Canine PyometraCanine Pyometra

Vivek JoshiPh.D Scholar

Division of Medicine

OverviewOverview1. Introduction2. Types3. Predisposing Factors4. Aetio-pathogenesis5. Clinical signs6. Diagnosis7. Differential diagnosis8. Treatment9. Control10. Conclusion

IntroductionIntroduction

Canine pyometra → intact bitches → uterine bacterial infection → systemic illness

Etiology: Escherichia coli clones from normal flora

Early diagnosis & intervention to avoid disastrous consequences

Closed-cervix pyometra : medical emergency

PyometraPyometra

Greek: pyo = pus, metra = uterus

Accumulation of pus in uterus

Infection overlying CEH → intrauterine purlent fluid

Diestrual disorder of intact adult bitches (Dow, 1959) Chronic purulent endometritis post estrum, with/ without multisystemic effects (Hardy & Osborne, 1974)

CEH-Pyometra-ComplexCEH-Pyometra-Complex

Cystic endometrial hyperplasia

Endometritis Pyometra

cysts 1 mm-1or more cm

uterine intraluminal diameter of< 1 cm

uterine intraluminaldiameter of> 1 cm

CEH-Pyometra-ComplexCEH-Pyometra-Complex CEH precedes pyometra

CEH & pyometra → two separate entities → clinical manifestations & morphohistological differences

(De Bosschere et al, 2001)

Four gradations of CEH-Pyometra complex(Dow, 1959)

Type I Type II Type III Type IV

thickened endometrium with translucent cysts

diffuse plasma cell infiltration

acute endometritismetritis or pyometra

Chronic endometritis, squamous metaplasia

““Open” or “Closed” cervixOpen” or “Closed” cervix

1. Closed pyometra

2. Open pyometra

3. Stump pyometra inflammation/ bacterial infection→uterine body

remnant

Severity of signs : cervix patency

INCIDENCEINCIDENCE

Pyometra : 23-24% before 10 yrs(Egenvall et al, 1999)

(Tamilnadu J. Veterinary & Animal Sciences 7 (5) 252-253, September-October, 2011)

Predisposing FactorsPredisposing Factors

Age middle-aged or old bitches (> 4 years) 8.2 years (Dow, 1959) 2.4 years (Kersey, 2004)

Parity nulliparous, intact bitches

Oestrous characteristics long diestrus

Breed wire-haired Dachshund/ Mongrels: ↓ risk

Rottweiler, rough-haired Collie,Cavalier King Charles Spaniel/ Golden Retriever: ↑ risk

(Susi Arnold, 2006)

No breed influence on pyometra development(Niskanen & Thrusfield, 1998)

PathogenesisPathogenesis

1) Hormonal influence on uterus2) Virulence of infecting bacteria3) Ability of bitch to combat infection 4) Individual sensitivity

Growth factors & their receptors (growth factors receptors, GFs)

(Gama et al. 2009)

Hormonal influence on uterusHormonal influence on uterus

Progesterone in aetiology of canine pyometra & its potentiation by estrogen

Teunissen (1952)

Prolonged stimulation of uterus by progesterone from cystic corpora lutea

Hardy & Osborne (1974)

Steroid hormones influence conc. & distribution of steriod receptors in uterus & cause pyometra

Dhaliwal et al (1999)

Virulence of infecting bacteriaVirulence of infecting bacteria

Bacterial infection- not primary cause

Predominant bacteria (in 82–100% of clinical cases): Escherichia coli

E. coli isolates → O serogroups (O4, O6)(Wadas et al, 1996)

Uropathogenic virulence factors (UVFs) for extra-intestinal infection

(Yuri et al, 1999)  

Genes Products

pap P fimbriae

fim Type1 fimbriae

sfa S fimbriae

hlyA α-haemolysin

cnf1 cytotoxic necrotising factor 1

iuc aerobactin

afa afimbrial adhesin 1 or Afa1

P fimbriae PapGIII adhesin binds to Galα1–4Gal glycolipids &

Forssman Ag

bacterial adhesion & colonization

α-haemolysin/ CNF1 : tissue damage

E. coli isolates : 5, 3 or more UVF genes

genetic linkage- UVF genes & pathogenicity associated islands (PAIs) : cnf1, hlyA; hlyA, pap; cnf1, hlyA, papGIII

Clinical signs Open-cervix Close-cervix

Vaginal discharge Watery- creamy;light brown, green or yellow

rare

Temperature normal/ slightly elevated

elevated/ sub-normal (toxemic bitch)

Lethargy/ depression + +

Vomiting + +

Polyuria/ polydipsia + +

Clinical signs : 4-8 wks following last standing heat

Diestrus bitch with purulent vaginal dischargeDiestrus bitch with purulent vaginal discharge

Mechanism of PolyuriaMechanism of Polyuria

Multifactorial

Reduced permeability for water in DCT of kidney(Asheim, 1964)

Deposition of immune complexes in glomeruli causes membranoproliferative glomerulonephropathy

(Sandholm et al, 1975)

Renal tubular insensitivity to ADH due to tubular damage by E.coli endotoxins

Abdominal palpationAbdominal palpation

Open-cervix pyometra thickened, irregular & slightly turgid uterine horns

Closed-cervix pyometra greater degree of uterine distension visible abdominal enlargement

Care taken to avoid rupturing a distended uterus

UltrasonographyUltrasonography

In early diagnosis of canine pyometra(Bigliardi et al; 2004)

Most valuable in closed-cervix pyometra

Uterine wall- increased thickness/ hypoechoic Uterine lumen- grossly dilated/ anechoic fluid with small echogenic particles

RadiographyRadiography

Abdominal Radiography tubular structures of fluid density/ opacity in caudal abdomen

Not specific for pyometra

Clinical pathologyClinical pathology

Haematology not pathognomic for pyometra

Leukocytosis TLC : 15,000- 60,000/mm³

(Bigliardi & Pamigiani, 2004) Neutrophilia (degenerative left shift) : PBN >3%

Anemia Normocytic, normochromic, non-regenerative

Hyperglobulinemia

Hypoalbuminemia

↑ ALP, BUN

↑ PG-metabolite (SIRS); cTnI / CRP (myocardial injury→ endotoxemia, septicemia, DIC, secondary uremia)

(Hagman et al, 2007) Urinalysis Hyposthenuria (sp. gravity < 1.030)

TreatmentTreatment

Surgical Ovariohysterectomy is treatment of choice

severely ill bitches : aggressive fluid therapy & broad spectrum antibiotics

Transcervical Endoscopic Catheterisation (TECT)(Verstegen et al., 2008)

MedicalMedical

Indications: further breeding

O.H. not possible : intercurrent disease (CHF)

owner refuses surgery

1. Antibiotics1. Antibiotics in every case G(-) and G(+) efficacy according resistogram as soon as possible

Quinolones (Enrofloxacin/Marbofloxacin) Gentamicin Cefalosporins

Natural PGF₂α Synthetic PGF₂α

0.02 mg/kg SC bid 7-10 days 0.001– 0.002 mg/kg SC OD 7-10 days

Day 1 : 0.1 mg/kgDay 2 : 0.2 mg/kgDay 3-7 : 0.25 mg/kg OD

Longer duration of action

Dinoprost(Lutalyse®)

Cloprostenol(Cyclix®)

2. Prostaglandin F₂α/ PGE

Aglepristone 10 mg/kg SC

day 1, day 2, day 7

once a week

3. Antiprogestins

4. Antiprolactins4. Antiprolactins

Cabergoline (Cabgolin®) 0.005 mg/kg PO OD 7-10 days

5. Supportive therapy5. Supportive therapy

IV fluids (Lactated Ringer’s sol. /Glucose 5%) H₂ blocker : Metoclopramide (vomiting / nausea) NSAIDs Antihistaminics Anticholinergics (excess salivation)

Prostaglandins Results

Open-Cervix Pyometra

Closed-Cervix Pyometra

Complete resolution

94 % 31 %

Whelped litter 88 % -

Recurrence 26- 40 % within 1 year

(Feldman & Nelson: Canine and Feline Endocrinology and Reproduction, 2004)

ControlControl

1. O.H. at 6 months of age or before after breeding years

2. Post-partum reproductive system checking

3. Very rarely use contraceptive drugs

ConclusionConclusion

Canine pyometra : infectious cause of infertility

Occurrence : any bitch → clinical signs → after diestrus regardless of age

Confirmatory diagnosis : combination of diagnostics

OH : therapy of choice

PGF₂α therapy : ↑ success rates in open-cervix pyometra