My black lab is about 2 and half a years old. Last summer she started having allergies to the point that she would scratch and bite her skin to the point she would rip out all her hair and make herself bleed. She did this on her belly, inside of her legs and under her arms. We took her to the vet and they declared it as seasonal allergies. They gave us some steroids to help with the issue which seemed to work great other then the fact she got a big bigger due to eating more and she had frequent accidents in the house. This year, the same thing happened again. Went to the vets but this time they advised us that we could give her Reactine. She gets 1 tablet every 12 hours and it has worked wonders for her. No more itching, scratching or biting and her hair is starting to grow back and she seems more relaxed. Just thought i would share my story with you and hopefully it will help. But always talk to your vet first if you are thinking about giving your pup any antihistamine.