Hairballs can be prevented by frequent grooming and the routine taking of VetIQ® Defurr-UM as directed. When cats, kittens & rabbits lick their fur, that fur may be ingested, which then accumulates in their stomach and forms what is known as a hairball. Defurr-UM helps to assist passage of swallowed fur through the gut to avoid the formation of hairballs, it does this by coating the swallowed hair and stool and allowing it to pass through the digestive system. Defurr-UM also contains vitamin E.