Chemotherapy in Dogs and Cats - for Pet Owners

Chemotherapy is medication used to treat cancer. It is given either as oral medication or by injection.

Dogs and cats tend to tolerate chemotherapy treatment well with most not experiencing side effects. This is because lower doses of chemotherapy are given compared to humans in order to maximise quality of life.

Approximately 20% of dogs and cats will experience nausea, vomiting or diarrhoea following chemotherapy. This tends to occur in the 5 days following treatment and resolves within a few days. Your vet can provide medications to treat symptoms and aid recovery. We may also recommend that further doses of chemotherapy are reduced in order to maintain excellent quality of life.

Hair loss can occur in breeds with continuously growing hair (e.g. Poodles). Some dogs and cats will also lose their whiskers but this is less common.

Occasionally patients receiving chemotherapy will develop serious infections during their treatment due to reduced immunity. A veterinarian should assess any chemotherapy patient that is unwell as soon as possible as antibiotic treatment may be required.

Some drugs have specific side effects/risks that can be discussed on a case-to-case basis.

Health and Safety Aspects of Chemotherapy in Pets:

Chemotherapy drugs are excreted in small amounts in the urine, faeces and saliva of patients receiving treatment.

Whether these small amounts of chemotherapy drugs, or their metabolites, can impact our health is not yet known. The drugs are, however, designed to damage cells and it is sensible to minimise human exposure until more is known. Children and pregnant women should take particular care to avoid contact with chemotherapy drugs or their metabolites. Children and pregnant women should also not handle any oral chemotherapy medications.

If your pet urinates or defecates in the house wear gloves to clean the area. Clean with disposable absorbent towel taking care not to splash urine when cleaning as this may aerosolise any drug or metabolites present. Use household cleaning product to clean the area and then dry with disposable absorbent towels.

Cats should have litter tray liners that allow for the entire contents of the tray to be disposed of once soiled.

Avoid contact with saliva by discouraging licking and washing skin if unexpected licking occurs.

If you are administering oral chemotherapy medications at home always wear gloves to administer treatment and give medications whole (do not split/crush/open capsules).