Estrogen Excess (Hyperestrogenism)

Condition Overview

Hyperestrogenism is caused by the overproduction of estrogen from the ovaries or testicles (in males).

Symptoms

Signs of hyperestrogenism are feminization with enlargement of the mammary glands and nipples in both sexes, enlargement of the vulva and clitoris in females, and the development of a pendulous (hanging) prepuce (the retractable skin that covers the genitals) in males. Females may have irregular heat cycles, false pregnancy, and pyometra (pus infection).

Skin and coat changes begin in the perineum around the genital areas and proceed to the underside of the abdomen. Typically, the hair becomes dry and brittle, falls out easily, and fails to regrow. Later the skin becomes darkly pigmented. A dry, flaky seborrhea (dandruff) often develops, particularly in females. The coat and skin changes follow a symmetrical pattern.

All symptoms +

Causes

In females, it is associated with granulosa cell tumors and cysts of the ovaries. In males, it is caused by testicular tumors.

Diagnosis

The cause of the hyperestrogenism should be determined by physical examination, ultrasound, endocrine blood tests, and if necessary, laparoscopy or exploratory surgery.

Treatment

Hyperestrogenism in both sexes responds well to neutering.

Prevention

Have your pet spay or neutered.

Support

Please contact your veterinarian if you think your pet may have this condition.