Hi,
welcome to YT. Sorry to hear about Leo's problem. I've been blessed (so far) to not have this problem, but I would advise getting a second opinion, perhaps from a specialist before going through with the surgery. My vet checks my kids knees every time they come in. Your vets comment that vets only check for the problem after there is lameness would cause me a little concern. Good luck with whatever you decide and please keep us updated.
Oh! And post some pictures of your cutie when you can!!
