[Morkie4]

It is my understanding that a dog is immune until six months of age so no heartworm meds are needed until they reach six months. I have all three of mine tested for heartworms every year at a clinic I take them to because they will not sell the heartguardplus if I don't. It is only $15for the test for each of them and then $34 for a year supply each. Well worth preventing heartworms. The clinic also gives them all the shots. So each dog costs me $78 through the clinic.............a big savings from my regular vet's charges.

I asked my regular vet that cares for the other needs of my dogs when they get sick about testing every year and he said that it is necessary that it is a "preventative" and the only way to know if they do not have them is to test! So I test!