Kentucky Mountain Saddle Horse News

Sept/Oct 2006

Great Gaits

by: Barbara Weatherwax


Spotted Mountain Horses

The “Sports Models” of the Mountain Horse Family


Part 2  (Part 1, July/August issue)


There are several terms associated with the Spotted Mountain Horse which are useful to know. TOVERO is a cross between tobiano and overo. PIEBALD is always black and white – in tobiano, overo and Sabino. SKEWBALD is any combination of color other than black and white. Both palomino and white, and bay and white would be considered skewbald. CALICO is usually found in overo and Sabino horses that are roan and spotty white. REBECANO (also known as Squaw Tail) describes white at the base of an otherwise colored tail. It is most common in overo coloring. DISTAL or ERMINE spots are roanish spotted edging around a dark colored spot. Skin under these edgings will be dark. INK SPOTS are dark skin spots with white hair covering them. They are usually found in large white spots and sometimes found on the legs of high-stockinged horses. These spots are sometimes referred to as “spots on spots.” TODAINIAN is a color pattern found in tobiano horses. It is white over the back and the hind quarters.

WALL EYES, CHINA EYES, and GLASS EYES are all terms describing blue eyes, which are a frequent characteristic in spotted horses. The blue pattern does not impair vision.

Genetic study of the multicolored horse has made tremendous advances in recent years. There are definite “recipes” determining “get.”

The sire contributes 50% or one gene to the foal and the dam contributes the other 50% or one gene.

The tobiano gene is dominant. If the sire has a tobiano gene T and a non-tobiano gene t, and the dam has the same combination, there are only four possible combinations.

1) sire T dam T

2) sire T dam t

3)  sire T dam t 

4) sire t dam t

Since T is dominant, the get from 1, 2, and 3 would be tobiano. The product of 4 would not be tobiano. So the chances of getting tobiano from such parents would be 3 out of  4.

The overo gene is recessive. The horse must have two overo genes before it will display the overo pattern.  If the sire has a non-overo gene O and an overo gene o, and the dam has two overo genes oo, the four possibilities would be

1) sire O dam o 

2) sire O dam o  

3) sire o dam o and

4) sire o dam o

There would be a 50-50 chance of producing an overo foal: 3) and 4) would be overo, and 1) and 2) would not.  Unfortunately, there is no blood test to identify the overo gene in advance. Trial and error has validated the formula.

HETEROZYGOUS and HOMOZYGOUS are two other terms that are part of the Spotted experience.  Heterozygous is designated by the symbol Tt and it means the tobiano horse will produce tobiano offspring 50% of the time. When the tobiano gene T is passed to offspring, the resulting foal will be tobiano. When the solid color gene t is passed to offspring, the resulting foal will be solid color. Most tobiano horses are heterozygous.

Homozygous is designated by the symbol TT and it means the tobiano horse will produce tobiano offspring 100% of the time.  The homozygous horse has no other gene to give the offspring. In breeding practice, if a horse produces or sires a solid-colored foal, the horse is heterozygous.

The homozygous horse is very valuable in Spotted Mountain Horse breeding programs. Homozygous foals are produced by breeding a tobiano to tobiano. Of  this mating, 25% of foals will be solid, 50% will be heterozygous tobiano and 25% will be homozygous tobiano.

So there’s a lot to be proud of in our Spotted Mountain Horses.  They truly complete the family of KMSHA.


Please contact me on my email:  with your specific questions or thoughts about the Mountain Horses. And Happy Gaiting!