The correct answer is Ivermectin. Anthelmintic drugs are antiparasitic drugs that kill or stuns the parasitic worms and expel them from the body of the animal without causing any major damage to it. If the Anthelmintic drug kills the parasitic worms, it is known as vermicides. If the Anthelmintic drug stuns the parasitic worms, it is known as vermifuges. Ivermectin which belongs to the avermectin family is the most commonly used anthelmintic drug to prevent heartworm in dogs and cats. ?Additional Information Meloxicam is an anti-inflammatory drug used to treat inflammation, pain, and fever in dogs and cats. Oxytetracycline is an antibiotic drug used to treat diseases related to respiration and the gastrointestinal system in dairy cattle. Potassium permanganate is used to treat skin infections and thrush in animals