Happened with my lurcher, ran him too much one night (or rather didn't stop him early enough).
Dog was in vets for 4 days after, he'd gone blind, deaf etc, with hindsight I should have let him go, but ......... I didn't, and he really was never the same again, I'm not shy when it comes to conditioning, it's why I have dogs to spend time out with them, but my lurcher never seemed to get his wind back.
Hope you have better results than I did.