While grooming is not difficult, breeders recommend that it be done daily to maintain the quality of the coat and because of its thickness and the constant shedding, with trimming every 1–2 months. The outer coat is long, straight, and harsh in texture while the undercoat is soft, thick and short. The coat knots and tangles easily, particularly when the undercoat is being shed, which happens twice a year. The life expectancy of a Pomeranian is 12 to 16 years. A well-bred dog on a good diet with appropriate exercise will have few health problems; and, if kept trim and fit, a Pomeranian is a sturdy dog.