yeah, I agree. I have a small yorkie too. He's 1 1/2 yrs and also just 4.5 lbs. I live on the second floor and he always runs up and down the stairs at least 3 times a day, and he jumps on every soft piece of furniture in the house. he even jumps off our bed which is really high (that's the only think i worry about cause i don't want him to break anything if he lands wrong). But as far as just jumping on and off the couch, i don't think that will affect him until he gets much older, and as they age, their bones get weak reguardless how playful they were when they were young. to sum it up, I don't think you have anything to worry about!
