I need help badly to control my dog's hives. Let me give you the history. Tuesday morning she woke up completely swollen. I took her to the vet and she was given a Benadryl IV and a steroid shot. She was fine and hive free by the afternoon and all day Wednesday. Thursday she woke with the same thing. I've been giving her 50mg pills of Benadryl given to me by the vet, but they only control her hives for about 2 hours. She's breaking out with hives 3-4 times/day! I'm so scared that I'm going to overdose her on Benadryl. She's scratching her ears raw and her poor face is so swollen she can barely open her eyes. I spoke with the vet again, and they are unable to see her today so she's going back in Monday. I don't know what to do in the meantime. It worries me. She has heart and lung conditions on top of this so u can see why I'm freaking out!!! Any suggestions or advice would be helpful. Thank you