is he on a heartworm preventative like interceptor or heartguard? these are monthly dewormers that take care of heartworms, as well as the common types of intestinal parasites.
i do not know why your dog got worms again unless they were never really gone or the infected poop was never picked up in the backyard. He could also pick them up from wild animals pooping in your yard.
__________________ Kellie  and  Morgan |