Hey Pheets – sorry to hear that your boy is not feeling well. I’ve been there with my own horse’s Lyme as well as my own, so I know how frustrating and exhausting it can be. Neither my horse’s nor my condition was chronic, so I don’t have any personal experience to offer there, but I did find an Ask the Vet blog that you may want to check out and discuss with your veterinarian: http://blog.smartpakequine.com/2009/07/help-for-a-horse-with-lyme-disease/
Good luck, and keep us posted on how he’s doing!
Rider, Runner, Stuff-Riders-Say-er, SmartPaker