Why do cats purr?

A cat purrs from contentment and pleasure. Purring is a unique vocal feature in the domestic cat. However, other species in the Felidae family also purr: Bobcat, Cheetah, Eurasian Lynx, Puma, and Wild Cat (Complete list in Peters, 2002). Although some big cats like lions exhibit a purr-like sound, studies show that the Patherinae subfamily: Lion, Leopard, Jaguar, Tiger, Snow Leopard, and Clouded Leopard do not exhibit true purring (Peters, 2002).”