My second greyhound, Keno,had laryngeal paralysis. I suspected it from the symptoms I read online, but my vet said he'd never seen or heard of it in a greyhound and felt it was allergies and treated it as such. I'm not sure it was related to the LP, but about a year later he had started having intermittent lameness and fever and enlarged lymph nodes. He was tested for TBD and lymphoma, both negative. Then at 2:00 am on New Year's Day 2007 he couldn't breathe and I rushed him to the emergency vet. I thought he was going to die before I got him there. It was horrible. He was sedated and intubated just in time to save his life. They confirmed he had bilateral LP and unspecified neurological issues. He was a few weeks short of 13. When they removed the tube, he couldn't breathe and became very distressed, so I made the decision to let him go.
I'm sorry to hear you've gotten this diagnosis, but many dogs live normal lives after a tie back. Sending good thoughts your way. Oh, and I would definitely get a surgical consult from a vet experienced with the tie back surgery.