There is a product called Glycoflex that is available from your veterinarian. If I remember correctly, it's not exactly the same as chondroitin and glucosamine, but similar. It's made out of the green mussel that the article talks about.
I'm using chondroitin and glucosamine for my german shepard (no hip sockets) and he's done unbelievably well on it. You can't tell there's anything wrong with his hips at all.
I did talk to one vet who saw wonderful results in some of his patients from the glucosamin/chondroitin, and then tried it on himself with no results at all. I take it, and I move a lot easier.
Funny you would mention Glycoflex. We just switched vets to Banfield animal hospital, a franchise that co-locates with Petsmart. The vet did Duke's preliminary physical last week and suggested the glycoflex. She came out into the store and examined the dog food we're feeding Duke (nutro max senior large breed) and the dog biscuits (they have shark cartiledge) and she indicated these products provided all the stuff the glycoflex provided. I'll ask her Friday about the green muscles. Duke's gettin his comprehensive physical then.