My Maggie had a severe reaction to a spider bite at 9 weeks. She'd just mastered going down the porch steps & plopped her paw straight down on a nasty fuzzy spider. She started yelping & her paw instantly swelled up. We took her to an emergenct vet, by then the swelling had spread to her poor little leg =( The vet gave her steroids & a couple shots of something or other. I had to give her Benadryl @ home for a couple days. She now chases bees & comes in with hives- more Benadryl for Maggie !!! We should buy stock in who ever makes the stuff =)