6 days ago my mom was about to let my dog out to do his business and he got impatient and tried to run past her by squeezing himself between her and the patio door and I heard him yelp. He started walking holding his right hind leg up and when trying to put weight on it he yelped again. Since then he has been walking on only three legs. He only yelped when it first happened and since then he will stand on it, walk slowly on it, will get up on his back legs to say hi or ask for food, and he’s even jumped up onto the couch once but when he wants to run or walk fast he holds that leg up. He seems happy and doesn’t act like a dog in pain and me, my mom, and my brother have tried to work out his leg so we can see where the pain is but no matter where we touch there is no response from him. Nothing looks out of place either but obviously something is up if he won’t put weight on it most of the time. Anyone have any idea?