Nestled in the mountain Valley of the Sun in the geographical center of San Diego County, White Dragon Ranch specializes in smooth-gaited Missouri Fox Trotters carrying the dominant curly coat gene.
In May 2013 genetic testing found that all 6 adult dominant-curly Missouri fox trotters and the one straight-coated MFT filly at WDR are homozygous (2 copies) of the DMRT3 gene mutation linked to “gaitedness” in horses. WDR’s American Baskir curly gelding is homozygous for the wild-type DMRT3 (not gaited) gene.
See Andersson LS, et al. Mutations in DMRT3 affect locomotion in horses and spinal circuit function in mice. Nature vol. 488, August 2012, pp. 642-646.
Curly horses were first observed in the modern age among wild mustangs in western U.S. states and are still found among wild herds to this day. The dominant curly gene in Missouri Fox Trotters traces back to a gaited curly stallion of unknown ancestry named Curly Jim. Some of his gaited, curly daughters were bred to fox trotting stallions and their offspring were registered in the MFTHBA in the 1950s and 1960s. There are few dominant curly fox trotters alive today and all are at least distantly related. Most are descendants of a single MFT sire, Walker's Prince T.
There is no genetic test for the dominant curly gene. If a horse inherits one copy of the curly gene from either parent and is bred to a straight-haired horse, there is a 50% chance his/her foal will have a curly coat. A horse that inherits 2 copies of the curly gene (one from each parent) will always produce curly-coated foals.
An interesting characteristic of curly horses is the evidence that they are hypoallergenic for many people allergic to straight-haired horses. Many allergy sufferers are able to touch, groom, and ride curly horses.
For more information on these horses, check out these links:
Missouri Fox Trotting Horse Breed Association (MFTHBA)
International Curly Horse Organization (ICHO)