Educational Articles

Cats + Tumors

  • These notes are provided to help you understand the diagnosis or possible diagnosis of cancer in your pet. For general information on cancer in pets ask for our handout "What is Cancer". Your veterinarian may suggest certain tests to help confirm or eliminate the diagnosis, and to help assess treatment options and likely outcomes.

  • Endocrine glands produce specialized chemicals called "hormones". These regulate and integrate many activities to maintain internal stability of the body.

  • Endocrine glands produce specialized chemicals called “hormones”. These regulate and integrate many activities to maintain internal stability of the body. The hormones pass directly into the blood to affect target cells elsewhere.

  • Dogs and cats have a pair of anal sacs, one located on each side of the anus between the external and internal anal sphincter muscles. The sacs are lined with modified sweat glands called anal glands.

  • Basal cell tumors are a common type of skin tumor arising from cells in the deeper layers of the skin. They vary in size, from a few centimeters to inches in diameter, and most commonly appear as single, firm, hairless, raised masses in the skin, often on the head, neck, or shoulders. Most of these tumors are benign but removal may still be considered to prevent trauma or secondary infection. Surgical removal is curative in most cases.

  • Fibrous tumors, including hamartomas, are a group of benign tumors arising from fibrous and fibrous-like tissues. Nodular dermatofibrosis can be secondary to (or a consequence of) tumors in the kidney or uterus. Fibrous tumors can develop as the result of underlying, repeated trauma (e.g., pressure on the elbows when lying on hard surfaces and self-trauma with skin allergies). Therefore, once a diagnosis has been made, determining and understanding the underlying cause is important.

  • Non-cancerous bone tumors are rare in cats and are mainly due to abnormal development. They include bone cysts and single or multiple lumps of bone in abnormal places (exostoses).

  • A chemodectoma is a type of tumor made up of chemoreceptor cells. Chemoreceptor cells detect chemical changes in the body and respond by regulating chemical or physical processes. These tumors are most often seen along one of the carotid arteries and the aorta. Brachycephalic breeds are more predisposed to these types of tumors, though they may occur in any dog breed. These tumors are usually locally aggressive, however, there are rare cases of metastasis to other organs, including the lungs, lymph nodes, and bone.

  • Chemotherapy is the therapeutic use of chemical agents to destroy, or inhibit the growth and division of cancer cells. Chemotherapy is usually used when tumors are widespread or when there is significant or immediate risk of spread from the primary location. It is often used following the surgical removal of tumors. In some cases, chemotherapy is started prior to surgery. Different protocols are used depending on the drug and the type of cancer being treated. The side effects of chemotherapy are related to the effects of chemotherapy on normal – as well as cancerous – cells. The principal goal with cancer care in pets is to provide cancer control without reducing quality of life. With pets, chemotherapy protocols are purposefully designed so the treatment does not become worse than the disease.

  • Chondrosarcomas arise from cartilage, which is a connective tissue primarily found where bones meet with joints, as well as at other locations in the body (such as the nasal cavity, ribs, etc.). Chondrosarcoma is a rare tumor in cats, but it can occur. The reason why a particular pet may develop this, or any tumor or cancer, is not straightforward. Clinical signs of chondrosarcoma may vary significantly, depending upon where the tumor arises. Although the mass may grow rapidly, less than 20% of feline chondrosarcoma cases metastasize to other parts of the body. Therefore, surgical removal is curative in many cases.