[qraven]

Originally Posted by Pinehaven

Lethal white is cause by breeding 2 overo pinto horses together. You can breed other spotting patterns together like sabino to overo, tobiano to overo or splash white to overo without the problem of producing lethal white ... it's the overo to overo crosses that can produce lethal whites (25% chance). Unfortunately, you can have a horse who looks to be solid colored but are in fact minimally marked overos.

There is a test to determine if a horse carries the Lethal White gene, so many horse breeders who breed pintos will have their horses tested for the LWO (Lethal White Overo) gene or they will avoid breeding overo to overo all together.

thank you Sue