If it rolls up into a ball, get out of render distance on a flyer or fast tame for a bit then come back it should normal then you can tranq it once or more if lucky, rinse and repeat. Their torpor drops at 2.4 per second, as long as you keep pumping tranqs in under 30-45 secs(more than enough time to render out and back) it should get knocked if it's health allows it