Thank you lovelabs. What kind of treatment can they give if your pup does have a reaction to it like yours did? I mean once the pup is vaccinated the damage is done, correct? My gut instinct is to stay away from it but my son wants to do it because our golden retriever had Lyme, poor guy. Gee 30% effective, of course the vet did not tell him that. Thank you for your reply. D