Hi, agree with everything in the above answer and would also like to add that it is good to keep your dog moving to ease stiff joints, aches and pains. Nothing excessive obviously due to his condition but controlled leash walks or a simple a walk around the house every few hours to prevent him from laying in one position for too long.
keeping your dog slim is also important due to the pressure exerted on his limbs! Ramps, or mini stairs onto the sofa would be good to prevent jumping (if they're allowed ofcourse). Lastly you could watch some YouTube tutorials on how to give soft physio therapy/ massages to your dog aswell.
Finally if you suspect chronic discomfort then non steroidal anti inflammatory drugs NSAIDS, like ibuprofen can help ease joint pain. DO NOT GIVE ONE FROM YOUR CUPBOARD. Your vet may prescribe these to ease your dogs discomfort and must be dosed accordingly to your dogs weight.
