Synoquin Cat capsules at a dose of 1 capsule per day (removed from capsule and mashed into small piece of banana). Recommended by exotics referral and own vet.
Can also use things like Arthri-Aid, Cartrophen etc. Many options available.
Glucosamine helps to keep joints mobile but it won't delay the process of arthritis. The best thing for that is NSAID's as the anti-inflammatory action helps limit the joint damage from inflammatory processes and of course it also helps with the pain.