[megooego]

Originally Posted by bonbon

Yes, it really is necessary for them to be tested every year. The HW prevention can be deadly if it's given to an animal with heartworms so it's best to have them tested annually just to be safe.

I thought that was a myth.. I have heard that when a dog contracts the disease, the recommended first part of heartworm treatment is to give heartworm meds (Heartgard).

I think you should still have the test done though.
I think most vets require it, actually.