Does your dog get allergy shots?

One of our pits is allergic to everything. Having american pit bull terriers growing up and as an adult, I have dealt with allergies, but NONE as bad as these. She's a blue fawn rescued from the shelter at 8 weeks and the only one in her litter who got a home. We have spent thousands on her already. We had allergy testing done because she was really suffering. The testing showed that she was allergic to almost everything (every kind of grass, multiple kinds of trees, pollens, dust, mold). She suffers year round being a so cal dog because we don't have seasons, but it gets worse in the spring and summer. During the winter you wouldn't really know she has allergies. We have her on antihistamines daily and steroids occassionally but the specialist had recommended allergy shots for her last year. My husband was skeptical and didn't want to take her back. I'm concerned about the long term affects of steroids on her (she's only a year and a half now) so I've been pushing him for allergy shots. I think with a little more pushing, I may have him agreeing to it. The specialist did say that she might grow out of it on her own, but the likelihood of that was slim. He felt that a few years of allergy shots could save her suffering in spring/summer and she would likely be off them in a few years. Has anyone had their dogs on allergy shots? The cost doesn't matter to us because we will always find way to get the money. I just wanted to know if anyone had experience with them either negative or positive?

Thanks in advance!