Cincy's mom is right. The injection only takes care of the heartworm itself, whereas the tablets cover everything except hookworm and whipworms. For that reason i will stay with the tablets. However before I became so educated on heartworm preventives I did have the vet to give the injection to my Patches. Having asked a few other vets I know they all say the pills are better and more effective as long as no doses are missed, and there is no longer a need for regular wormings for roundworms and such.

jaquetta