Cat Chemotherapy Drug Side Effects
Veterinarian Reviewed on April 2, 2014 by Dr. Janice Huntingford
Cat Chemotherapy Drug Side Effects
Chemotherapy treatments for Cat Cancer, does not have the same degree of side effects in cats as it does in humans. Cats are given lower doses than humans. Side effects will also vary with the drug used. The decision to use chemotherapy to treat cancer in cats can prove to be a very expensive one. The fees will depend on the size of the cat. The larger the cat, the more medication needed and consequently the higher the fees. Chemotherapy can run into thousands of dollars, but you will pay with each visit and not in one lump sum. If you have cat insurance, you will probably be reimbursed for some of the money you pay.
Typical side effects
Side effects will vary with the drug used, but some are fairly common with all of them in both cats. Diarrhea is one side effect that is very common and therefore your vet may give you a round of flagyl to help with the diarrhea. Several days after the treatment, you will be happy to have it on hand. Your cat will have a decrease in appetite with some and an increase with others. The same will apply with thirst. It is always wise to pay attention to your cat’s water consumption. They should be encouraged to drink more and flush the medications out of their bodies.
Prednisone
Prednisone is not specifically a chemotherapy drug. It will however buy some time and may be used as part of the protocol. It is also used to counteract some of the negative side effects. With prednisone you can expect the following.
• Some mild changes in their behavior
• Less tolerant to exercise
Elspar
• Low white cell count
• Inflammation and possible damage to the injection site
• There can be tremors which may indicate the low white count
Cytoxan
• Low white cells
• Bladder toxicity which and lead to blood in the urine and cystitis.
• Lasix or another diuretic may be given along with it to insure that the drug is expelled from their bladder and decrease the possibility of cystitis and infection.
Adriamycin
If your cat receives an excessive amount of this drug during their chemo treatment, it can cause heart problems. It has a cumulative effect on the heart. Some veterinarians will do a chest film or ultrasound prior to the treatment to assure that the heart has not been damaged. There are some vets who recommend CoQ10 as a supplement during the administration of this drug.
Conclusion
There are other drugs that can be used as well. A lot will depend on the success of the one that is being used. If it is not affecting the tumors, your veterinary oncologist may opt to change it to another.
Cats do not have significant hair loss during chemo. Human hair grows continuously but most cats do not.
Sign up for our newsletter and receive more articles and the latest pet health updates and special offers.
Our Expert

Janice Huntingford, DVM, has been in veterinary practice for over 30 years and has founded two veterinary clinics since receiving her Doctor of Veterinary Medicine at the Ontario Veterinary College, University of Guelph. She has studied extensively in both conventional and holistic modalities. Ask Dr. Jan