*Disclaimer* I'm not a vet, but this is my .02...
I believe it's iether an environmental or food allergy or combo of both. BARF/RAW is something you can do at home yourself. No need to order online, unless you just don't feel like dealing with it. Read these threads for help with BARF and RAW viewtopic.php?f=5&t=18048
the second link is a great source to help with transitioning to a RAW diet.
As for the hives
that you are seeing, there is another thread about a recent member that went through this. Maybe it will be of help to you? viewtopic.php?f=5&t=150081&p=1974804&hilit=Hives#p1974804
There are many other threads here dealing with hives
and allergies, as many of our dogs have them. One of mine has a few food allergies(Chicken mostly) and a Febreeze allergy that I have to be very cautious about. Just do some searches in the Health section and you will find tons of info.