Ovarian Tumors in Dogs
Key takeaways
Ovarian tumors in dogs are rare masses developing due to unregulated cell growth in an intact female dog’s reproductive organs.
- There are different types of tumor that may develop from the ovarian tissue and most ovarian tumors are malignant
- Symptoms include hair loss, vulvar swelling, abdominal pain, being ‘in heat’ more often, and vulvar discharge
- Ovarian cancers are often asymptomatic, and tumors have often metastasized by the time diagnosis is made
- Diagnosis includes diagnostic imaging, bloodwork, cytology, and biopsies
- Spaying is the most effective treatment method, and may be combined with chemotherapy for malignant tumors
- The prognosis for ovarian tumors is typically guarded as most have metastasized by the time of diagnosis
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A closer look: Ovarian Tumors in Dogs
Ovarian tumors are rare, and occur only in intact female dogs. Tumors are often locally aggressive.
Ovarian cancer is often asymptomatic, and may spread to a dog’s lungs, lymph nodes, liver, kidney, and pancreas before diagnosis.
Dogs presenting with symptoms require immediate medical attention, as early diagnosis and treatment affords the best prognosis.
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Risk factors
Ovarian tumors are often asymptomatic. These tumors may only be identified when diagnostic imaging is conducted for other reasons.
Some ovarian tumors increase hormone production, affecting behavior. A dog affected in this way may go in heat more often, and experience aggression.
Possible causes
There are many different types of ovarian tumors, each developing as a result of unregulated cell growth. Some of the most common ovarian tumors in dogs are:
Carcinomas develop out of the ovaries’ outer tissue. Carcinomas commonly metastasize to nearby lymph nodes.
Dysgerminomas grow from reproductive egg cells (germ cells). They may be metastatic, and spread to the liver, kidney, pancreas, or adrenal glands.
Teratomas also grow from germ cells. Some forms of teratomas are malignant, and may metastasize to other locations in the body. .
Granulosa cell tumors are derived from hormone producing cells. The tumor cells can produce large amounts of hormones, including estrogen. The excess hormones can cause hormonal imbalances leading to hair loss or irregular heat cycles. These may spread into the pancreas, liver, and lungs.
Main symptoms
Testing and diagnosis
Sometimes ovarian tumors are identified during a spaying surgery.
Otherwise, diagnostics include:
- Physical examination
- Bloodwork, including measuring progesterone levels
- Diagnostic imaging, such as abdominal x-rays or ultrasound
- Cytology of abdominal or thoracic fluid
- Biopsy of the ovarian mass
Steps to Recovery
Generally, ovarian tumors are treated by a spaying operation. In cases where the tumor is malignant, chemotherapy may be used as well.
Prognosis is guarded, as ovarian tumors are typically malignant, and often metastasize by the time they are diagnosed.
Follow-up appointments may be indicated, to ensure no additional tumors are developing.
Prevention
Spaying prevents ovarian tumors.
Tumors are not contagious.
Is Ovarian Tumors in Dogs common?
Ovarian tumors are rare, but more common in older animals.
Teratomas are more common among younger patients.
Typical Treatment
- Surgery (Spaying)
- Chemotherapy
