Unlimited access >

What color testing should I do ... or even bother?

I have a palomino pinto Morgan/qh/paint mare and am considering doing coat color tests on her. Her dam was a palomino (blaze, three fairly high white socks) and the sire was a chestnut tobiano paint. From what I understand, my mare cannot be homozygous for tobiano, as her dam was a solid palomino. She does have quite a few ‘ink spots’ that are often common in homozygous horses, from what I understand. Should I even bother getting tests done?

Palomino by default means ee (homozygous for red), and Crcr (heterozygous for cream)

By parentage, you’re right that she can only be Tt (hetero for Tobiano) unless there’s the rare situation where the dam is such a minimally marked Tobi. What breed is the dam? Paint is the only breed in that mix who can be tobiano, it doesn’t exist in Morgans, and a registered QH wouldn’t have it either.

What “ink spots”? I assume you mean some dark spots on her body? Those are Bend Or spots, and are relatively common on red-based colors

The only thing worth testing would be Agouti (which turns black-based horses into bay-based), and that’s really only if you were planning on breeding and wanted to increase your chances of a certain color. Actually, the other test potentially useful for breeding info would be white patterns - Whites (Dominant White), Splash, and definitely Frame overo unless a breeding would be to a breed who doesn’t carry Frame (and Morgan, QH, and Paint definitely do), or you use a tested n/n stallion

Aside from color testing, unless the QH and Paint sides of things have totally clean 5/6-panel testing, I would get that done, the 6-panel, to find out about HYPP, PSSM1, and MYHM

3 Likes

Ink spots - also called cat tracks - are the dark marks within the white of the tobiano pattern. Some claim they only happen in homozygous horses, but I don’t think the genetic testing backs up that statement.

Ah, referring to Tobiano ink spots, somehow I thought she was referring to Bend Or spots.

Ink spots are irrelevant in the zygosity of Tobiano I couldn’t tell you the % of TT vs Tt horses that have them, but it’s likely pretty similar, as it doesn’t mean anything abou the zygosity.