Sorry, but are you serious?
From my experience of the surgery and rehab I think it’s silly that animals are even offered this… sorry, their owners are offered it. Having a torn ACl doesn’t stop you doing 90% of activities, doesn’t hurt except when your knee actually gives way.. and when that happens you soon learn to hold back. Dogs are smart enough to do the same!!!
The “clicking” is more likely coming from damaged cartilage. Mine stopped after a year or so.
The surgery is going to cause a hell of a lot more distress and suffering than the lack of an ACl.