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Synonyms: Chronic Closed Infection of Uterus

Pyometra is a chronic uterine infection, typically caused by a cervix that does not open normally. It overlaps with the diagnosis of endometritis.

In a pyometra, infection takes hold and continues because the uterus cannot empty or clear the infectious agents. The uterus fills with pus and becomes akin to a huge abscess. In cases of a severe pyometra, the uterus may contain 5 gallons of pus or more.

This closed infection makes the mare feel terrible, causing lack of appetite, fever, and colic signs due to stretch on the uterine wall. Treatment involves a combination of opening of the cervix, drainage of pus, uterine flushing with antibiotic treatment. Ultimately, surgical removal of the uterus (hysterectomy), may be required. In most cases, mares that have a pyometra become permanently infertile.


  • What are the chances that I can breed or rebreed this mare?
  • What underlying condition contributed to the development of this problem?

    Early treatment of uterine infections. Recognition and treatment of cervix disorders that predispose this development.

    Helpful Terms & Topics in HSVGWritten, Reviewed or Shared by Experts in Equine Health

    Author: Doug Thal DVM Dipl. ABVP


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