Tobiano or Overo?

A. Tobiano (which is pronounced "TOE-bee-AH-no") and overo (which is pronounced "oh-VAYR-oh") are two patterns of large, irregular spots in horses. Although both these patterns are non-symmetrical, they are separate and distinct with very different genetic characteristics.

The well-defined spots of the tobiano cover the body randomly but white ordinarily crosses the topline at some point between the ears and the tail. The head is usually covered but often has teh white markings associated with those of non-spotted horses (such as a star, strip, blaze and/or snip, etc.). All four legs are generally white. Thee Pintabian horse would be a perfect example of this popular pattern.

Because of the dominant genetic make-up of this spotting pattern, at least one parent must be a tobiano to produce a tobiano. In other words, two solid (non-spotted) horses cannot produce this pattern.'

Overo, on the other hand, occasionally "pops up out of the blue" in two solid colored horses because of its genetic characteristics. (Breeders call these horses "cropouts" or "throwbacks.") Some horse breeds, which were always "supposed" to be solids, have come to realize this fact.

The white areas of the overo are usually more ragged than the tobiano and do not cross the topline except on horses which carry a great deal of white. The head is marked extensively with white markings called "bald," "apron," or "bonnet" face and it is not uncommon for the eyes to be blue. Overos often have one or more white legs but not usually four.

I will try not to confound the issue, but some horses carry the characteristics of both of these particular spotting patterns. These horses are called tovero (TOE-vayrh-oh) and carry the genetic make-up of both the tobiano and overo spotting patterns.

The topic of genetics should be of considerable importance to the breeder but, unfortunately, many horsemen consider the subject confusing and do not undestand the basics. My advice would be: "don't put the horse before the cart." Know the difference between the patterns, decide which you prefer, and then proceed from there. The purchase of a good book on horse genetics would be a good start and probably your best bet. Many of the "theories" proposed by horsemen (who may be very knowledgable and "experts" in other areas) are simply not accurate.

In addition, please remember that you cannot judge a horse by the color and/or markings of its coat. What you plan to do with the horses you raise, whether it be cutting, endurance, etc., should help you decide what horses you breed. Other qualities, such as disposition and conformation, are also very important.

Reprinted from a Pintabian handout, distributed with the following word search puzzle.