Coat colour Tobiano / Tobiano spotting (KIT-related) - Horse

What does this test examine?

This DNA test examines the KIT-related chromosome 3 inversion that produces the Tobiano allele, also called TO, in horses. Tobiano is a well-known white-spotting pattern and is also described in Dutch as platenbont.

Tobiano in horses

Tobiano horses usually have sharply bordered white patches on the body that often cross the topline. White legs are common and the skin below white areas is pink. The head is often relatively darker than in some other pinto patterns, although ordinary face markings and other colour genes can modify the overall appearance.

Inheritance and result

The TO allele acts as an autosomal dominant trait. One copy causes the Tobiano pattern and can be passed to about half of the offspring. Two copies also cause Tobiano and mean that the horse passes a TO allele to all offspring.

Practical value of this test

• Confirms whether a horse carries the Tobiano allele, even when other white patterns make the appearance harder to read.
• Helps breeders plan which foals may show Tobiano or will certainly inherit a TO allele.
• Clarifies the difference between Tobiano, Tovero-like combinations and other white-spotting patterns.
• Supports sale, registration and colour planning with a concrete genetic result.