I thought of something else that you might want to check out, and then I'll give you a break with all these posts. Have you ever heard of Dr. Karen Becker? She is not in Florida. She has a lot of info about how to help your pets. I'm including a link (that I haven't watched) to a video she has on allergies - she has more than this one.
https://www.youtube.com/watch?v=6s3DVkDhBXw
And here is one she has about the best and worst foods for your pet. I haven't watched this one either. I'm not sure if this will help but just in case you want to look at it here it is.
https://www.youtube.com/watch?v=FZ-Srqs4kc8