[header] How to give a dog benadryl [title] Dose the dog correctly. [step] Generally, you give a milligram per pound of dog. You can give it every 8 hours or so. 
So if your dog weighs 14 pounds, you can give 14 milligrams of benadryl every 8 hours. However, it's always best to check with the vet for an appropriate dose.