Many animals with uterine tumors have no clinical signs of illness. This is because most tumors are benign and therefore do not spread to other organs. The most common tumor types are leiomyomas (fibroids) and fibromas. Malignant tumors are often adenocarcinomas or leiomyosarcomas. Large tumors may cause compression of other abdominal organs and may result in constipation, vomiting, or frequent urination. Abdominal distension is sometimes noted due to large tumor size or development of fluid in the abdomen secondary to the tumor.

In many cases, the tumor may be present concurrently with an infection in the uterus, called pyometra. Cats with pyometra are commonly lethargic, excessively thirsty, anorexic, vomiting and often have vaginal discharge. Licking of the vulva is common in animals with vaginal discharge, which may prevent observation of the discharge itself. Other conditions may cause similar clinical signs to those seen in animals with uterine tumors. These include:

Vaginitis or vaginal tumors. Infection or tumors of the lower reproductive tract may cause discharge and licking as well.

Tumors of other abdominal organs. Masses associated with the liver, spleen, or gastrointestinal tract may also cause abdominal distension and possible fluid accumulation in the abdomen.

Liver/kidney/gastrointestinal/metabolic diseases. Many diseases can cause general lethargy, anorexia and vomiting. These are not signs specific to one organ system, but should prompt a visit to the veterinarian for appropriate evaluation.