My old vet worked at the racetrack. I owned an old appy mare at the time and she had pretty bad arthritis in her back legs. He had me give her 10,000 mg of MSM a day, and run cold water on her legs for 20 minutes before I rode her, and for 20 minutes when I was done. It did miracles for her. There is a product called Aniflex that works very well on my senior horses and doesn’t break the bank. I wish SmartPak would carry it.