Chemotherapy Drug Poisoning in Dogs and Cats

What are chemotherapy drugs?

Chemotherapy medications are primarily used to treat cancer in people and animals. They can also be used to treat autoimmune disorders, certain blood disorders, or as immunosuppressive agents in organ transplant recipients.

Many chemotherapy drugs target and kill rapidly dividing cancer cells, preventing them from multiplying out of control.

Normal, healthy cells that grow quickly can also be damaged. Newer forms of chemotherapy may just target cancer cells, minimizing potential damage to healthy cells.

What causes chemotherapy drug poisoning in a dog or cat?

Chemotherapy medications are available in injectable, oral, or topical formulations. Animals may be exposed to these medications in the home by ingesting them if they are dropped or spilled, by licking a topical medication after application, or by chewing into the medication container.

What are the signs of chemotherapy drug poisoning in a dog or cat?

Signs of chemotherapy drug poisoning vary, depending on the type of chemotherapy drug and the species exposed. 

• Stomach upset is common and may include decreased appetite and abdominal pain. 
• Some drugs may cause neurological signs such as tremors and seizures.
• Bone marrow damage may develop days to weeks after ingestion, resulting in low numbers of white blood cells, red blood cells, and/or platelets. 
• Bone marrow suppression puts pets at an increased risk of infections. 

Chemotherapy medications can also damage other organs, including the liver, kidneys, heart, pancreas, and lungs.

How is chemotherapy drug poisoning treated?

As with all poisonings, early intervention is key to successful treatment. Call your veterinarian or Pet Poison Helpline, a 24/7 animal poison center, at 1-800-213-6680, as soon as you realize your pet has been exposed to a chemotherapy drug. Your pet’s veterinarian may induce vomiting to help remove the toxin from the system before it is absorbed and may also give medical-grade activated charcoal to minimize absorption of any remaining toxin from the gastrointestinal tract.

Supportive therapy includes fluid support and medications to treat the pet’s clinical signs. Hospitalization may be needed. Bloodwork may be done to monitor organ function and blood cell counts. To treat bone marrow suppression, your pet may need blood transfusions, drugs to stimulate red blood cell production, and antibiotics.

Pet Poison Helpline, an animal poison center based out of Minneapolis, MN, is available 24/7 for pet owners and veterinary professionals that require assistance treating a potentially poisoned pet. The staff provides treatment advice for poisoning cases of all species, including dogs, cats, birds, small mammals, large animals, and exotic species. As the most cost-effective option for animal poison control care, Pet Poison Helpline’s per-incident fee includes follow-up consultations for the duration of the poison case. Pet Poison Helpline is available in North America by calling 800-213-6680. Additional information can be found online at www.petpoisonhelpline.com.