I have had my kingsnake for 9 years and have not had any problems until now. About 2 weeks ago I noticed that he cannot seem to swallow even the tiniest mouse. His tongue seems to be "stuck" in his mouth and his mouth looks strange. He is hungry and wants to eat, but when he tries to swallow the mouse he jerks his head to the side. If he gets the mouse into his mouth, he spits it back out, as if he cannot swallow it. I took the sanke to a vet yesterday and he said he could not determine the problem. Any ideas?