A foal that is born with the lethal white syndrome is born all or nearly white. The foal may act normal in the first couple of hours (i.e., it'll nurse...) but the gene causes a dysfunctional colon, so the foal cannot defecate. Most foals born with this either die on their own or are euthanized within the first 24 hours of life. There is no cure or treatment.

Where there can be a homozygous Tobiano Paint (they guarantee colored babies), the Lethal White Syndrome of Overos is believed to be the homozygosity of the overo gene. If you see an advertisement for a "Living Lethal" do not believe it. That horse is simply all white. There are some sub patterns in the overo pattern that have extremes that produce pure white Piants. There is no such thing as a "Living Lethal", they are simply white breeding stock Paints.

The sabino pattern in the overo gene causes a very loud white pattern on the horse. The extremes are minimal white, where the white is simple speckls across the body, or on part of the body, and don't qualify the horse as a Paint; and an all white horse. There is one example of this extreme living in (I think) Washington state. This stallion is pure white, and it's only because he's at the extreme end of the sabino sub-pattern.

Overo is described as a Paint pattern where the color - or white - does not cross the topline - or back. The white spots are also blotchy, and look like someone took a perfectly good solid horse and splashed white paint across the body.

{mos_sb_discuss:8}