In the US you wouldn't have any problems claiming a disability with the trick knee. Not sure about the dogs, though I don't know how you Aussies regulate such things. I suspect you'd have to satisfy the relevant bureaucracy that the canines were "service dogs" that you couldn't function without. Since you're not blind and still have most of your mobility, that might be difficult.
Interesting vid. What had they treed, at the end of it?