Ivermectin is the most used veterinary antiparasitic worldwide. There are thousands of generic brands for livestock, horses and pets. It is used in all imaginable formulations: pour-ons, feed additives, drenches and injectables for livestock, oral pastes and gels for horses, tablets, pills, etc, oral suspensions and injectables for pets, etc. It is both used alone or in combination with many other active ingredients.

It is effective against roundworms (gastrointestinal, respiratory, renal, in the skin, etc.) and depending on the delivery form and the dosage also against a number of external parasites such as lice, mites and various myiasis. However, it is ineffective against tapeworms and flukes, and at the usual use recommendations it doesn't control e.g. fleas, stable flies, mosquitoes, horse flies, multi-host ticks (e.g. Amblyomma spp, Dermacentor spp, Haemaphysalis spp, Ixodes spp, Rhipicephalus spp, etc.) and several other external parasites. In the last years it has been increasingly used in many countries against cattle ticks (Boophilus = Rhipicephalus microplus) and horn flies (Haematobia irritans), but efficacy against these parasites is often mediocre and insufficient.

The following table reproduces some usual dosing recommendations for ivermectin for cats issued by manufacturers or documented in the scientific literature. They may not be approved in some countries.

Dosing recommendations for IVERMECTIN: CATS
Delivery Parasites Dose (against ivermectin-susceptible parasites)
Oral Ancylostoma spp 0.01-0.34 mg/kg
Oral  Toxocara cati 0.3 mg/kg
Oral  Dirofilaria immitis: prophylaxis 24-75 mcg/kg
Oral Notoedres cati 0.2 mg/kg every 7 days during 6-8 weeks
Oral Otodectes cynotis 0.2-0.4 mg/kg, rep after 2 weeks
Oral Sarcoptes scabiei 0.2-0.4 mg/kg, rep after 2 weeks
Subcutaneous Aelurostrongylus abstrusus 0.4 mg/kg
Subcutaneous Ancylostoma spp 0.01 mg/kg
Subcutaneous Toxocara cati 0.2-0.3 mg/kg
Subcutaneous Cheyletiella blakei 0.3 mg/kg, rep after 35 days
Subcutaneous Demodex spp 0.3 mg/kg 1x/week, during 3 weeks
Subcutaneous Otodectes cynotis 0.2-0.4 mg/kg, rep after 2 weeks
Subcutaneous Sarcoptes scabiei 0.2-0.4 mg/kg, rep after 2 weeks if needed
Subcutaneous Lice 0.2 mg/kg
Topical (spot-on) Toxocara cati 0.5 mg/kg, 2-4 treatments with 14 days interval
Topical (spot-on) Cheyletiella spp 0.5 mg/kg, 3 treatments with 14 days interval
Topical (spot-on) Otodectes cynotis 0.5 mg/kg, rep after 2 weeks

DISCLAIMER: Liability is denied for any possible damage or harm to persons, animals or any other goods that could follow the transmission or use of the information, data or recommendations in this site by any site visitor or third parties.

  • Click here to view the article on Ivermectin dose for Dogs
  • Click here to view the article on Ivermectin dose for Horses, Cattle, Sheep, Goats, Swine, Poultry, etc.

Dosing recommendations for antiparasitics depend on national regulations. National regulatory authorities determine whether a product is approved for a given indication, i.e. use on a particular host at a specific dose and against a specific parasiteCheck the labels of the products available in your country for specific information on approved indications.

In most finished products, efficacy and safety depend not only on the amount of active ingredient(s) but also on their formulations (i.e. the type and amount of so-called inert ingredients), particularly in injectables and in topical pour-ons and spot-ons. These inert ingredients can significantly affect the pharmacokinetic behavior (e.g. absorption through the skin or from the injection site, distribution within the body, spreading throughout the body surface, etc.). Generic products usually contain the same amount of active ingredient(s) as the original product, but often in quite different formulations. In many cases, the curative (therapeutic) efficacy of the different formulations is quite comparable, but the protective (prophylactic) efficacy that determines the length of protection against re-infestations may be rather different.

  • Click here to view the technical summary of this active ingredient
  • Click here to view the safety summary of this active ingredient
  • Click here to view the list of all technical summaries of antiparasitic active ingredients in this site.