Major Uses

Vincristine is an antineoplastic that is used in dogs and cats to treat tumors. It is most commonly used in combination with other drugs for treating lymphoid and hematopoietic neoplasms. It may be useful by itself when treating transmissible venereal neoplasms in dogs. It is sometimes used in treating immune-mediated thrombocytopenia.

Common Precautions

Vincristine should be used cautiously in patients with hepatic disease, leukopenia, infection, or preexisting neuromuscular disease. Patients with hepatic disease should receive doses that have been reduced by half. It should be used cautiously in herding breeds and in dogs with the ABCB1 mutation. Vincristine may cause skin irritation and should be carefully administered to prevent this from happening.

Some negative effects of vincristine include proprioceptive deficits, spinal hyporeflexia, and paralytic ileus with constipation. It may also cause mild sensory impairment, peripheral paresthesias, reversible axon swelling, and paranodal demyelination. Small animals have been observed experiencing impaired platelet aggregation, increased liver enzymes, inappropriate ADH secretion, alopecia, stomatitis, jaw pain, and seizures.

Vincristine should not be used in animals with a known allergy or hypersensitivity to the drug. A veterinarian should be contacted immediately if an overdose is suspected, the symptoms of which can be slight anemia, leukopenia, increased liver enzymes, and neuronal shrinkage in the peripheral and central nervous systems. Other signs of an overdose can include weight loss, seizures, and general debilitation.


Vincristine should be kept in a refrigerator, stored at 35.6-46.4 degrees Fahrenheit in a tightly sealed, light resistant, childproof container. Children and animals should not have access to vincristine.


A common dose of vincristine used to treat dogs ranges from .5-.75 mg/m² during a one time injection. When treating cats, a typical dose is.5-.75 mg/m² every 1-3 weeks. Should a dose be forgotten, it should be administered as soon as possible. Should it almost be time for the next scheduled dose, the missed dose should be skipped and the animal's regular medication schedule should resume. No matter what, two doses should not be administered at the same time.

Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

This information is for general reference only and should not be used for the diagnosis or treatment of any condition of your pet. It's intended as a general reference, this information may not include all possible uses, precautions, directions, reactions (including allergic), drug interactions, or withdrawal times. Always consult your local veterinarian and have your pet examined for any advice concerning the diagnosis and treatment of your pet, including which products and doses are most appropriate. Any trademarks are the property of their respective owners. VetDepot is not a pharmacy. All prescription products are dispensed by our Pharmacy Partner. Article last updated 2/2014.