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Professional Version

Pyometra in Production Animals


Fabio Lima

, DVM, MS, PhD, DACT, University of California, Davis

Reviewed/Revised Aug 2022 | Modified Oct 2022
Topic Resources

Clinical Signs of Pyometra in Production Animals

Pyometra is characterized by the accumulation of purulent or mucopurulent exudate in the uterus. In cows, it is invariably accompanied by the persistence of an active corpus luteum and interruption of the estrous cycle. In affected mares, the cervix is often fibrotic, inelastic, affected with transluminal adhesions, or otherwise impaired. Mares may continue to cycle regularly, or the cycle may be interrupted. Discharge from the genital tract may be absent or intermittent and corresponding to periods of estrus. In general, affected animals do not exhibit any systemic signs of illness, but affected mares may be in poor condition. In both cows and mares, pyometra must be distinguished carefully from pregnancy before beginning treatment.

Treatment of Pyometra in Production Animals

In cows, the treatment of choice for pyometra is the administration of PGF2-alpha or its analogs at normal luteolytic doses. Expulsion of exudate and bacterial clearance of the uterus follows in ~80% of treated cases. Although the first-service conception rate after treatment may be low, most cows may be expected to conceive within three or four inseminations. The treatment may need to be repeated in ~20% of cows. No intrauterine treatment is recommended in conjunction with the prostaglandin.

In mares, lavage of the uterus using large volumes of fluid is recommended; however, the condition frequently recurs, and permanent cure in these cases requires hysterectomy or wedge resection of the cervix to allow continual uterine drainage, a salvage procedure that allows the continued use of the mare but renders it infertile.

Pyometra is seen in small ruminants, swine, and other species; diagnosis is rendered more difficult by animal size and management practices. If pyometra is diagnosed, evacuation of the uterus is recommended.

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