Sounds like he may have put something out. You could try taking him to a Reiki therapist, or some other sort of 'dog putter righter' - think you may be able to find one by googling, unless you know anyone with greyhounds who usually know someone. If you're reallly lucky your vet may know someone or be able to do it, but some vets don't believe in all that hokus pokus stuff. I had a dog run into by one of the others, he was slam dunked right into his side and his back was almost like a banana and one session with the healer and he was right as rain.