Heartgard Plus Chewables Review

I have a 6-year old Shih Tzu which I've had since he was a puppy.  I want him to be a around for many more years.  He loves his HeartGuard and can recognize the box right away.  I don't have to say anything.  As soon as I pick up the box, he sits next to me with his tail still wagging. 

Because my dog's teeth are crooked, he has a hard time chewing and tends to swallow most things.  For this reason, I break it into little pieces (which is not very easy to do).  My vet recommended HeartGuard even though my dog is in the house most of the time.  Because he's housebroken, the vet suggested I put him on HeartGuard to be on the safe side.  Better safe, than sorry.