Our second monthly mystery horse is Rahane Nigel, a.k.a Winnie. Winnie is a Welsh B gelding. He is registered as palomino, but has dark points and both dark and light colouring in his mane and tail. Is he buckskin with a silver or heavily frosted mane and tail, or sooty palomino? Winnie’s owner told us that this parents were chestnut and grey, so we can’t figure out Winnie’s colour just from parentage.

To identify Winnie’s colour we tested for red/black, agouti, cream silver and dun. Winnie also has three white socks and a blaze. We tested for W20, sabino 1 and splashed white 1 (SW1) to find the cause of his markings.

 

The agouti and extension (red/black) results for Winnie were A a, e e. This means his base coat colour is chestnut, not bay or black.

His cream result was Cr n (one copy of cream), while his silver and dun results were negative. Together with his chestnut base coat colour, this means that Winnie is a palomino.

Some palominos can have dark marks through their coats or all over their bodies (sometimes even, sometimes patchy). This colouration is called a sooty palomino. In Winnie’s case, only his legs, mane and tail are sooty. This may be because he has one copy of the bay factor (the A part of his A a genotype). This is the same gene that keeps black to the mane, tail and points on bay horses.

We also tested for W20, sabino 1 and SW1 to see if we could find a gene that explains Winnie’s blaze and socks. These tests showed that Winnie carries one copy of W20, and is negative for SW1 and sabino 1. W20 often causes a blaze and socks, although the amount of white it causes varies enormously from breed to breed. W20 can also boost the amount of white caused by other white marking genes.