Paint

The American Paint Horse is a Quarter Horse with white markings and a bloodline requirement. Registration demands both stock-horse breeding, from the Paint, Quarter Horse or Thoroughbred registries, and a qualifying coat pattern.

The patterns have names that matter. Tobiano is white crossing the topline with a mostly solid head; overo, which covers several distinct genetics, generally does not cross the back and carries a white face. Tovero is both.

They have the Quarter Horse build and disposition and are used for the same work: ranch, rodeo, western performance and general riding.

The trade is one specific and fatal gene. The frame overo pattern is caused by a mutation that, when a foal inherits it from both parents, produces lethal white overo syndrome: a white foal that dies within days. It is testable, and breeding two frame carriers together without testing is inexcusable.