I started my whippet on Cosequin after a partial carpal fusion surgery in 2004. He is just starting to show signs of arthritis now - he'll be 11 in June. I believe it delayed the onset of the arthritis. The vet switched us from Cosequin to Flexadin (same company, slightly different formulation). This year I also started to give him Wobenzym and Zeel daily and they seem to help as well.
Quick question about the Cosamin: do you need a prescription to purchase it at Costco, or is it OTC? I want to start my grey Arlie, who will turn 8 this year, on a joint supplement proactively, and the Cosamin sounds like a possibility.