A calf catching apparatus that attaches to an ATV or similar vehicle and operates along the side of the vehicle. The calf catching apparatus has a pair of doors or gates that open to the front and are operated from ATV. The operator drives along side the cow/calf pair until the calf is inside the pen. The gates are closed and the calf is caught and separated from the cow. The operator can enter into the pen and treat the calf. If the calf needs to be transported, the calf is placed on a transportation platform and a gate is closed to restrain the calf on the platform. The calf catching apparatus can also be transformed to a tow behind version to minimize the width and bring the unit down the road behind a vehicle. There is also a fold-up embodiment that allows for the pen to be folded beside the ATV to reduce the overall width of the ATV and calf catching apparatus for traveling through narrow openings or on roads without unhooking from the ATV. In normal operation, one side of the calf catching apparatus is supported by the ATV and attached to the ATV in a manner that allows the calf catching apparatus to pivot vertically around the center axis of the ATV to allow for proper operation in rough terrain.