The word “pied” means sections of hair of different colours, while “pinto” derives from a Spanish-American word that means “spotted or mottled”. This type of colouring is due to a lack of pigmentation in the skin.
Piebald and pinto horses have large areas of white hair, with pink skin underneath. The genetics aren’t predictable. Two solid-coloured horses can produce a foal with typical piebald or pinto markings.
This anomaly has resulted in a separate registry for Quarter Horses with excessive white markings. At one stage, any Quarter Horse foal that showed a “bald head”, stockings above its knees or a white flash on the stomach couldn’t be registered.
As a result, concerned breeders started the American Paint Horse Association. It was noticed that crossing two Paint Horses could result in a solid-coloured foal, so the association also registers horses from paint-coloured parents, even though they may have very little white.
By contrast, the Irish Piebald and Skewbald Association won’t register a horse without large patches of white on its body. A skewbald is a horse with a base colour other than black, such as chestnut, palomino or bay, with white patches. One explanation for this is that the gene for white patches is the same gene that causes a blaze and white feet in a horse that would be considered solid coloured. Thus it’s actually carrying the “piebald” gene.
Types
In South Africa, the Paint and Pinto Association accepts all horses of colour. Registered Paint Horses with pure Quarter Horse bloodlines are judged alongside pintos of any breed. There are some spectacular pintos in South Africa, from American Saddlers to warmbloods, and they make excellent show horses.
In the USA, the pinto registry doesn’t accept draft horses or ponies, and they have different categories. The Saddle Horse type includes Tennessee Walking Horses and American Saddlers, hunter types are Thoroughbreds and warmbloods, the stockhorse type has Quarter Horse breeding, while the pleasure type includes Arabian, Welsh Cob and Morgan horses.
In Ireland and the UK, the main breeds showing piebald and skewbald markings are the Cobs and Draught Horses, so these can be registered. Both breeds are crossed with Thoroughbreds to produce heavyweight jumping horses. The movie National Velvet was based on the prejudice against such coloured horses entering steeplechasing, the Grand National being the most prestigious of these.
Markings
The shape of the white markings is genetically determined. The types of markings are known as tobiano, overo, splashed white and sabino. Tobiano is the most common, with large rounded patches, and usually a large, dark patch over the back and body and a mainly dark head with white or coloured legs.
Overo and sabino horses have a jagged edge to their spots and the splashed gene shows itself as a bald face, four long white stockings and a splash of white on the abdomen.
Contact Dr Mac at [email protected]. Please state “Horses” in the subject line of your email. •FW
