What is Ivermectin?

• A. A monthly heartworm preventative for dogs marketed as Heartguard-30.
• B. A dog antibiotic for skin infections.
• C. A veterinary vaccine for heartworm.
• D. A flea treatment for cats.

Answer: (A)

Ivermectin is a broad-spectrum antiparasitic used in dogs as a monthly preventive against heartworm disease. When given on a regular monthly schedule, it kills the larval stages of heartworms that are transmitted by mosquitoes, preventing development into adult worms that can damage the heart and lungs. The Heartguard-30 product is one common brand that delivers ivermectin for this purpose. It is not an antibiotic for skin infections, not a vaccine, and not a flea treatment, which is why the other options describe different drug roles. While generally safe at preventive doses, some dogs with certain genetic traits can be sensitive to ivermectin, so proper dosing and breed considerations are important.