is a chronic venereal disease of horses that is transmitted during coitus and caused by T equiperdum. The disease is recognized on the Mediterranean coast of Africa and in the Middle East, southern Africa, and South America; distribution is probably wider.
- Signs may develop over weeks or months. Early signs include mucopurulent discharge from the urethra in stallions and from the vagina in mares, followed by gross edema of the genitalia. Later, characteristic plaques 2–10 cm in diameter appear on the skin, and the horse becomes progressively emaciated. Mortality in untreated cases is 50%–70%.