Sounds interesting... I think hydro therapy would help as it will allow the joints to move without putting pressure on them. You might also want to look at canine massage- i am currently studying this and it is early days but there are some fab success stories from it in such cases ...

The collars seem interesting, never really looked into them .... is this something you could use as preventative - i have a DDB and worry about her joints in later life - she is only a pup now but would do anything to make sure she doesnt suffer when she gets older