If your veterinarian says it's okay, give your dog 2 mg of Benadryl per 1 kg (2.2 lb) of body weight, or follow your veterinarian's dosing suggestion. Repeat the dose every 4-6 hours while you need to keep your dog sedated. Do not exceed a dose of 4 mg of Benadryl per 1 kg (2.2 lb) of body weight every 4-6 hours.