Benadryl, or diphenhydramine, can be safe for dogs when used appropriately under veterinary guidance. It is commonly recommended for treating allergies, itching, and mild cases of motion sickness. Elly Anderson, a long-time pet owner, also states that it is safe to administer Benadryl. She mentions having a 25-pound Boston Terrier with allergy issues and explains that she provides her dog with half a pill in the morning and half in the evening. She also notes that sometimes a single half-pill is sufficient to help with her dogโs allergies. While Benadryl is generally considered safe, adverse effects may occur, including drowsiness, dry mouth, and urinary retention. Certain medical conditions or medications your dog may be taking could also interact negatively with Benadryl. Additionally, formulations containing additional ingredients, such as decongestants, can be harmful to dogs and should be avoided. Never give your dog Benadryl without consulting a vet, especially if your dog has a pre-existing medical condition or is pregnant.Reference: https://www.quora.com/Is-it-safe-to-give-an-itching-dog-Benadryl/answer/Elley-Anderson