What is the overo spotting pattern?
On the one hand, overo can be loosely defined as any white spotting pattern that is not conventional markings, not tobiano and not appaloosa. Refer to the rules of the Paint Horse Association for a more descriptive definition. More than one gene is likely to be involved in the overo phenotype. As the genetic complexity of the overo pattern has become more obvious, the descriptive terms frame overo, sabino and splash white have been more frequently used to attempt to define the variations. The spotting pattern in horses with the LWO gene generally corresponds to the frame overo pattern, with white markings on the head and sides of the body, not necessarily on the legs, the belly or the dorsal midline. Q: I have a frame overo Paint stallion that has sired three lethal white foals. Should I have him tested? A: You have genetic evidence in the form of progeny testing to define his genetic status. He is an NO. You will want to advise mare owners that to avoid producing lethal white foals, t
