From Dog
Macroscopic appearance of cystic endometrial hyperplasia in a dog[1]

Endometritis is an inflammatory disease of the canine uterus that commonly leads to infertility and pyometra[2] formation.

The majority of canine cases of endometritis are of bacterial origin (usually Escherichia coli, Streptococcus spp[3]), with a small representation of Mycoplasma spp and fungi involved in more rare cases[4].

Chronic inflammation may perpetuate existing disease and invariably results in loss of estrogen receptors[5].

Endometritis is also concurrently associated with

More rarer conditions associated with this disorder include:

The distinction between cystic endometrial hyperplasia, pyometra and endometritis is based on the stage of the reproductive cycle. Endometritis is a uterine infection that develops postpartum, when serum progesterone levels are low. In contrast, pyometra usually develops during diestrus, when progesterone levels are high.

Affected dogs may show hematuria, dysuria and blood tests may reveal leucocytosis, but these are not consistent findings in all dogs.

Diagnosis of endometritis and be made presumptively from ultrasonography, but definitive diagnosis requires transcervical uterine cannulation and histological examination of biopsied tissue samples obtained via cannulation or laparoscopy[10].

Treatment of endometritis usually requires a prolonged course of antimicrobial therapy (e.g. amoxycillin/clavulanate, enrofloxacin or gentamycin), based on culture and sensitivity of the uterus.

Intravaginal pessaries containing misoprostol have also been shown to be effective at inducing uterine involution[11].

Long-term complications of endometritis include anestrus, recurrence of endometritis, infertility and abortion[12].


  1. Penn Veterinary Medicine
  2. Smith FO (2006) Canine pyometra. Theriogenology 66(3):610-612
  3. Schoon HA et al (1992) The pathogenesis of the "endometritis-pyometra complex" in the female dog. Zentralbl Veterinarmed A 39(1):43-56
  4. Fontaine E et al (2009) Diagnosis of endometritis in the bitch: a new approach. Reprod Domest Anim 44(2):196-199
  5. De Cock H et al (1997) Immunohistochemical analysis of estrogen receptors in cystic-endometritis-pyometra complex in the bitch. Theriogenology 48(6):1035-1047
  6. Günzel-Apel AR et al (2008) Prolonged foetal retention in a bitch resulting in trichogranulomatuous panmetritis and re-establishment of fertility after unilateral ovariohysterectomy. Reprod Domest Anim 43(1):117-120
  7. England GC et al (2012) Delayed uterine fluid clearance and reduced uterine perfusion in bitches with endometrial hyperplasia and clinical management with postmating antibiotic. Theriogenology 78(7):1611-1617
  8. Kim KS & Kim O (2005) Cystic endometrial hyperplasia and endometritis in a dog following prolonged treatment of medroxyprogesterone acetate. J Vet Sci 6(1):81-82
  9. Schlafer DH et al (2012) Diseases of the canine uterus. Reprod Domest Anim 47(6):318-322
  10. Watts JR et al (1997) New techniques using transcervical uterine cannulation for the diagnosis of uterine disorders in bitches. J Reprod Fertil Suppl 51:283-293
  11. Gábor G et al (1999) Intravaginal prostaglandin F2 alpha for the treatment of metritis and pyometra in the bitch. Acta Vet Hung 47(1):103-108
  12. Gilbert RO et al (1989) A retrospective study of 40 cases of canine pyometra-metritis treated with prostaglandin F-2 alpha and broad-spectrum antibacterial drugs. J Reprod Fertil Suppl 39:225-229