation. Cases that were not exhibiting signs of colic when they arrived

58

were less likely to have the full range of diagnostic tests performed. Also, horses which died soon

after arrival are less likely to have exhaustive clinical records.

One problem with this study design is the lack of a control group. Scientifically, it would be very

interesting to compare two groups of horses with caecal tympany, where one group received caecal

decompression and a control group did not. This could reveal whether, or to which extent, caecal

decompression alone could cause complications. This could of course be problematic due to ethical

considerations.

The overall results were in line with the hypotheses stated and in line with the sparse information

about the effects and complications of caecal decompression, that were available in different

veterinary textbooks.

59

Conclusions Percutaneous caecal decompression was performed 186 times in 145 horses referred to LATH with

acute abdominal pain in the period 2006 to 2012, adding up to 1.26 caecal decompressions per

horse. Horses receiving caecal decompression at LATH included all genders and had a mean age of

8.9 years. The two most common breeds decompressed were Danish Warmblood and Icelandic

horse.

Caecal decompression is indicated in horses with caecal tympany. The procedure can be used to

reduce pain. This was proven by a significant decrease in heart rate after caecal decompression and

a significantly decreased need for strong analgesics. Furthermore, the procedure is effective at

facilitating a rectal examination and thereby improving diagnostic precision.

Clinical findings before caecal decompression included decreased or ceased borborygmia and steel

band sound in the right flank. Rectal examinations usually revealed a dilated caecum and abnormal

abdominal distension.

Proper aseptic and antiseptic techniques should be practised, such a the methods used at LATH.

Complications that could have been caused by caecal decompression were seen in 15.9% of horses

receiving caecal decompression. Fever, diarrhea and peritonitis were the most common

complications observed during hospitalisation. At long term follow up, complications were seen in

12.5% of the horses. Fever was the most common complication. No higher risk of euthanasia/death

could be linked to complications after caecal decompression.

No horse was declared dead due to caecal decompression or due to complications from caecal

decompression. No greater risks of complications or euthanasia were seen in horses receiving more

than one caecal decompression.

Decreases in pain score after caecal decompression were more common in horses that only needed

medical treatment, than in horses in need of surgical intervention. Horses diagnosed with caecal

tympany had significantly lower occurrence of relapse of pain than horses with other diagnoses, and

it took a significantly longer time from caecal decompression, until renewed administration of

analgesics.

60

Caecal decompression was useful in decreasing symptoms of caecal tympany and improving

clinical findings. Caecal decompression reduced the prevalence of steel band, reduced the number

of horses with abnormal abdominal distension and increased the number of horses with normal

rectal findings. Caecal decompression also decreased the respiratory rate of horses presented with

an increased respiratory rates before decompression.

In conclusion, the results of this study demonstrate that given the correct selection of patients and

while using suitable procedures, percutaneous caecal decompression is a simple, safe and effective

procedure, with benefits far outweighing any complications that can be reasonably anticipated.

Thus, it is a very suitable method for use in a modern veterinary hospital, as well as in the field.

Perspectives Comparing transrectal caecal decompression with percutaneous caecal decompression would be

very interesting. Sadly, so far, there is not much information available about the results from the

study of transrectal caecal decompression performed by Scotti et al. (2013).

The influence of antibiotics on the development of diarrhea after caecal decompression should be

investigated, in order to minimise this complication.

Induced caecal tympany treated with caecal decompression, in a more strict research environment

(GMP3 or GLP4

This study has proven that the positive effects of caecal decompression far outweigh the

complications, and the fear of using the procedure, in the veterinary community, seems to be

unfounded. The procedure should receive more attention than it does, for the benefit of patients,

veterinarians and owners alike.

approved facility) would also help to evaluate if complications were caused by

caecal decompression, or if they had other causes.

3 Good Manufacturing Practice 4 Good Laboratory Practice

61

References

Blood, D.C., Studdert, V.P. and Gay, C.C., 2007. Saunders Comprehensive Veterinary Dictionary. 3 edn. Saunders Elsevier.

Bouley, H.R., 1859. Recueil de médecine vétérinaire. Paris, France: l'École de Medicine: Renou et Maulde.

Brogniez, A.J., 1845. Traité de chirurgie vétérinaire : ouvrage contenant, comme accessoire, le résumé du cours de sidérotechnie vétérinaire, dont la première édition, publiée en 1835, est épuisée 3. 3. Bruxelles: Soc. Encyclographique des Sciences Médicales.

Christophersen, M.T., Dupont, N., Berg-Sørensen, K.S., Konnerup, C., Pihl, T.H. and Andersen, P.H., 2014. Short-term survival and mortality rates in a retrospective study of 1588 equine colic cases. Acta Scandinavia, Submitted.

Christophersen, M.T., Tnibar, A., Pihl, T.H., Andersen, P.H. and Ekstrøm, C.T., 2011. Sporting activity following colic surgery in horses: A retrospective study. Equine Veterinary Journal, 43, pp. 3-6.

Colahan, P.T, Mayhew, I.G, Meritt, A. and Moore, J., 1999. Normal values, inside jacket. Equine medicinand surgery. 5 edn. Mosby.

Dabareiner, R.M. & White, N.A, 1997. Diseases and surgery of the cecum. In: David, E., ed, Veterinary clinics of North America: Equine Practice. 2 edn. W.B. Saunders, pp. 303-315.

Dart, A.J., Dowling, B.A. and Hodgson, D.R., 1999. Caecal disease. Equine Veterinary Education, 11, pp. 182-188.

Dart, A.J, Hodgson, D.R. and Snyder, J.R., 1997. Caecal disease in equids. Australian Veterinary Journal, 75, pp. 552-557.

Davis, J.L., 2003. Treatment of peritonitis. Veterinary Clinics of North America: Equine Practice, 19, pp. 765-778.

Dyce, K.M., Sack, S.O. and Wensing, C.J.G., 2002. The Caecum. Textbook of Veterinary Anatomy. 3 edn. Elsevier, USA: Saunders, pp. 535-538.

Dyrendahl, I., 1995. Meddelande nr 33, Magnus Hjertebergs veterinärinstrument och 1813 år instrumentimport. Skara, Sweden: Veterinärhistoriska Muséet i Skara.

Edwards, R.B., 2002. Cecal diseases that can result in colic. In: Mair, T., Divers, T. and Ducharme, N., eds, Manual of Equine Gastroenterology. Kent, UK: W.B. Saunders, pp. 267-269.

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Fehr, J., 2012. Trocharization. In: Southwood, L.L., ed, Practical Guide to Equine Colic. Wiley-Blackwell, pp. 160-163.

Hackett, E., 2012. Trocharization. In: Southwood, L.L., ed, Practical Guide to Equine Colic. Wiley-Blackwell, p. 215.

Harlow, B.E., Laurie, L.M. and Michael, F.D., 2013. Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge. Veterinary Microbiology, 166, p. 225.

Hempel-Jørgensen, P., 1914. Bind II, Punktur af tarmen (Enterocentesis s. Punctio Intestini). Speciel Kirurgi, efter professor A.W. Mørkenbergs Forelæsninger. Copenhagen, Denmark, pp. 209-211.

Hesselholt, M., 1992. Tandlidelser, kolikdiagnostik og kirurgiske mave- tarmlidelser hos hest. Kirurgi I-III. Copenhagen, Denmark: Jordbrugsforlaget, p. 38.

Kalsbeek, H.C., 1969. Colic in the horse. Zaltbommel, Avanti.

Kaneene, J.B., Miller, R., Ross, W., Gallagher, K., Marteniuk, J. and Rook, J., 1997. Risk factors for colic in the Michigan (USA) equine population. Preventive Veterinary Medicine, 30, pp. 23-36.

Lowe, J.E., 1978. Xylazine, pentazocine, meperidine, and dipyrone for relief of balloon-induced equine colic: a double blind comparative evaluation. Journal Equine Medicine and Surgery, 2, pp. 286-291.

Mair, T., 2002. Clinical evaluation of the colic case. In: Mair T., Divers, T. and Ducharme, N., eds, Manual of Equine Gastroenterology. Kent, UK: W B Saunders, pp. 107-109.

McIlwraith, W.C, 1984. Equine digestive system. In: Jennings, P., ed, The Practice of Large Animal Surgery. W.B. Saunders Company, p. 632.

Mørkeberg, A.W., 1929. Hesten, Enterocentesis. Tapning for Vindkolik. Haandbog i Veterinærkirurgi Del 3. Frederiksberg, Danmark: Danmarks Veterinær og Jordbrugsbibliotek, pp. 265-270.

Pihl, T.H., 2013. Colic database, unpublished. Access database edn. Copenhagen, Denmark: University of Copenhagen, Large Animal Teaching Hospital.

Reeves, M.J., Curtis, C.R., Salman, M.D. and Hilbert, B.J., 1989. Prognosis in equine colic patients using multivariable analysis. Canadian Journal of Veterinary Research, 53, p. 87.

Roelvink, M.E.J., Goossens, L., Kalsbeek, H.C. and Wensing, T., 1991. Analgesic and spasmolytic effects of dipyrone, hyoscine-N-butylbromide and a combination of the two in ponies. Veterinary Record, 129, pp. 378-380.

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Ross, M., 1999. Diseases of the Caecum. In: Colahan, P.T, Mayhew, I.G., Meritt, A.M. and Moore, J.N., eds, Equine Medicine and Surgery. 5 edn. Mosby, pp. 739.

Schaller, O., ed, 2007. Illustrated Veterinary Anatomical Nomenclature. 2 edn. Stuttgart, Germany: Enke.

Scotti, G.B., Lazzaretti, S.S., Zani, D.D. and Magri, M., 2013. Transrectal decompression as a new approach for treatment of large intestinal tympany in horses with colic: Preliminary results. Equine Veterinary Education, 25, pp. 184-188.

Smedegaard, H.H., 2013. Personal communication. Veterinærhistorisk Museum, KU, Frederiksberg, Denmark. E-mail: [email protected]

Stewart, A., 2010. Intestinal diseases in horses and foals. In: Kahn, C. and Line, S., eds, The Merck Veterinary Manual. 10 edn. Merck & Co., Inc., pp. 258.

Thoefner, M.B., Ersbøll, B.K., Jansson, N. and Hesselholt, M., 2003. Diagnostic decision rule for support in clinical assessment of the need for surgical intervention in horses with acute abdominal pain. Canadian Journal of Veterinary Research, 67, pp. 20-29.

Thoefner, M., Ersbøll, B., Hesselholt, M., 2000. Predicting the Need for Immediate Surgical Intervention in Horses with Acute Abdominal Pain. In: Thoefner, M., Case selection in the equine acute abdomen. Copenhagen, Denmark: Department of Clinical Studies, The Royal Veterinary and Agricultural University.

Tinker, M.K., White, N.A., Lessard, P., Thatcher, C.D., Pelzer, K.D., Davis, B. and Carmel, D.K., 1997. Prospective study of equine colic incidence and mortality. Equine Veterinary Journal, 29, pp. 448-453.

Van Galen, G. and Pihl, T.H., 2013. Correspondence. Equine Veterinary Education, 25, pp. 483-484.

Van Harreveld, P.D. and Gaughan, E.M., 2002. Physical evaluation of the colic horse. In: T. Mair, T. Divers and N. Ducharme, eds, Manual of Equine Gastroenterology. Kent, UK: W B Saunders, pp. 109-112.

White, N.A., 2006. Equine Colic: V. Treatments for Colic. 52 Annual Convention of the American Association of Equine Practitioners - AAEP, 2006, 2006, Ithaca: International Veterinary Information Service (www.ivis.org),

White, N.A., 1990b. Epidemiology and ethology of colic. In: Cann, C.C. and Lazar,T., eds, The Equine Acute Abdomen. Philadelphia, USA: Lea & Fabiger, pp. 49-65.

2006; Document No. P5322.1206., pp. 153-155.

White, N.A., 1990a. Diseases of the Cecum. In: Cann, C.C. and Lazar,T., eds, The Equine Acute Abdomen. Philadelphia, USA: Lea & Fabiger, pp. 369-370.

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Wilkins, P., 2010. Trocarization. In: Kahn, C. and Line, S., eds, The Merck Veterinary Manual. 10 edn. Whitehouse station, N.J. USA: Merck & Co, Inc., p. 1569.

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I

Ylva Winsborg

Ylva Winsborg

Appendix 1

Ylva Winsborg

Ylva Winsborg

Ylva Winsborg

II

Ylva Winsborg

Ylva Winsborg

Appendix 2

Ylva Winsborg

Ylva Winsborg

Ylva Winsborg

Ylva Winsborg

I N S T I T U T F O R P R O D U K T I O N S D Y R O G H E S T E

K Ø B E N H AV N S U N I V E R S I T E T

10. MAJ 2013

Kære hesteejer

Jeg er dyrlægestuderende og nu i gang med min afsluttende specialeopgave.

I forbindelse med dette har jeg brug for din hjælp til at svare på nogle

spørgsmål. Mit speciale handler om kolikheste og hvordan det går for dem,

efter at de er blevet hjemsendt fra Universitetshospitalet i Taastrup. Mere

viden omkring kolik og behandling af kolikheste vil kunne hjælpe både

heste, hesteejere og dyrlæger i fremtiden. Derfor ville jeg sætte stor pris på

din besvarelse. Alle informationer vil forblive anonyme og vil kun blive

brugt til forskning.

Da din hest har været indlagt her vil jeg bede dig om at gå ind og besvare et

spørgeskema. Det tager kun 5 minutter og er en meget vigtig del i

forskningen omkring behandling af og helbred hos kolikheste.

Spørgeskemaet kan besvares over din computer/smartphone gennem at

indtaste dette link i din browser:5

https://survey.enalyzer.com/?pid=h2h8g3dn

Du skal angive din hests navn: ___________________________

Og journalnummer:____________________________________

Hvis du hellere vil have tilsendt en papirudgave af spørgeskemaet, må du

gerne kontakte mig på min email-adresse [email protected] . Jeg har

desværre ikke mulighed for at svare på spørgsmål omkring din hest eller den

behandling din hest har modtaget.

Venlig hilsen

Ylva Winsborg

BSc.med.vet, Speciale studerende

III

mailto:[email protected]

Ylva Winsborg

Ylva Winsborg

Ylva Winsborg

Appendix 3

Helbred hos kolikheste

Som en del i mit afsluttende Specialeprojekt på dyrlægeuddannelsen ved Københavns Universitet har jeg brug for din hjælp. Derfor er jeg meget glad for at du har valgt at svare på dette spørgeskema. Det foregår helt anonymt. Besvarelserne vil blive brugt til forskning der kan hjælpe andre heste med kolik til en endnu bedre behandling.

Venlig hilsen Ylva Winsborg BSc.med.vet

1. Angiv din hests navn.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

2. Angiv din hests journalnummer.

Journalnummeret fremgår af det brev du har modtaget vedrørende undersøgelsen.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

3. Lever din hest stadig?

(Angiv kun ét svar)

Ja

Nej

Jeg har solgt den

4. Hvis din hest er død, var dødsårsagen relateret til at hesten havde kolik?

Svar kun hvis din hest er død, ellers gå videre.


Ja, aflivningen var relateret til kollik

Nej, aflivningen var ikke rellateret til kollik

Ved ikke

IV

Ylva Winsborg

Ylva Winsborg

Appendix 4

Ylva Winsborg

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

5. Hvis din hest er død:

Hvornår blev den aflivet (Ca dato)?Hvorfor blev den aflivet?

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

6. Har din hest haft kollik igen efter indlæggelsen?


Nej

En enkelt gang

Flere gange

7. Hvordan helede operationssåret?(Du kan sætte kyds flere steder)

(Angiv gerne flere svar)

Hesten blev ikke opereret

Uden problemer

Der var flåd fra såret

Der var hævelse omkring såret

Der var ømhed omkring såret

Der opstod brok

8. Hvordan helede trokariseringsstedet?(Det lille indstik i hestens højre flanke)(Flere alternativer er mulige)

V

Ylva Winsborg


Hesten blev ikke trokariseret

Uden problemer

Der var flåd fra såret

Der var hævelse omkring såret

Der var ømhed omkring såret

9. Har der været andre komplikationer efter at hesten kom hjem fra hospitalet? (Du kan sætte kryds flere steder).


Ingen

Hathed

Betændelse i blodkar

Forfangenhed

Diarre

Nedsat ædelyst

Mavesår

Feber

10. Har din hest haft nogen betændelse/pus/bylder efter at den kom hjem?(Du kan sætte kryds flere steder, hvis din hest har haft betændelse/pus/bylder mere end et sted.)


Nej

Ja, på hals/hoved

Ja, på benene

Ja, på siden af maven/bugen

Ja, under maven

Ja, på bagparten

VI

Ylva Winsborg

Ylva Winsborg

11. Hvis en af dine heste igen fik alvorlig kolik, ville du så vælge at få den opereret?


Ja

Ja, men kun hvis forsikringen dækker det.

Nej

Måske

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

12. Hvad brugte du din hest til før indlæggelsen?


Trav

Gallop

Dressur

Spring

Kørsel

Western

Gangartsridning (Islandsheste)

Skovture/hygge

Avl

13. Hvilket niveau blev hesten brugt på inden indlæggelsen?


Blev ikke brugt

Lavt

VII

Medium

Højt

14. På hvilket niveau blev hesten brugt efter indlæggelsen?


Mindre/Lavere niveau end før

Det samme som før

Højere/bedre end før

15. Er der blevet foretaget nogle ændringer i stalden efter at din hest kom hjem? (Flere alternativer er mulige)


Nej

Ændringer i fodring

Ændringer i motion

Ændringer i behandling/forebygese af orm.

Ændringer i tandraspning

Andre ændringer

16. Har du andre kommentarer vedrørende din hests trivsel efter indlæggelsen?

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_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Tak for din besvarelse!

Husk at trykke "End survey"/ pil til højre for at afslutte!

VIII

Documents

Caecal decompression in the horse · My first recollections of caecal decompression from the Large Animal Teaching hospital was a sentence from an American professor in internal medicine