You can give your dog Benadryl (diphenhydramine) two to three times a day, typically every 8 to 12 hours, depending on your dog's symptoms and your veterinarian's guidance

. The usual dosage is about 1 mg of Benadryl per pound of your dog's body weight per dose. For example, a 20-pound dog would receive about 20 mg per dose, given two to three times daily

. This corresponds to roughly 2 to 4 mg per kilogram of body weight, as per veterinary manuals

. It is important to:

• Use only Benadryl products containing diphenhydramine without other active ingredients like acetaminophen or alcohol

• Consult your veterinarian before starting Benadryl, especially for puppies, pregnant or nursing dogs, or dogs with other health conditions

• Avoid time-release capsules and be cautious with liquid forms that may contain harmful additives like xylitol

• Monitor your dog for side effects such as drowsiness, dry mouth, or urinary retention, and seek veterinary help if you suspect an overdose

In summary, Benadryl can be safely given to dogs two to three times daily at about 1 mg per pound of body weight per dose, but always under veterinary advice to ensure safety and proper dosing.