How much Benedryl per pound can you give a puppy?

Dogs and cats can't handle the same amount of human medication as humans can. Yes 1mg per pound with the dog, but this goes for pill version not liquid. Liquid has to go by the density of the liquid you are giving.

I have a 55lb dog and liquid benadryl would be no more than 1/4tsp MAX for this size, and that's almost too much.

The above is not accurate.. Standard dosage for dog is is 1 mg of benadryl per lb. There are 12.5mg of bendarly per 5 ml(teaspoon). Check with your vet first, but you can give 55lb dog 4tsp of liquid Children's benadryl. 1/4 tsp won't help.