Question: how much benadryl can you give a dog to sleep?
Answer: A recommended therapeutic dose for diphenhydramine in dogs is 2 to 4 mg/kg BW for the treatment of allergies or mild sedation prior to stressful situations. For an 18-kg dog, this would equate to 36 to 72 mg diphenhydramine or 1 to 1.5 tablets.