Bamm has the collie/herding breed sensitivity towards certain Heartworm treatments. The only one ive ever been able to give him was Interceptor but from what I've been hearing they closed their production down. Not sure if its a temporary or permanent discontinue of Interceptor, but now I have no clue what I can give Bamm and don't know much about other Heartworm preventatives. The one our vet uses has Ivermectin in it so he can't use that. Do you guys know of any other brands that are ok for dogs that have that collie sensitivity towards Heartworm preventatives?