Although these sound like different breeds of horse, these three “breeds” are actually just coat colors, which can occur in a whole lot of horse breeds. They are more common in some breeds than in others, but most often occur in a few specific breeds like the Pinto, the Paint horses and certain Cob types, like the Irish Vanner. The difference between Tobiano vs Overo vs Tovero is the type of coloring of the coat – and this can vary markedly.
What You'll Learn Today
Colored horses have been around for centuries. They arrived in America with the Spanish explorers in the 16th century, and they flourished on the plains, becoming the wild herds that ran free and were used by the Native Americans for carrying loads and hunting.
When the English colonists arrived, they introduced the Thoroughbred to the mix, which brought a little more height and elegance to these colored horses, and later still Quarter Horse was added into the breeding pool. Some of the resulting horses were colored, some were solid coated, and the popularity of the coloreds waxed and waned for a while – some loved them, others hated them.
The American Quarter Horse Association was formed in 1940, and excluded all horses with an excess of white from the registry – this included all Tobiano, Overo and Tovero. Because of the growing popularity of colored horses however, the American Paint Quarter Horse and the American Stock Horse Association were born and now horses are bred for a specific coat color.
The genes that produce this type of coloring are dominant, so for a horse to have a Tobiano, Overo or Tovero coloring, at least one of the parents must also have been colored. The main difference between Tobiano, Overo and Tovero is the type of color. At first glance they may all just look like white horses with splashes of color, or a base color with splashes of white, but look closer and you will see distinct differences between the coats.
Tobiano horses have a coat of a base color with white patches, caused by light skin pigmentation. They generally have white legs from the hock down, white crossing the back between the withers and the dock, and facial markings which are generally not more than a star or a snip or a blaze. The white patches are generally oval or rounded in shape, rather than jagged. Tobiano coloring is caused by a dominant gene, so any Tobiano colored horse must have at least one Tobiano parent.
Overo is a Spanish word meaning “like an egg”, and the term Overo contains three distinct subsections, all of which are caused by different genetic patterns:
The Frame Overo is the most common pattern, and is a solid base color with irregular white patches. The markings are jagged, and rarely cross the back or go down the legs. The tail is usually dark while the face is usually white, and blue eyes are not uncommon.
This type of coloring is occasionally affected by an autosomal genetic disorder called Lethal White Syndrome, which produces all-white foals with blue eyes, which have a non-functioning colon and die within a few days of birth. Not all Frame Overos carry this tragic gene however, and parents can be tested before breeding to make sure they are not carriers.
Sabino coloring tends to include white stockings on all four feet, and white patches on the lower barrel extending to the flanks. The head is generally white, with markings extending beyond the eyes and roaning at the edges of the markings. “Lacy” markings can occur anywhere on the body, particularly the belly.
There has been some confusion around this classification, as it used to be applied to “anything that is not Tobiano”, without acknowledging the subtle differences in coloring. As we understand more about the genetics that cause these coat colors, we can narrow down the classifications and discover more differences between these horses.
Splashed White Overo
Splashed White is the least common of all the patterns. It has been described as a horse that looks like it has been dipped in white paint, as the legs and bottom portion of the body are white, as is the head, while the rest of the body is the base color. Blue eyes are common with this pattern. Recent studies show that Splashed White may be caused by a dominant gene, and interestingly this type of coloring produces more deaf horses than other types.
A Tovero shows the characteristics of both Tobiano and Overo. A Tovero can have Tobiano type rounded markings yet have irregular facial markings, and one or both eyes may be blue.
Many Tovero horses have what is known as a “medicine hat” – dark pigmentation around the ears and forehead, as well as dark patches around the mouth and chest and flank spots which are isolated but may extend up the neck or along the barrel. Some Tovero horses can appear to be a solid coat color, but this is simply because the gene is not very strongly expressed – test them and you will find the gene for Tobiano, Overo or a combination of the two.
Tobiano Vs Overo Vs Tovero
You can find Tobiano, Overo and Tovero horses in just about any breed. These horses can be used for anything; from hard working farm horses to show jumpers and endurance horses; they can excel in the show ring or be used as hacks to ride around country lanes. Because it is the coat color rather than the breed that defines them, they can literally be used for anything.
Tobiano vs Overo vs Tovero – these eye catching colors are caused by difference in genetic make up, and there is still much that is not understood about it. Some patterns may be polygenic, some dominant, some incomplete dominant – research is continuing into why these horses look the way they do. Even if we never fully understand, there is no denying that all these horses are very striking to look at, so if you have your eye on one of these multi-coloured mounts now you know a little more about them!