Cat Chemotherapy

Cat chemotherapy is very similar to human chemotherapy. Your cat is injected with a combination of drugs designed to kill rapidly-reproducing cancer cells. Cats actually tolerate chemotherapy better than humans, though there are still some side effects.

Chemotherapy Drugs

When treating cancer in humans, the goal is to cure the cancer, which often means aggressive chemotherapy and radiation. It usually takes cats much longer to be diagnosed with cancer since they can't tell us when something feels weird, so cancer is usually much further along. Often the goal of cancer treatment is to prolong the life of your cat, not necessarily cure the cancer.

This means that chemotherapy treatment is generally much milder for pets. Instead of using a 10-drug combination, your veterinarian may recommend a three-drug combination and will often choose drugs that work on different areas of the body and have different side effects so that your cat's body isn't overwhelmed with drugs.

These drugs are designed to kill cancer cells, but the drugs often don't distinguish well and kill many of the cells your cat's body needs. Drug combinations are designed to minimize this effect, but it can't be completely eliminated.

Drugs are generally administered intravenously through a catheter since the drugs can be highly irritable if they leak and come in contact with your cat's skin. Your cat will often have to spend a few hours at the vet receiving the drugs and then being observed.

Since chemotherapy drugs are excreted through the liver and kidney, your cat's liver and kidney enzymes may need to be tested regularly to ensure that his body can handle treatment. He may also need blood work for a white blood cell count to make sure his body can still fight illnesses if necessary.

Side Effects of Chemotherapy

The common symptoms of human chemotherapy often don't appear in cats. Your cat probably won't lose much hair, though he may lose his whiskers during treatment. He may experience an upset stomach, as humans do after chemotherapy, and may vomit or have diarrhea. He probably won't want to eat soon after treatment. This is OK as cats can go a day without eating if they don't feel well.

If your cat seems extremely weak, has an elevated temperature, experiences a color change in the gums, such as pale yellow, blood in urine or tremors and convulsions, consult your veterinarian immediately.

There is no risk to you from his chemotherapy drugs, so don't be afraid to pet and cuddle with your cat. He will need your comfort! However, his urine and feces may be more harmful to your health, so consult with your veterinarian on proper disposal.

If your cat is an outdoor cat, consider keeping him indoors where he has less risk of contracting a bacteria or virus while his body is trying to fight cancer. Also, keep him isolated from any sick cats with whom he may come in contact.

The decision to give your cat chemotherapy is difficult since it is expensive and may provide discomfort to your cat. However, it is much milder than human chemotherapy and may add years to your cat's life.