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Dogs + Cancer & Tumors

  • Tumors of the prostate are relatively uncommon in dogs and extremely rare in cats. Clinical signs include bloody urine, or straining to urinate or defecate. Metastasis to the pelvic bone and/or lumbar spine is likely. Diagnosis and treatment options are discussed. Prognosis is considered poor.

  • Prostatic disease can be uncomfortable for a dog, particularly if it causes compression of the urethra or colon. Because there are many diseases of the prostate, it is necessary to perform several tests to determine the exact cause of a patient's condition. This handout provides explanations of the seven most common conditions affecting the prostate and the corresponding approaches to treatment.

  • Radiation is a type of energy produced naturally by the sun, earth, and rocks and artificially by machines. Although several types of tumors can be treated with radiation therapy alone (e.g., nasal tumors, brain tumors, and certain types of lymphoma), radiation therapy is most commonly used to destroy or limit the growth of cancer cells left behind (i.e., microscopic disease) after a tumor has been surgically removed. Side effects depend on the type and location of the tumor and its surrounding tissues.

  • Round cell tumors are among the most common skin tumors in dogs, and they typically form just under the skin, although they may change the surface of the skin above them. It is impossible to diagnose any of them without a veterinary pathologist analyzing a tissue sample of the tumor under a microscope. If detected early, most round cell tumors can be easily removed.

  • Salivary gland tumors are rare in dogs and cats. The mandibular and parotid glands are most commonly affected. Signs include swelling of the upper neck or ear base, halitosis, anorexia, weight loss, difficulty eating, pain, and lethargy. The treatment of choice is usually surgical excision. If complete excision is not possible, adjunct radiation therapy may be pursued.

  • Seizures and syncope are commonly confused with one another due to similarities in the appearance of these episodes. Both present with collapse but there are several details, explained in this handout, that can differentiate between them, which is important for determining treatment. The prognosis for each condition varies depending on the underlying causes.

  • Soft tissue sarcomas are a broad category of tumor types. These tumors can arise anywhere there is soft tissue, including the limbs, joints, face, intestine and reproductive tissues. Routine staging is recommended to help dictate therapy. If surgery is possible, wide-surgical excision is pursued. If removal is incomplete or not possible, adjunct radiation therapy can be pursued. Metronomic chemotherapy may provide benefit in patients when few options exist.

  • Squamous cell carcinoma is a tumor of the cells that make up the contact or upper layer of the skin. UV light exposure has been described as a developmental factor in people, though it is still in question as to the role for dogs. Several breeds are known to be predisposed to this type of cancer. About 30% of dogs with the digital form of the disease will have evidence of spread. Regardless of the location, surgery is typically the treatment of choice, and staging is usually recommended prior to any surgery.

  • Stomach tumors are uncommon in dogs and cats. There are many kinds, including leiomyosarcomas, lymphomas, adenocarcinomas, mast cell tumors, fibrosarcomas, plasmacytomas, gastrointestinal stromal tumors (GISTs), and carcinoids (all malignant); and leiomyomas, adenomatous polyps, and adenomas (benign). Most tumors are malignant. Stomach tumors are more prevalent in older animals, males, and certain breeds. The signs of stomach tumors include chronic vomiting, inappetence, lethargy, and weight loss. Sometimes tumor ulceration will cause anemia. Paraneoplastic syndromes are possible with the muscle tumors. Stomach tumors may be diagnosed with imaging, endoscopy, or surgery, with a biopsy. Treatment may involve surgery, chemotherapy, or radiation therapy.

  • Skin gland, hair follicle, and sebaceous gland tumors are more commonly found to be benign. Matrical carcionoma and sebaceous gland adenocarcinoma are rare and more aggressive forms of the disease. Regardless of the type (sweat, hair, or sebaceous) diagnosis is made by fine needle aspiration, biopsy, and/or initial surgical removal and histopathology. In the majority of cases, surgery is recommended and other treatments are unnecessary. Chemotherapy and/or radiation therapy in pets with matrical carcinomas or sebaceous gland adenocarcinomas may be recommended.