Chemotherapy drugs are used to inhibit the growth of or kill cancer cells. It can be the primary treatment to kill or slow the growth for some types of cancer. In other cases, chemotherapy is used in conjunction with radiation or surgery. When chemotherapy is used in conjunction with the other options, surgery or radiation treat the visible cancer and chemotherapy is used to destroy any cancer cells that escaped the area and are still too small to detect.
Chemotherapy is a systemic therapy utilizing drugs to damage cells that grow and divide quickly, which is why it is so effective on cancer cells. Unfortunately, most chemotherapy drugs do not specifically target only cancer cells, but may also affect normal cells that are in the process of dividing and growing. The body does have normal cells that divide rapidly which accounts for the side effects that can be seen with chemotherapy. Because the body needs time to recover from the loss of these cells, we give chemotherapy drugs in intervals.
Different types of cancer respond to different drugs. Sometimes we just use one drug and other times we will use a combination. Doses are given at intervals from daily to monthly, depending on the type of cancer and drug along with how far along a pet is in the treatment process. Chemotherapy drugs are administered intravenously, in the muscle or given orally at home and the duration of treatment depends on the type of cancer. Treatment protocols range from 19 to 52 weeks with some requiring maintenance treatment, which can last an indefinite period of time.
Why chemotherapy is different for pets than people
The prospect of chemotherapy for a pet is frightening for many people because they’ve had personal experiences with chemotherapy or know someone who has. People are treated with very high doses because the goal is to get rid of the cancer for good. People can understand why they are getting so sick and they know that they will eventually get better. They are able to make the conscious choice to go through months of illness in exchange for years of health.
Animals do not understand that something good can come out of being so sick. In fact, when they are sick for too long, some will lose their will to live. That’s why we use significantly lower doses of chemotherapy in pets to minimize those side effects.
Unfortunately, we are not expecting to fully kill all of the cancer with chemotherapy. Our goal at Veterinary Specialty Center is not only to keep the cancer inactive (in remission) but also to allow your pet to live a good happy life for however long that may be.
The majority of patients experience mild side effects that are easily controlled with medications. Some patients experience no side effects while others are more sensitive to certain drugs. If they do experience more severe side effects some patients will require hospital care. If this should happen we will adjust their treatment to minimize the side effects.