Benadryl is used to treat allergy. This drug has not approved by FDA for animal use. Only vets can prescribe it legally. So, don't use this medicine in your puppy without supervision of vet. However, recommended oral dose of Benadryl in dogs is 0.5-2.0 mg per pound or 1-4 mg per Kg body weight for 2-3 times in a day.
