breed of toy dog that originated in China and was introduced to Japan, where it was kept by royalty. The breed became known in the West when Commodore Matthew Perry returned from Japan in 1853 with several dogs that had been presented to him. The Japanese spaniel is a compact, dainty-looking dog with large, dark eyes, a short muzzle, and a heavily plumed tail that curls over its back. It stands about 8 to 11 inches (20 to 28 cm) and weighs about 7 pounds (3 kg). Its full, straight, silky coat is black and white or reddish brown and white. The breed is valued as an alert, affectionate pet.