Frederic Audeoud-Fazy Jacques-Laurent Agasse (1767-1849)

The picture has something of this: cavalry, mammal, horse, mare, seated, equestrian, two, stallion, equine, farm, pony, racehorse, animal, mane, livestock, motion, chestnut, pasture.
Perhaps it’s a painting of a man standing next to a brown horse with a white dog in the foreground and a brown and white.