poodle hop

Question
We have a 1.5 year-old miniature poodle.  He developed a weird hope about two months ago.  He hops on his right rear leg only when we walk him outside.  He is otherwise super-energetic and doesn't display this hop when he is off the leash and runs around. His vet couldn't find anything wrong with him and the x-rays showed no evidence of structural problems.  Any ideas?

Answer
Hello,
I have a fairly good idea of what may be going on with your dog.  
To get conformation of what he might be doing though, I will need a few questions answered.  

Does he do this everytime he is walked and does he do it throughout the entire walk?  

What do you do when he starts hopping?

Who walks him, (you mentioned We in your question) so do you all three go for a walk together all the time, or do you sometimes take him with just one or the other of you?

Have you taken him other places (such as Downtown, or to the park) or do you just walk him around in the neighborhood and does he hop on his leg when walking elsewhere?

Other than hoping on his leg, does he seem to enjoy the walk, ie does he look around at things or stop to potty, sniff the ground and do regular things that a dog does, or does he concentrate on hopping the whole time?

Does he have any other things that he does while walking such as pulling back on the leash or refusing to walk?

Answer these questions for me and I will give you what I suspect is going on with him.  

Thanks for your time and I will talk to you soon,
Kim
You can either get back to me in the form of another question on this site, or you can e-mail me the answers at Topkdog@webtv.net and I will e-mail you back.