For the well being of your pet he/she needs to be on heartworm preventative all year round. We recommend Iverhart Plus or Max as our primary heartworm preventative because of cost savings. Heartgard Plus is always available for those clients or pets that prefer it. Both of these products protect your pet against heartworms and the most common intestinal parasites. Annual heartworm tests and fecal exams are important to ensure a good quality of life for you and your pet.