The vet told me to start Jaxson my 3lb 3month old male yorkie on heart guard & mark it on the calendar so every month on the same day give it to him! I cut the heart guard chewie up & gave it to him after we got home from the vet. He was happy & running around like normal. He had a full workup though cause I wanted to make sure he was healthy & he was so as long as your vet says it's a-okay to give him the whole chewie then I see no problem.
Good luck!