Ivermectin Dosages for Cats

By Elizabeth Tumbarello

Ivermectin is a drug used as both a preventative and a treatment for certain ailments in cats. Oral and topical solutions of ivermectin are available from your veterinarian. In case of overdose or side effects, seek emergency veterinary care for your pet.

Primary Use

Ivermectin was approved in 1996 by the U.S. Food and Drug Administration (FDA) for use in cats as a heartworm preventative. Under veterinarian guidance, it may be used for other, off-label purposes as well.


The recommended dosage of ivermectin for cats as a heartworm preventative is 24 micrograms per kilogram of body weight.

Other Uses

Ivermectin has been used in veterinary medicine to treat ear mites and mange. In these cases, the drug is given via subcutaneous, or under the skin, injection.

Other Dosages

A single dose of 200 micrograms per kilogram of body weight given as a subcutaneous injection is the standard for use in the treatment of earmites. A dosage of 400 micrograms per body weight administered subcutaneously has been used to cure feline mange.

Signs of Overdose

If an overdose of ivermectin has occurred, serious side effects may result, including blindness, ataxia or lack of coordination, and death. Lethargy, lack of appetite or thirst, and seizures are also signs of an ivermectin overdose.