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Tumors

  • 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 therapy is the medical use of high dose radiation to destroy cancer cells by damaging the cells’ DNA to interfere with cell replication and kill them. It may be used on its own or in combination with other treatments, such as surgery or chemotherapy, or to reduce the size of very large tumors prior to surgery. There are several radiation protocols used in veterinary medicine. Your veterinary oncologist will choose the therapy most appropriate for your pet’s individual situation.

  • 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. Older dogs and cats, Poodle and Spaniel breed dogs and Siamese breed cats, and male cats are at a higher risk for salivary gland tumors. The most commonly reported salivary gland tumor is the adenocarcinoma. Signs include swelling of the upper neck or ear base, halitosis, anorexia, weight loss, difficulty eating, pain, and lethargy. Fine needle aspiration may be used to differentiate between neoplastic and non-neoplastic masses. Biopsy provides a definitive diagnosis. General staging as well as CT scan or MRI are recommended since these tumors have a tendency to be locally invasive and metastasize. The treatment of choice is usually surgical excision. If complete excision is not possible, adjunct radiation therapy may be pursued.

  • A seizure is a sudden surge in the electrical activity of the brain causing signs such as twitching, shaking, tremors, convulsions, and/or spasms. Epilepsy is used to describe repeated episodes of seizures. With epilepsy, the seizures can be single or may occur in clusters, and they can be infrequent and unpredictable or occur at regular intervals. Since many different diseases can lead to seizures, it is important to perform diagnostic tests to investigate the underlying cause of the seizures. Treatment of seizures in the cat depends on the nature of the underlying disease.

  • 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 tumors that can develop over the chest, back, side, legs, and facial tissues of your pet. The clinical signs depend on where the tumor is located and the tissues that are affected. Often, pets have a noticeable mass that is growing in size. One of the biggest concerns with soft tissue sarcomas is their ability to invade the local surrounding tissues. The most commonly pursued treatment is surgery. Chemotherapy is not usually pursued as a primary treatment unless surgery or radiation are not options for your pet based on the tumor size or location.

  • Squamous cell carcinoma (SCC) 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 and appears to be associated with its development in cats. Areas affected include the ear tips, skin, toes, or peri-ocular region. Fine needle aspiration or biopsy may be performed for diagnosis. The metastatic rate does not appear overly clear, though staging is always recommended. SCC of the toe can occur as a primary tumor or may have spread from the lung (lung-digit syndrome). Surgery is almost always recommended in any case of SCC; the role of chemotherapy is controversial. Radiation therapy has an excellent response rate in cats with the SCC affecting the nasal planum and may give long-term tumor control.

  • 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.