Flea, tick, and heartworm preventatives are extremely important. In fact, Tennessee ranks among the top 5 states in the nation for heartworm infection. Not only can the infection be detrimental to your pet’s health, treatment is very costly and hard on your pet’s body. Flea and tick preventatives help to prevent tick borne diseases, flea allergies, and complications, such as flea anemia, as well as some intestinal parasites.