We have a 10 year old Chow Lab mix that thinks he's a pup most of the time. When we go camping in our TC (we have the Torq-Lift Gow steps), we put a piece of masonite between the top step and the camper so he don't slip into the void.
When he gets in and out of our Suburban my wife has a set of wooden steps she uses to assist him but I still get to lift his butt on ocassion even though I get that 'I might bite you look'...lol
He gets a cold laser treatment monthly, helps a lot plus I walk him at least 1.5 miles daily.
Like I said, 10 going on 2.