Introduction

• Cause: usually develops within 1 week of whelping (also abortion, mating, artificial insemination (AI) or normal estrus).
• Signs: vaginal discharge: sanguinous to purulent.
• Diagnosis: signs, imaging.
• Treatment: broad-spectrum antibiotics, supportive, follow-up hysterectomy.
• Prognosis: guarded depending on condition of bitch, potentially fatal if uterus ruptures.

Pathogenesis

Etiology

• Usually ascending bacterial infection: gram-negative, eg E. coli, Staphylococcus spp, Streptococcus spp and Corynebacterium spp.

Predisposing factors

General

• Poor uterine tone:
  • Hypocalcemia Primary maternal dystocia.
  • Dystocia Dystocia.
  • Large litters.

Specific

• Non-sterile manipulation of dystocia.
• Retained placentae Retention of fetal membranes and fetus /puppies.
• Fetal death.

Pathophysiology

• Uterine infection caused by:
  • E. coli Escherichia coli.
  • Proteus spp Proteus spp.
  • Staphylococcus spp Staphylococcus spp.
  • Streptococcus spp Streptococcus spp.
  • Other gram-negative and gram-positive vaginal commensals.

• Bacteria normally found in → uterus → proliferate in lochia → endotoxin release → :
  • Interference with ADH (see pyometra complex Pyometra ) → dehydration, uremia.
  • Pathogen chemotaxis → neutrophilia → pooling of neutrophils in uterus → left shift leukogram.

Timecourse

• Usually within 1 week of whelping (or other predisposing event).

Diagnosis

Treatment

Prevention

Outcomes