Domestic Longhairs are not a breed, they are a “type” of cat that is mixed with many breeds including Persian, American Shorthair, Maine Coon Cat, and Oriental Shorthair. Longhair cats vary in size depending on the individual characteristics of their breed. They typically weigh between 8-15 pounds with males being larger than females. The average lifespan is around 15 years or more. This breed can grow to be up to 30 inches long from its head to the tip of its tail.