How Do We Tell the Difference Between Heartworm Resistance and Other Causes of Lack of Efficacy?

With the emergence of anthelmintic resistance to medications used to prevent heartworm disease caused by Dirofilaria immitis in dogs, there is a possibility that dogs reportedly on heartworm disease preventives test positive for heartworm antigen. This presentation will examine how we can tell the difference between a dog that has resistant heartworms and one that has heartworms because of other causes of lack of efficacy, such as lack of owner compliance or incorrect dose administration. The talk will also discuss anthelmintic resistance in canine heartworm and considerations for preventing infections with resistant heartworms.