LubriSyn HA Hyaluronic Acid Horse & Pet Joint Supplement helps cushion aching joints with an all-natural oral supplement. It restores fluidity of movement with hyaluronan, a substance that is part of synovial fluid that lubricates the joints. This fluid breaks down as animals age, and joints become sore and stiff as a result. LubriSyn HA is a great alternative to painful, stressful injections. It’s easily absorbed by the body to provide relief for cats, dogs and horses of any age, breed or lifestyle.