Depends on what you consider major or minor...
Turbo's been battling a hip strain for 6 months now. We're on weekly PT which is kind of a pain in the butt, but he doesn't seem to be in major discomfort and it has not affected the quality of his life in any meaningful way (except he really, really, really, really wants to run and is forbidden!). We *might* have an autoimmune problem going on, but I highly doubt it. We go to a specialist on 6/23, but as I understand it, must autoimmune disorders are controlled fairly easily, with the exception of occassional flare-ups.