Some of you may have read, or heard about, an article or two which appeared in a spotted horse breed publication about these horses. There were some disturbing things presented in there, and although written very well, the data had not been researched. Too many inaccurate conclusions were drawn which were not based on fact, or scientific information.

Firstly, the "tovero gene" theory must be dispelled. There is no such thing. Tovero is simply a cross between the Tobiano and the Overo where both patterns appear on the body of the horse. Tovero is no more a gene, than is Morab a breed. Both are just crosses. The tovero horse can pass on to its foal either the tobiano gene, the overo, both, or neither. And in most cases, it is the luck of the draw.

Tobianos who are homozygous--100%-Color sires or dams--are the exception. No matter what the mate does for the foal, this horse will always color every foal. Tobiano is the only pattern that can be homozygous. Overos do not breed true. So if a homozygous (double-gened) tobiano was bred to a heterozygous (single-gened) tobiano, the foal would be colored because of the double-gened horse. However, the single-gened parent may also pass on pattern to the foal. If this horse did that, then the foal, too, would be homozygous for pattern and would color all of its foals one day.

Each horse has two genes capable of carrying tobiano pattern, and these two genes either do, or they don't. If a tobiano parents a solid foal, then pattern is lost to that foal. Tobiano is a dominant gene. Now, if a horse has two tobiano parents and both happened to pass pattern to the baby, then the foal's two genes capable of carrying pattern obviously would. This is called a double-gened, or homozygous horse. If a foal receives only one copy of tobiano from its parents, then it is a colored foal, but is single-gened, or heterozygous.

Two homozygous horses create homozygous foals....there's no other way around it. A homozygous and a heterozygous cross will result in 50% homozygous foals, and 50% heterozygous. This, of course, is the average. You've a 50/50 chance at each mating, but Mother Nature does what she will and may or may not bless you with the average. You can get any number of one or the other...and no one can predict what will actually happen in this type of cross. Two heterozygous horses will have a 25% chance of creating a homozygous foal, 50% chance of a single-gened foal, and a 25% chance of a solid foal. Percentages in any cross are the same chances in every mating. Some people think you get one foal out of the way, and in the next three breedings, you'll get the other possibilities. This is not the case, and you get what you will at each crossing.

Now, the Overo is a different story. It's been labeled as sort of a wild gene. It does what it wants, to a point. It is not a dominant gene in the same sense as is the tobiano. I like to refer to it as a dominant-recessive, for lack of better terminology. What this means is that it is recessive because it doesn't always put pattern on the body even when the gene is passed on. However, unlike most recessives, it only takes one copy of the gene to create the trait on a foal when it does decide to color. This is surely evidenced in many breeding sheds, when crosses between Arabians and overos take place and overo foals result.

In one particular article that comes to mind, the writer described how these 'Tovero' horses, and he was talking about stallions, were siring 80% color; or passing on color more consistently if they had more white on their bodies; or other such misleading things.

One BIG mistake made is that all that was looked at was the foal record. Of course, a stallion may have 80% of his foals registered as being colored, but the question is...."Who did the coloring?" If a colored stallion is bred to a colored mare, then that colored foal cannot be used in the creation of the color record on either horse if the goal is to prove who did the coloring on the foals. If you want to prove a color-passing record on any horse, it cannot be bred to colored mates. All doubt has to be removed that the other mate might have colored the foal. An Arab stud could be bred to 100 Paint mares and have an 80% colored foal record, but I'll guarantee you that he didn't do the coloring. He has no tobiano or overo genes to pass on! The same is true in reverse for colored mares as well....they cannot be bred to colored stallions and have an accurate color record.

Oftentimes, when tobiano and overo patterns both go to a foal, the baby ends up with excessive white. When the two patterns nick, there is little that can be done about it. However, just because a horse has excessive white, doesn't mean he/she will have mostly white babies. The genes do not have a blue print to follow to suit our needs for the standards we think are "right". Like I said earlier...Mother Nature does what she will, and the spots land where they may and in the pattern or places they so choose. Just because a spot may not be in the "right place", or of the "right size", doesn't meant the horse isn't patterned. Genetically it can can do just as much coloring as one who is loudly patterned. On the other hand, for those who do pass on both patterns to their foals, of course the possibility exists wherein the foal could get extra white....because both patterns are colors mixed with white and a double dose of pattern obviously ups the chances of more white. However, the mixture of the two patterns that results in this excessive white has no bearing upon how much potency for color the horse can physically have. The bottom line is that a single-gened tovero has a 50/50 chance of passing on the tobiano pattern, and likewise, similar chances for the overo pattern. But bred to colored mates, unless you absolutely have your genetics program nailed down (like those of us who breed for homozygous and related horses), one would rarely know who colored what in a two-colored-parent cross.

Also demonstrated in a particular article were a few stallions who were homozygous for tobiano. These horses should never be considered against single-gened toveros because every foal they parent will be colored. This is an unfair advantage for comparison's sake, and they are in a whole 'nother class of their own!

Trying to explain all of this to many people might prove frustrating. They only see a big blob of white when looking at some tovero stallions to possibly breed their mares to. But with knowledge and understanding, we can hopefully turn peoples' thinking around and tell them what their real chances of pattern are, and discuss with some authority the phenotypic expression of these patterns.

In January of 1996 I authored Understanding & Breeding for the Homozygous Tobiano. It is the only comprehensive work of its kind, and I spent painstaking hours on its accuracy. The key features of this work are that everything is explained, and it's done in layman's terms. No medical mumbo-jumbo for those of us who can't understand that stuff without a medical dictionary in our hands. There was little help out there when I first started learning about it, and I spent considerable money and time to learn about it all the hard way. Doing this work gave me great satisfaction in knowing that I've saved many people the trials and tribulations that I went through myself. Having done this work, I HAVE to be accurate, and strive to clear up misconceptions whenever I can. Truth and knowledge are power, and having both of these will save many people lots of money....with these two assets on their side, they will not be easily fooled into "too good to be true" deals that go awry after their checks clear. Buying something they 'thought' they were getting.

I, personally, have had horses for nearly 20 years. I've formal education, too, but most of my training is from "in the field", sometimes the best place to be. I got a great start at Black Hawk College in Kewanee, Il., and once my fire was lit there, I continued to study long after leaving, to get where I am today. I'm not rich and famous by any means, but I am secure in that I know what I do is correct, and I'm helping people learn about these wonderful "painted" horses, and I enjoy immensely my colored foals I get each spring. I've a small herd of 18 head, and several can be seen on my website at www.brodnet.com/hr-all-tobianos.

Thank You for taking of your time to read this article, and I can only hope it has shed some light on the subject of pattern for you. Feel free to contact me with any questions you may have! I can be reached at: E-mail: TT-Paints@ckhnet.com or tel: (608) 329-PAINTS. (evenings)

May You Always Own A Good Horse.....

Carolyn Schultz
HARLEQUIN RANCH
Homozygous Stock
Monroe, WI
E-mail: TT-Paints@ckhnet.com

This article was reprinted with the authors, Carolyn Schultz permission.