Since the horse is retired, you may not want to go through this, but I had my horse allergy tested at a university vet clinic (not a blood test—the dermal test is considered the gold standard). They use the results to make a custom “serum” for your horse. Then you give them allergy shots (on a schedule the vet provides) starting out with more frequent doses of small amounts, highly diluted. You move toward less frequent, higher concentration serum. You do have to try it for at least a year to know if it’s working or not. However, outside of the initial testing, the shots aren’t that expensive–and very easy to give (tiny amount, subcutaneously). For a while I was getting the Platinum allergy supplement an it was considerably more $$$ than the shots. And the shots really helped my mare! She is sooo much more comfortable in the spring/summer. Her eyes used to get swollen and itchy and she was constantly rubbing her eye on my arm (and looking miserable!) Last summer—her eyes were clear and not itchy. I had tried some antihistamines for her before I went to the shots—but they never worked very well.
