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Tumors

    • The definition of a pneumothorax is an accumulation of air outside the lungs, but inside the chest wall. The air outside the lung prevents the lungs from inflating normally, and can lead to lung collapse. There are several variations of pneumothorax.

    • Primary liver tumors in dogs and cats are rare. There are 4 types: hepatocellular tumors, bile duct tumors, neuroendocrine tumors, and sarcomas. These cancers can be massive, nodular, or diffuse in form. In dogs, most liver tumors are malignant, while in cats, most are benign. The signs of liver tumors range from being asymptomatic to having inappetence, fever, lethargy, and weight loss; and less commonly, nausea, vomiting and diarrhea; increased drinking and urination; and jaundice. Occasionally there are neurological signs, such as seizures. With tumor rupture and intrabdominal bleeding there may be weakness, collapse, and difficulty breathing. The diagnosis is based on history, clinical signs, exam findings, diagnostic imaging, and FNA or liver biopsy. A biopsy is best for a definitive diagnosis. Surgery is the treatment of choice for most primary liver tumors followed by chemotherapy. Chemoembolization is a newer treatment.

    • 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.

    • Malignant lymphoma (lymphosarcoma) and leukemia are among the most common malignancies seen in ferrets. Diagnosis may be made by fine needle aspiration or biopsy. For a dedicated owner with a compliant patient, surgery and/or treatment with chemotherapy is an option. Remission of lymphoma is possible with treatment in ferrets, but recurrence is common. Ferrets also commonly develop insulin-producing tumors of the pancreas that lower the ferret’s blood sugar and cause weakness, weight loss, lethargy, seizures, coma, and death. Insulinoma commonly spreads from the pancreas to the liver, so surgical removal of pancreatic insulinoma nodules may not be curative. Affected ferrets respond well for months to years to medical therapy with glucose-promoting drugs (prednisone) and anti-insulin drugs (diazoxide). Drugs suppress effects of the tumor but do not eliminate it; and ferrets on medical treatment must have their medications increased over time as the tumor grows.

    • Tumors of the prostate are relatively uncommon in dogs and extremely rare in cats. The most common tumor is prostatic adenocarcinoma. Clinical signs include blood in the urine, changes in urination habits, or straining to urinate or defecate. Metastasis to the pelvic bone and/or lumbar spine is likely. FNA of the prostate aids in the diagnosis, though surgical biopsy may need to be considered. Treatment is limited. Stents may be placed in patients with tumors obstructing the urethra. Radiation therapy in conjunction with NSAID therapy has shown significant survival advantage when compared to pets who did not receive NSAID therapy. The role and/or benefit of chemotherapy is not well understood.

    • 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.

    • An insulinoma is a tumor that involves the beta cells of the pancreas. Beta cells are the cells that produce the hormone insulin. Insulinomas are surprisingly common in ferrets.