Dörflein had to sleep on a mattress next to the cub at night because Knut needed care. Dörflein also had to play with, bathe, and feed the cub every day. Knut's food began with a bottle of baby milk mixed with cod liver oil every two hours. At four months old, he could eat milk porridge mixed with cat food and vitamins. Dörflein also appeared with Knut on the twice-daily one-hour shows at the zoo. Because of this, he appeared in lots of videos and photographs with the cub, and became well known in Germany. He also won Berlin's Medal of Merit in honor of his hard work and care for Knut. Dörflein died of a heart attack on 22 September 2008.