DAS recommends all dogs and cats be on monthly flea and tick preventative. Fleas and ticks can carry a variety of diseases that can cause illness in both pets and humans. DAS strongly recommends ensuring your dogs and any cats exposed to the outdoors are on heartworm preventative. Talk to your veterinarian about the best option for your pet. Heartworm treatment is very expensive – save money and ensure your pet’s health by keeping them on heartworm prevention.