is it a puppy. My Logan did the licking tongue thing when he was trying to lose a tooth, just like a little kid. Also my pup would all of a sudden yelp and then limp, this was caused by his growth plates not being closed yet (according to my vet) and it cleared up on it's own. Just a couple of thoughts.
But please have them call the vet just to be sure.
__________________  Ponyup Mom to LOGAN  |