How much benadryl do I need to give a 50 pound dog if I suspect that he has encountered a bufu frog to give me time to get him to a vet several minutes away? My other small dog almost died because of one, this time I would like to be prepared. I was a pathologist. Is there a better treatment that I can buy from the pharmacy. I keep an epi-pen for my son here always. I'm not sure if the dose prepared for the 200 lb child would be good for the dog. HELP. I also have benadryl on hand.