Hi , i have been told about Seraquin to help with Montys joints as he is a bit unstable on his back legs at times and was wondering if it is ok

It may help, it may not.  It's a joint supplement with a few things in.  It is one of the better ones so it may well do him some good, providing you follow the dosing instructions.  Get it online, not from the vet as the markup at the vet is massive.

However it's best to find out, if you can, exactly why he's unstable - if there's any pain involved then you'll need to get that controlled as well.

He seems happy in himself , eating well quite playful and still gets excited when he knows he is going for a walk .
Old age does not come alone !

Over the years i have had 5 roughs .all different blood lines and yet i have lost them all before they reach 11 ..

Just the way it goes i suppose even for my next one ..