I had a toy poodle years ago who had a luxating patella. The first time it happened he was boinging up against the sliding door asking to go out. After a big yelp he wouldn't put that leg down. I took him to the vet and he showed me how to slide it back into place but advised that surgery would correct it, if it occurred too often. Long story short, he had the surgery and there was never a problem after that. I bought Pumpkin from a couple whom I now realize were backyard breeders. Neverthless he lived to be 17 years old and was the sweetest little boy.