An animal watering device is provided that is automatically fillable for providing water to animals, such as horses or other livestock. Animal watering device includes a base, a trough positioned within the base for storing water, and a water filling assembly coupled with the trough to control a water level within the trough. A ring can be positioned about an upper surface of the trough to protect the upper surface of the trough. A disc can be positioned within the trough to cover a portion of water filling assembly positioned within the trough, while allowing water to flow through the disc.