About The Author: Lorraine Shelton breeds and shows under the Featherland cattery name. She has a Persian breeding program specializing in chocolate and lilac, a small Selkirk Rex program, and a blossoming Turkish Angora program. Lorraine is a noted author, geneticist and line-chaser. This article is part of a series of articles she has written on health issues of interest to cat breeders which are published on the Fanciers Health Yahoo Group email list.
I've been getting lots of private requests for information on dosing ivermectin to treat ear mites, body mites and roundworms.
Can you tell me what the dose is? What strength of Ivermectin?
I recommend using the 0.27% swine formulation only. The dose is "one drop per pound" (0.05 ml per pound, 0.5 ml for an adult cat). If using the 1% solution, the dose is 0.1 ml for an adult cat, but must be carefully diluted to be accurately dosed in kittens. Diluting one part 1% Ivermectin to three parts mineral oil will create a solution that can be dosed topically in the same amounts as the 0.27% solution. One source for purchasing Ivomec 0.27% online is Jeffers Livestock.
Ivermectin can be injected or given orally, but it is also well absorbed through the skin. Personally, I apply the dose directly into the ear canal. This causes the cat less pain than the injection and eliminates the risk of injection site problems, such as hair loss or abscess.
I like to wait until the kitten is 8 weeks old, although ivermectin has been proven to be safe in random-bred kittens 4 weeks old and up. It is also safe to use in pregnant queens, although I prefer to wait until the last trimester of pregnancy.
The dose for 1% ivermectin is 0.05 ml for a kitten weighing at least four pounds. This is a VERY tiny amount (one drop), so make sure your syringe has a total volume of only 0.5 ml (insulin syringe). Getting ivermectin to draw into an insulin syringe is an ordeal in itself (it is a very viscous solution) If kittens under that weight are to be dosed via injection, the solution must be diluted in propylene glycol. I recommend diluting one part ivermectin with three parts propylene glycol and then injecting at a rate of 0.05 ml per pound.
Personally, I prefer to dose ivermectin topically rather than by injection. This drug does sting when injected. When used topically, the drug can be diluted in mineral oil instead of propylene glycol.
topically in the ear canal too?
Yes, ivermectin is absorbed very efficiently through the skin into the bloodstream.
Ivermectin treatment should be repeated in 2-3 weeks to catch life stages that were not killed by the first treatment. Prevention of reinfection is important and can be accomplished by cleaning the environment thoroughly and treating all cats in the cattery at the same time. Mites do not live for significant amounts of time in the environment, so treatment of the carpet, scratching posts, etc. with an insecticide is not necessary.