Ivermectin isn't good for cats, it has to be an extremely low dose. I dodn't know that and gave my cat a lick of the apple flavored "Horse Paste" and she went kinda lame almost parylized she was very weak and couldn't move with any coordination. She got better in about three days, and now she is very fat. IDK if she is fat because of that indecent but she's a porker. I didn't know before I gave her a a little off the tube, A microgram is 1/1000 of a milligram. So a super small amount.
https://www.cuteness.com/article/ivermectin-dosages-cats
Ivermectin dosage for cats
The recommended dosage of ivermectin for cats as a heartworm preventative is 24 micrograms per kilogram of body weight by mouth every 30 days. Heartworm preventatives are prepackaged in the correct amount based on the size of the cat. Other formulations of ivermectin shouldn't be used.
Before a cat is prescribed heartworm preventatives, their veterinarian will need to perform a heartworm test to ensure that they don't already have the parasite. Giving ivermectin to a cat with heartworm disease can cause the worms to die, leaving cats with a dangerous anaphylactic-type reaction. Cats with heartworm infections may also need to have other diagnostics done, such as chest X-rays and an echocardiogram. Heartworm can lead to lung disease as well, and if a cat is found to have lung disease, they will also need to be prescribed medications to treat that.
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 ear mites. However, veterinarians are more likely to prescribe topical eat mite products for cats instead of injectable ivermectin. A high dose of 400 micrograms per kilogram of body weight administered subcutaneously has been used to cure feline mange, but this dose can cause toxicity in some cats.