Educational Articles

Dogs + Tumors

  • Transmissible venereal tumors (TVTs) arise from immune cells called histiocytes. Dogs develop this tumor from direct contact with already affected dogs, most notably during sexual contact. The tumors typically develop on the penis, prepuce, vulva, and vagina, though can develop on the skin, eyes, oral, and nasal cavities as well. The tumors are usually cauliflower-like in appearance. Clinical signs are dependent on the location, but typically the tumors ulcerate and bleed. Metastasis is rare but can affect lymph nodes and other areas of the body. Treatment may include chemotherapy or radiation therapy (for those resistant to chemotherapy). Prognosis is usually good with a high response rate to chemotherapy.

  • Urinary tract tumors can occur anywhere along the urinary system, from the kidneys to the urethra. They are more likely to be malignant than benign. In dogs, the most common type of urinary tract tumors are bladder tumors, and of these, the most common is transitional cell carcinoma (TCC). Lymphoma and renal carcinoma are the two most common primary kidney tumors in cats and dogs, respectively, but these are relatively rare. Staging is recommended with all urinary tract tumors. With TCC, staging should include X-rays of the spine and/or hips since bone metastasis is possible. With bladder tumors, treatment is usually medical (e.g., NSAIDs) with/without chemotherapy and radiation therapy. With unilateral kidney tumors, nephrectomy is usually the treatment of choice, while with bilateral kidney tumors, chemotherapy may be considered. Treatment and prognosis always depend on the type of tumor and degree of local invasion and metastasis.

  • Uterine tumors are quite rare in North American pets, mainly due to routine spaying practices. Several types of tumors can arise from the tissues of the uterus. How the tumor will affect your pet is entirely dependent on the location and type of tumor. By far, uterine cancer is most commonly diagnosed by abdominal ultrasound or during a spay procedure. Full staging is recommended prior to surgery to determine if the cancer has metastasized. Treatment for solitary masses without evidence of spread typically involves ovariohysterectomy. If metastasis is present, chemotherapy should be considered, however its efficacy is not completely known. Without evidence of spread, uterine tumors carry a good prognosis.

  • Vascular tumors of the skin develop from the blood vessels of the skin. These tumors may arise anywhere on the body and appear as a firm and raised lump on or under the skin. Hemangiomas may ulcerate and bleed; hemangiosarcomas may bleed into the surrounding tissues. This type of tumor is typically diagnosed via a tissue biopsy or surgical removal of the entire tumor. Surgery is the recommended treatment for vascular tumors of the skin.

  • Visceral vascular tumors are tumors that develop from the blood vessels found in the internal organs of the body, most commonly the heart, liver, and spleen, although other locations, such as the urinary bladder, are possible. There are two forms of visceral vascular tumors: hemangiomas and hemangiosarcomas. Certain breeds, such as German Shepherds, Labrador Retrievers, and Golden Retrievers, are particularly predisposed to developing hemangiosarcoma. The clinical signs vary depending on the location of the tumor. This type of tumor is often diagnosed with ultrasound of the chest or abdomen depending on the location of the tumor. Surgery is the recommended treatment option and chemotherapy may be recommended.

  • Cancer is the result of genetic damage to cells. While some breeds may be more predisposed to certain forms of cancer, age-related changes and environmental factors are also often at fault. Some tests can be performed to determine the type of cancer present. Treatment options are available but do not necessarily cure cancer.

  • Regular preventive health care for your dog can increase the length and quality of her life. Health care guidelines are established and kept up to date using the most recent evidence-based recommendations including the recommendation that all dogs receive a complete veterinary examination at least once a year or more frequently, depending on their individual needs and health concerns.