Rabbit Elons - Where to Get Them Can a 50-pound dog Use 2 Benadryl According to the Merck Veterinary Manual, the safe dosage is 2-4 milligrams of medication per kilogram of weight, or 0.9 to 1.8 milligrams per pound. Depending on your dog's condition, you can give this dosage twice https://www.pinterest.com/pin/1097400634177948024/