Chemotherapy is routinely recommended by oncologists to treat underlying cancer that has been diagnosed in your pet. Hearing the diagnosis of cancer in your pet can be stressful, and the prospect of undertaking chemotherapy treatments can be equally difficult because of the human experience with cancer therapy. However, the primary goal in veterinary oncology is to maintain a good quality of life for the patients and for them not to experience significant adverse effects from their treatments. Knowing how anti-cancer chemotherapy drugs work allows us to formulate a treatment protocol for your pet while focusing on the mutual goal of a good quality of life.
Chemotherapy may be used as the sole treatment for certain cancers or it may be used in combination with other treatment modalities, such as surgery, immunotherapy, and radiation therapy. Chemotherapy will likely be recommended for cancer that has already spread to other areas of the body, for tumors that occur at more than one place in the body, or for tumors that are too large to be removed surgically. In some cases, chemotherapy can be used to try to shrink large tumors prior to surgery or to help eliminate certain types of microscopic cancer cells that have not been completely removed surgically. For cancers that are at a high-risk for metastasis early in the course of a disease, chemotherapy can be used after surgery or radiation therapy to help slow down the growth of cancer cells in other parts of the body.
Chemotherapy can be administered by many methods, although the two most common routes for our veterinary patients are intravenously (in a vein) or orally (by mouth). Our goal in treating your pet is to minimize any adverse effects related to chemotherapy with supportive medications (anti-nausea, anti-diarrheal, antibiotics) that can be administered by mouth at home. Although negative impacts on quality of life are uncommon, the most common side effects that may occur during therapy would be mild gastrointestinal upset, short episodes of tiredness, or decreases in the blood cell counts. The majority of side effects experienced by your pet can be treated with oral medications at home. Chemotherapy is administered on an outpatient basis and very rarely do pets need to be hospitalized for individual treatments or side effects.
The most common canine and feline tumors treated with chemotherapy or targeted therapies are lymphomas, osteosarcoma, hemangiosarcoma, bladder tumors, mast cell tumors, mammary gland tumors, anal sac tumors, melanoma, thyroid tumors, and various gastrointestinal tumors. The treatment intervals of chemotherapy administration, financial commitments, and overall prognosis will vary depending on the underlying type and stage of cancer. Your oncologist will formulate a specific treatment protocol for your pet and will work with you to ensure that your pet has a good quality of life.