My Butch also had knee problems. I can see in the one pic of Poochino that the muscles on his leg are slight. Butch came to me with small back legs and small rearend. After he had knee surgery, his muscles "muscled" right up and became very strong. I had them both done at the same time. He looked pretty cute in his casts. He had his pallet in the living room and sat there like a King while I catered to his every need.