Antique oil painting portrait study of 3 dogs

Antique oil painting portrait study of 3 dogs. English School, circa 1900. Unsigned, artist unknown. Oil on board. Gilt gesso frame. Depicts a couple of puppies with tortoise. Size of frame: 19 x 10.75 inches; Size of portrait: 14 x 6 inches; Size of front portrait aperture: 13.25 x 5.25 inches. Weight: 1.7 kg (allow up to 5 kg volumetric weight once packed). Reasonable condition for its age.