Miniature Horse Genetics
When you want to breed seriously, you have to know how genetics works and what are the consequence of some crossings. Almost every horse color gene exist in the American Miniature Horse, of course this variety allows us to do what we like, but we also need to know genetic disease and anomaly.
Almost all of our horse are tested on their color gene to know what they hold. We will only talk about gene which concerns us.
Silver : It's a dominant gene which is quite common in AMHA horses. It changes black pigment on mane and tail in white. Moreover, the gene can affect the eye and create ocular anomaly (MCOA) more or less severe if it's heterozygous or homozygous. Some anomaly can be identify by a ophthalmologist but it's safer to not cross two silver together.
In general, AMHA are rustic, but they are also concerned by few genetics diseases, which we need to know and act accordingly.
ACAN D1 à D4 : It's the 4 principal mutation of Dwarfism which exist in American Miniature Horses. Every type has different forms and consequences. Dwarf horses have hydrocephalus, twisted legs, deviated spine, prognathism, and a very tiny small size. Internal organs are in a bad shape too, their life expectancy are a lot shorter. This disease is degenerative and touch some other species like Frison, Shetland Pony or Welsh Pony. Two carriers together have 25% of risk to produce a dwarf foal. That's the reason why we decided to have 100% of our horses free of all 4 ACAN mutations.
Skeletal Atavism : It's another form of Dwarfism which is characterized by an imbalance of growth. Rarer than the ACAN, it is also important to test it. About 12% of the worldwide livestock is touched by this form. Their is two mutations which can be tested : Del1 and Del2.
Our two stallion, Vivo & Haston are free N/N, as well as Vendetta. The other mares will be tested in 2020 and their results will be available on their page.
To learn more, don't hesitate to read this article co-written by veterinarians Mme SACHDE and M. Leclerc for the AMHA France.