Health and Safety Notes for Owners of Chemotherapy Patients

Chemotherapy medications for pets can pose risks to humans due to their potential mutagenic and carcinogenic properties.

Research Authors


Pets undergoing chemotherapy will excrete small amounts of the drugs in their bodily waste for 3-7 days following treatment, requiring precautions when handling the waste. Guidelines include wearing disposable gloves, thoroughly washing hands, using child-proof storage for medications, and avoiding contact with treated animals’ excreta. Pregnant women, those trying to conceive, and breastfeeding women should not handle the drugs or contaminated waste.

Anyone in contact with chemotherapy should take precautions

Most chemotherapy medications kill cancer cells by damaging DNA or interfering with normal cell replication. Because of this, many chemotherapy medications are potentially mutagenic (can cause DNA mutations) or carcinogenic (can cause cancer).  The biggest risk is to whoever prepares and administers the chemotherapy medication (usually the team at the vet clinic) as they are handling the most concentrated forms of the medications and handle them most frequently.

However, animals who have been given chemotherapy will excrete small amounts of the chemotherapy medications in their stools and urine for 3-7 days following each treatment. The risk from your pet at this time should be minimal.

Reducing your exposure

  • On the day your pet is given the drug and then for 7 days afterwards, all bodily waste (urine, faeces, litter), blood, or vomit should only be handled while wearing disposable gloves. Seal the waste in a plastic bag and then place both the bag and gloves in the regular trash.
  • Solid items should be removed with gloved hands and double-bagged in impermeable disposable bags for household wastes.
  • Liquid wastes should be blotted dry. The area should be cleaned with dilute bleach once gross contamination is removed.
  • Although it is unknown how much drug is found in the saliva of treated animals, do not allow treated animals to lick human skin while receiving chemotherapy treatment.
  • Wash your hands after handling your pet.
  • Do not allow your dog to urinate or defecate in areas where children play.
  • Plastic litter tray liners should be used for cat litter trays as they allow easier cleaning.
  • Any soiled soft items (eg, bedding, towels, toys) should be washed twice, separately from other laundry, and ideally bleached.


Keeping the whole family safe

  • People who are pregnant, attempting to conceive, or breast feeding should not be tasked with drug administration or cleaning of any patient excreta.
  • Interaction with children in the home should be supervised, avoiding contact with excreta, and with thorough hand washing afterwards.
  • If inadvertent direct contact with contaminated urine or faeces of a patient occurs, the skin should be rinsed with water and thoroughly washed using dishwashing detergent.

**If you have any concerns about the risk to your health you should discuss them with your normal healthcare provider**

If chemotherapy has been dispensed to give at home

  • Children and pregnant or breastfeeding women should not handle chemotherapy drugs. If you are unsure, please discuss this with the oncology department.
  • Store your pet’s drugs in a child-proof container, and in a safe place out of the reach of children or pets. Some drugs require refrigeration.
  • Wear disposable gloves to handle the tablets/capsules and wash your hands after use.
  • Tablets must never be broken or crushed, and capsules must never be opened. You may find it easier to administer drugs in a tiny bit of food.