Major Uses

Doramectin is an avermectin antiparasitic agent that is often used to treat and control various endoparasites and ectoparasites in cattle. It is also used to treat and control gastrointestinal roundworms, lungworms, mange mites, and sucking lice in swine. The injectable form has shown useful in treating various nematode and arthropod parasites in dogs and cats.

Common Precautions

Doramectin should not be used for treating demodicosis or spirocerosis in dog breeds susceptible to the MDR1-allele mutation. Testing has shown a higher risk for toxicity in these breeds.

Adverse effects caused by doramectin are rare. Intramuscular injections have a greater chance of causing injection site blemishes than other types of administration. Possible negative side effects that have appeared when treating dogs for demodicosis include pupil dilation, blindness, lethargy, and coma.

Doramectin 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 or any alarming symptoms occur.


Doramectin should be kept in a light resistant, childproof container at room temperature. The drug should not be exposed to light and it should be stored out of reach from children and pets.


A typical dose of doramectin used for treating generalized demodicosis in dogs is .6 mg/kg once a week. For treating feline demodicosis, a typical dose is .6 mg/kg once a week. For cattle, a typical dose is .2-.5 mg/kg. For swine, a normal dose is .3 mg/kg. Should a scheduled dose be forgotten, it should be administered as soon as possible. If the next scheduled dose is near, the missed dose should be skipped and the regular medication schedule should resume. 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.