Adult cats are lactose intolerant. Like some humans, adult cats don’t have enough the lactase enzyme to digest lactose from milk, causing them to vomit, have diarrhea, or get gassy. Cats only have enough of that enzyme when they’re born and during the early years of their lives.
100 Mind-Blowing Intolerant Facts
Adult cats are lactose intolerant. As ironic as it sounds, feeding your grown cat milk can irritate their bowels.
Despite popular belief, many cats are actually lactose intolerant.