The Acti-Flex Liquid Horse Joint Supplement can help support your horse's back, knees, fetlock and other joints. Containing hyaluronic acid, Acti-Flex is made to support a horse's natural abilities in order to promote better mobility and joint lubrication. Acti-Flex can also help repair stress-related joint damage. This equine joint supplement is sold in a liquid form and is easy to administer thanks to its delicious pina colada flavor that horses love.