2. Topical (Spot-on) Heartworm Medications
These heartworm medications are applied monthly to the back of the dog or cat’s neck, or between the shoulder blades on the skin. Not only do these preventives protect against heartworms but there are some with active ingredients that work to eliminate such things as fleas, ticks, mange mites, and roundworms. These heartworm preventives are toxic if ingested, so be sure to isolate your pet for a time after application — both to prevent your pet from coming in contact with children or other animals and to prevent them from rubbing the medication off on furniture, carpet, etc.