What Is It?
Uterine adenocarcinoma is the most common cancer affecting female rabbits. It is a slowly developing cancer of the uterus. In general, intact or unspayed rabbits older than 4 years of age have a 50-80% chance of developing this tumor. Some breeds and color types (tan, French silver, Havana, Dutch) seem more susceptible. Local invasion to the surrounding abdominal organs as well as blood-borne spread to the liver, lungs, lymph nodes, brain, and occasionally bone can occur, though metastasis or spread of the tumor usually occurs late in the disease.
In breeding does, clinical signs include decreased fertility, small litter size, and an increased incidence of stillbirths. In pet rabbits, the most commonly recognized sign is bloody urine or a bloody vaginal discharge. In late-stage cancer patients, a lack of appetite, lethargy, depression, and occasionally difficulty breathing may be observed. Many rabbits with uterine adenocarcinoma also have mammary gland (breast) cancer as well.
Diagnosis of uterine adenocarcinoma begins with a complete medical history and a thorough physical examination. Often, abdominal palpation reveals an enlarged uterus or discrete uterine masses. Routine lab work including a complete blood count, a serum chemistry profile, and a urinalysis is helpful to identify any concurrent diseases. Radiographs (x-rays) and abdominal ultrasound are necessary to evaluate the uterus as well as to screen for any metastasis or spread of the original tumor.
Ovariohysterectomy or spaying is the treatment of choice for this disease. If the cancer is localized to the uterus, this treatment is curative. Abnormal uterine tissue should be submitted for histopathology to obtain a definitive diagnosis and help predict a prognosis. Because metastasis or spread of the tumor can not always be identified, a guarded prognosis is often given. However, in reality, these rabbits often do quite well if detected early enough. Chemotherapy has been attempted in a few cases, but is not very successful.
Prevention is the key! We recommend spaying all female rabbits, preferably between the ages of 6 and 12 months. Rabbits spayed later in life should have a thorough preanesthetic examination, including screening blood work and preferably chest radiographs. In addition, it’s important that your pet rabbit has annual or semi-annual physical examinations performed by your veterinarian in order to detect diseases early.
Content prepared by St. Francis Animal and Bird Hospital, 1227 Larpenteur Ave. West, Roseville MN. 55113