For treatment of intestinal worms, mostly mites, some lice, also include mange. The medicine is not effective in the elimination of ticks, flies, flukes, or fleas. Because the eggs & larvae on the floor will mature and come back to the host.Effective against larval heartworms, but not for adult heartworms, though it may shorten their lifespan. The dose of the medicine must be very accurately measured, due to it's highly toxic in over-dosage. Sometimes administered with the combination of other medications to treat a broad spectrum of animal parasites. Some dog breeds (like especially the Rough Collie, the Smooth Collie, the Shetland Sheepdog, and the Australian Shepherd), although have a high incidence of a certain mutation within the MDR1 gene; the affected animals are particularly sensitive to the toxic effects of Ivermectin. Clinical evidence suggests kittens are susceptible to Ivermectin toxicity.