Our monthly mystery horse is Apoco-D Paris, a miniature horse mare. Paris looks brown or black all year round, but is registered as chestnut. Her parents were black and palomino, and she has had several foals of various colours (silver taffy, black, chestnut and palomino).

To identify Paris’ colour we tested for red/black, agouti, cream and silver. She also has a blaze, so we tested for W20, sabino 1, frame overo and splashed white 1 (SW1) to see if we could identify that as well.

The agouti and extension (red/black) results for Winnie were A a, e e. She was negative for cream and negative for silver. So Paris is actually chestnut! Her silver (taffy) foal must have inherited silver from the sire.

Chestnut horses come in a variety of shades. While most are orange or coppery, some are darker to the point of appearing almost black. This beautiful dark liver chestnut colour is rare and desirable, but unfortunately there is no test available at the moment that lets us predict which chestnuts will be liver chestnut.

We also tested for W20, sabino 1, frame overo and SW1 to see if we could find a gene that explains Paris’ blaze. Frustratingly all these while marking tests were negative. There are still plenty of untestable white marking genes out there.