Isn't this site the BEST!! I love when we all have a question so many Saint Parent respond. We have given Cassie benadryl as well with good results, I checked with the vet and he said it was fine I think he said 10mg for every 10 pounds, I am not 100% sure of that. One night Cassie had a bad reaction to a shot and she huge hives all over her entire belly, she couldn't stop biting and licking herself- she was literally losing it. We gave her the benadryl(alot, I don't remember how much) and it helped, it also knocked her out. My husband had a great idea, we got a kitchen trash bag and filled it with ice and bit of water, tied a knot in it, and laid it in a towel on her belly and it calmed her down and I think it made her feel better. Everyone sounds on the right track with a food allergy. By the way we bought the cheapest off brand we buy. Recently she had her first "hot spot" we took her in, and a spray,antibiotics, and a shave did the trick, she completely healed. Good luck!!!