Metritis is postpartem infection of the uterus. Predisposing causes include prolonged delivery, dystocia, and retained fetuses or placentas. Escherichia coli is the most common bacterium isolated from the infected uterus; streptococci, staphylococci, Proteus sp, and others are isolated less frequently.
The primary clinical sign is purulent vulvar discharge. Bitches or queens with metritis are usually depressed, with signs of fever, lethargy, and inappetence, and may neglect their offspring. Pups may become restless and cry incessantly. Metritis should be considered in any postpartum animal with signs of systemic illness or an abnormal vaginal discharge. A large, flaccid uterus may be palpable. Radiographs should be taken to determine whether fetuses or placentas are retained. The hemogram may show leukocytosis with a left shift.
Treatment includes stabilization with IV fluids, supportive care, and antibiotic therapy based on culture and sensitivity testing of the vulvar discharge. Prostaglandin F2α (0.1–0.25 mg/kg, SC, for 2–3 days) or oxytocin (5–20 U in bitches, 2–5 U in queens, IM) may help evacuate the uterine contents. Ovariohysterectomy is recommended after initial stabilization if the animal is extremely ill or if future reproduction is unimportant. Otherwise, it should be considered an elective procedure to be performed when lactation has ceased.