Horses Watering Henry Meynell Rheam (1859-1920)

The picture has something of this: mammal, livestock, cavalry, animal, hayfield, grass, cattle, seated, farm, field, herd, grassland, rural, pasture, cow, two, agriculture, outdoors, countryside, cowman.
Perhaps it’s a painting of a group of men on horses next to a stream with a dog on the other side of the painting.