Thorax (1967), 22,466.

Congenital oesophageal achalasia in the dogR I C H A R D J . E A R L A M , P A U L E . Z O L L M A N , A N D

F . H E N R Y E L L I S , J R .

From the Mayo Graduate School of Medicine {University of Minnesota), and the Sections of VeterinaryMedicine and Surgery, Mayo Clinic and Mayo Foundation, Rochester, Minnesota, U.S.A.

A 3-month-old German shepherd puppy with a congenitally dilated oesophagus had radiographic,cinefluoroscopic, and oesophageal motility studies before a modified Heller operation wasperformed. Subsequent examination of the oesophagus revealed no ganglion cells, and thecondition was considered to be identical with human achalasia. In dogs, this appears to be morecommon in the German shepherd breed.

In achalasia of the oesophagus the body of theoesophagus lacks peristalsis, and is usually dilatedwhile the lower sphincter fails to respond normallyto swallowing. Pressure records from the oeso-phagus rarely show an increase in the resting pres-sure of the lower sphincter. The term 'cardio-spasm', which implies increased pressure, is notso acceptable as achalasia, which describes afailure of the sphincter to relax and contract in aco-ordinated manner. This inco-ordination isrelated to loss of the enteric neurons or ganglioncells in Auerbach's myenteric plexus. The absenceor reduction in number of these nerve cells is acommon finding in this disease and occurs mainlyin the body of the oesophagus, but may affect thelower sphincter and the body in varying propor-tions. The aetiology of the loss of enteric neuronsis unknown. For this reason it is desirable toaccumulate as much information about the epi-demiology of the disease as possible in the hopethat a common aetiological factor may emerge.Dogs with an enlarged oesophagus have been de-scribed before, but this is the first occasion onwhich cinefluoroscopy, oesophageal pressurestudies, and histological examination have beenperformed in sufficient detail for it to be saidthat achalasia of the oesophagus definitely canoccur in dogs. A German shepherd dog (the termused in North America to describe an Alsatian)with achalasia is presented, and 43 other casesdescribed in the literature are discussed.

CASE REPORT

A German shepherd puppy, 3 months old, was studiedbecause she failed to eat a normal diet and after each

meal vomited undigested a large bolus of food. Shewas one of a litter of seven and differed in no wayfrom her littermates until weaned, after which shedid not gain weight satisfactorily and, when first seen,weighed 8-4 kg. Both the sire and the dam werenormal and had previously had normal litters.

Fluoroscopy showed a grossly enlarged oesophagus(Fig. 1) with a few peristaltic contractions in thedilated region which progressed distally along thewall of the oesophagus without actually occludingthe dilated chamber. During fluoroscopy, which lasted10 minutes, the sphincter was seen to relax onlythree times.

Oesophageal motility studies were performed asoriginally described by Schlegel and Code (1958).Four small polyethylene tubes were tied together andpassed down the oesophagus. The lumen of one tubecontained wire that prevented any acute bends.Another tube was covered at its distal end by a smallwater-filled balloon. The remaining two water-filledtubes had lateral openings at 5 and 10 cm. proximalto the balloon. Simultaneous pressures were recordedfrom the balloon and the two open-tip tubes atdifferent levels in the oesophagus. The recordingsrevealed a few simultaneous pressure humps afterswallowing in the body of the oesophagus (Fig. 2). Butthe sphincter, which had a normal pressure profile,relaxed poorly and infrequently. When there wasrelaxation, it was incomplete because a prematurecontraction cut it short. These findings closely corre-lated with those seen on cinefluoroscopy. They werealso similar to the recordings made in humans.

A modified Heller operation was performed whenthe dog was 3^ months old. Under ether anaesthesia,with controlled respiration and a cuffed endotrachsaltube, the thorax was opened through the left eighthintercostal space. Patches of pneumonia were dis-covered in the upper and middle lobes on this side.The oesophagus was dilated as far as it could betraced under the hilum of the left lung, but there was

466

Congenital oesophageal achalasia in the dog 467

FIG. 1. Oesophageal radiograph after barium swallowshows dilated oesophagus in which barium is surroundedby non-opaque fluid. Some radiopaque material has passedinto the stomach.

a normal-sized portion in the region of the hiatus ofthe diaphragm. The lower end was mobilized with-out penetrating the thin mediastinum, and myotomywas performed extending from the gastro-oesophagealjunction toward the dilated portion for 5 cm., thephreno-oesophageal ligament being undisturbed. Themyotomy incision was placed anterolaterally betweenthe anterior and posterior vagi and the mucosa wasseparated from muscle for about half its circum-ference so that mucosa pouted through and preventedthe muscle from uniting again across the incision.

During the next two days the puppy was fed inthe upright position with a mixture of milk andwater. Whereas formerly the fluid did not pass intothe stomach, it was now heard to gurgle into thestomach after swallowing. However, on the third post-operative day the dog succumbed with a respiratoryinfection which could not be controlled with anti-biotics.

Necropsy confirmed that the immediate cause ofdeath was a pulmonary infection affecting the wholeof both lungs except the left lower lobe. The cause ofthis was not determined, but distemper was excludedbecause the puppy had been inoculated and no inclu-sion bodies were discovered in histological sections ofthe lung. The infection could have been secondaryto aspiration of food and was exacerbated by theanaesthesia.

The oesophagus (Fig. 3) was thin and dilatedthroughout its whole length, and, when filled withwater, the water passed readily through the lowersphincter from both directions, thus excluding astricture. The oesophagus was 27 cm. long, itsmaximal circumference was 13-5 cm., and the musclecoat was approximately 1-5 mm. thick. The nervesupply and the arterial blood supply were macro-

Lower Mid Upper

FIG. 2. Tracings of intraluminal pressures in the lower, middle, and upper parts of the oesophagus showingfeeble contractions and lack of peristalsis in the body of the oesophagus and weak contraction at the sphincter.

468 Richard J. Earlam, Paul E. Zollman, and F. Henry Ellis, Jr.

FIG. 3. Necropsy specimen of oesophagus showing collapsed thin walls.

scopically normal; the salivary glands were of theusual size, and no large vascular anomaly waspresent.

Histological examination revealed no ganglion cellsin Auerbach's plexus between the muscle layers ofthe oesophagus (Fig. 4) as compared with normal(Fig. 5). The stomach, small intestine, colon, andtrachea all contained normal ganglion cells.

DISCUSSION

The term 'dilated oesophagus' is not sufficientlyexact to describe anything more than an enlargedoesophagus. In dogs, the condition may be dueto achalasia or to a vascular ring anomaly. Stric-tures secondary to trauma, tumours, parasites, orforeign bodies can be differentiated, but an oeso-phagus enlarged from compression by an arterialring has frequently been reported as a dilatedoesophagus. If the oesophagus is constricted by avascular ring, the obstruction is usually in theupper part, the dilatation having the appearanceof a diverticulum in the upper part of the thorax,which is larger than in achalasia, while the distalpart of the oesophagus and its lower sphincter arenormal (Milks and Williams, 1935 ; Detweiler andAllam, 1955 ; Lawson, Penhale, and Smith, 1957).

Dilatation of the oesophagus may occur in thehorse (Hutyra, Marek, and Manninger, 1938), butidiopathic hypertrophy is more common and hasbeen described in horses, foals, and a hinny(Hayes, 1908 ; Joest, 1926; Nieberle and Cohrs,1931 ; Djukic and Oreskovic, 1959 ; Wejda, 1961 ;Guarda, 1962). One of us (P. E. Z.) has seen adilated oesophagus in a rabbit, but since theobstruction was in the mid-thoracic region thisprobably represented a vascular anomaly.

Forty-four cases of oesophageal dilatation inthe dog have now been reported, and possibleexamples of a vascular anomaly have been ex-

cluded in the Table. In the majority of cases thereis not enough clinical or pathological informationto justify their being grouped together under anyother title than that of dilated oesophagus.

The hereditary and familial aspects are interest-ing because in dogs there are breed differences.German shepherd dogs form the largest singlegroup. The six greyhounds described by Spy(1963) may have had a vitamin deficiency andare therefore not significant. Lacroix (1949) statedthat the breeder whose Great Dane sired the puppyhe described said that other offspring had had asimilar condition over the past six years, butgives no further details. Brasmer (1953) describesthree German shepherd dogs, of which three hadthe same sire and two the same dam, but the pre-vious 12 litters had been normal. It may be rele-vant that the two dams had in common an inter-national champion great-grandfather. Breshears(1965) found three, of which one is still alive, ina litter of eight German shepherd dogs. Morganand Lumb (1964) treated a German shepherd suc-cessfully, and this dam later produced a normallitter. The present puppy had normal parents asdemonstrated by oesophageal motility and fluoro-scopy, and in a well-studied family tree there wereno others affected.

The geographical distribution tends to suggestthat this is a spontaneously occurring congenitalcondition rather than one caused by infection withbacteria, viruses, or parasites such as Trypanosomacruzi, the cause of Chagas' disease, that are them-selves associated with the climate. The majorityare from North America, but occasional casesoccur in European countries, Australia, and SouthAfrica. It is curious that none has been describedin England, France, or Alsace, the country oforigin of German shepherd dogs.

The age at presentation is usually after wean-ing. Prior to this, the intake of food is small

Congenital oesophageal achalasia in the dog 469

FIG. 4. (a) Section through bodyof oesophagus of dog withachalasia. Haematoxylin andeosin. x 65.

FIG. 4. (b) Intel-muscular layershown in the area marked con-tained blood vessels, nervefibres, and fibroblasts, but noganglion cells. Haematoxylinand eosin. x 190.

quantities of milk, and it is only with the ingestionof larger quantities of solid food that symptomsoccur. The oldest dog reported as having the con-dition described was a German shepherd, 11 yearsold, on which a modified Heller operation wasperformed by Teunissen (1957). This appears tobe a genuine case, but may possibly have beencongenital because the duration of symptoms wassaid to be months.

Vomiting of an undigested bolus of foodcovered with saliva and mucus is the usual pre-sentation. This may occur at any interval aftereating ; it may depend on the activity of the dog,

2P

but usually occurs within two hours. The doglowers its head and painlessly regurgitates withoutany effort. In spite of a good appetite, the animalfails to gain weight satisfactorily.

De Jong (1935) and Morgan and Lumb (1964)both described how the dilated oesophagus can befelt on the left side of the neck, and when theswelling is palpated, gurgling can be heard. Thisdid not occur in our experience. If pressure onthe stomach can induce reflux, the diagnosis ofa dilated oesophagus similar to that in achalasiain the human must not be made. Oesophago-scopy has been performed on a dilated oeso-

470 Richard J. Earlam, Paul E. Zollman, and F. Henry Ellis, Jr.

FIG. 5. (a) Section throughmiddle of oesophagus of nor-mal dog. Haematoxylin andeosin. x30.

FIG. 5. (b) Enlargement centredon Auerbach's plexus. Haema-toxylin and eosin. x 100.

phagus by Stack, Thomson, and Suyama (1957),Knecht and Eaddy (1959), Reed, Archibald, andCawley (1960), and Morgan and Lumb (1964).They demonstrated a large oesophagus partiallyfilled with food, saliva, and mucus. Ulcerationand haemorrhage from the mucosa may be seen.The animal had to be anaesthetized for this pro-cedure, and the oesophagoscope passed easily intothe stomach. However, it is to be noted that easypassage of the sphincter with sounds, bougies, oran oesophagoscope is possible whether the animalis anaesthetized or not, so that a stomach tube canbe used for intragastric feeding. If the radio-graphic technique is satisfactory, there appears

to be no advantage in performing oeophagoscopy,which carries the risk of anaesthesia with it.

The typical macroscopic pathology is demon-strated in this puppy. The oesophagus is convertedinto a thin-walled atonic sac extending from thediaphragm to the superior sphincter. It is essentialat necropsy to reconfirm the easy passage of fluidthrough the lower sphincter and thereby excludeany anatomical obstruction.

Histological examination in our case revealednormal muscle in the relatively thinned musclelayers. There was little intermuscular tissue, andno sign of ganglion cells was seen on serialsections.

Congenital oesophageal achalasia in the dog 471

T A B L E

REPORTS OF OESOPHAGEAL ACHALASIA IN DOGS

Author

Schlotthauer . .De Jong

Lacroix, J. V.NewcombSchnelle

Lacroix, L. J.

Brasmer

Hofmeyr

Teunissen

Stack et alMichaelGoodloe and Schichor/. Amer. vet. med. Ass.NiisselKnecht and Eaddy . .

Reed et al.

PattersonSmith and JonesPoppel and LustKitchen et al.SpyMaksic and Small . .Morgan and Lumb . .Breshears

This paper

Year

19291935

194019411945

1949

1953

1956

1957

195719571957195819591959

1960

19611961196219631963196419641965

1966

Breed Sex

Boston terrierGordon setterAiredale terrierGerman shepherdGreyhoundDalmatianBoston terrierFox terrierFox terrierSpringer spanielBoston terrierGreat daneDachshundDachshundGerman shepherdGerman shepherdGerman shepherdRidgeback (S.A.

breed of Dober-mann Pinscher)

German shepherdSpaniel mongrelGerman shepherdGerman shepherdManchesterGerman shepherdSpanielMiniature

SchnauzerSalukiFox terrierChihuahuaCollieDachshundDachshundGreyhound x 6German shepherdGerman shepherd

M—

FF

.—M——

——

MFMF

——FMM

Age

8 mo.3 mo.6 wk

10 wk4 mo.

10 mo.4 mo.5 mo.6 mo.7 mo.8 mo.5 mo.3 mo.3 mo.6 wk4 wk7 wk4 yr

Origin Therapy

Rochester, Minn. , U.S.A.Hilversum, Holland Small meals

AtropineEvanston, 111., U.S.A. Atropine, dieU.Sydney, AustraliaIllinois, U.S.A.

Sydney, Australia

Brewer's yeastVitamins A, B, D

. .——

—

Adiphenine

Illinois, U.S.A.

South Africa

11 yr4 mo.8 mo.

Switzerland

Adiphenine———

Heller's operation

Heller's operationHeller's operation

Syracuse, N.Y., U.S.A. Bouginage10 wk Pennsylvania, U.S.A.7 wk Nebraska, U.S.A.

— ! 10 wk Miami, Fla., U.S.A.M 5 wk Hannover, GermanyM > 3 mo.

—

——. .

—• —F

German shepherd MGerman shepherd MGerman shepherdGerman shepherd

MF

3 vr5 wk

Pittsburgh, Penn., U.S. A.

Ontario, Canada

Colorado, U.S.A.9 mo. North America—

S y r4 mo.8 wk6 wk2 mo.2 mo.Alive3 mo.

New York, U.S.A.Newcastle, Penn., U.S.A.ScotlandIllinois, U.S.A.

—.

—.Gastrotomy, bouginage

Heller's operationHeller's operation

__.

_

Colorado. U.S.A. Died, fed standingPine Bluff, Ark., U.S.A.

.i No treatment

Rochester, Minn., U.S.A. Heller's operation

Cure

NoNoYes—YesYes—————YesYes—

—__

Yes

YesYesYes————Yes

YesYes

.__

———Yes

—Yes—

As a result of our own experience we suggestthat the best treatment for a dog with achalasiais to feed fluids two or three times each day withthe dog in a vertical position ; if this fails, astomach tube may be passed for intragastric feed-ing. This would enable the dog to regain its weightand develop immunity to infection. The evidencesuggests that this might even enable the animalto pass through the critical stage following wean-ing, and if, after a few months, no further progresshas been made, a modified Heller procedure mightbe done. If the animal is fit when first seen, itmay be possible to proceed with an operationimmediately.

Our thanks are due to Dr. and Mrs. J. H. Grindlayfor kindly allowing examination of the puppy, itssire, and dam ; to Dr. C. F. Code for help in analysingthe motility records and fluoroscopy ; and to J. F.Schlegel and Delbert Minske for technical assistance.

This investigation was supported in part byResearch Grant AM-5457 from the National Institutesof Health, Public Health Service.

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