Discussed in the Reddit thread.
Its a Cremello; A coloration rather than a pigment disorder. Albinos would have pink eyes, whereas Cremellos have pale blue eyes...More at the thread. You learn something every day.
A true "white" horse would already be dead as well - the genes associated for a pure white horse contain fatal flaws, known as Lethal White Syndrome, that cause white foals to either be born dead or die within the first day - usually much less time than that...
LWS can also be carried way back in the lineage of the horses, not strictly limited to the Frame Overo cross (they're just known carriers). As thirdpeppermint said, conscious breeders should test for the gene to make sure they're not accidentally breeding it into their lines. Also, the foals aren't really missing a large section of digestion tract. They do commonly have impaired colon development (so the colon may be severely narrowed or even closed off in places). The mark of this disease is the missing myenteric plexus from the ileum caudally. The myenteric plexus is part of the enteric nervous system in the GI responsible for peristalsis, meaning there's no movement of ingesta through the GI tract, resulting in colic-y clinical signs and eventual death
And a hat tip to Dr. Mieke for offering a link to genetic information at the Cremello and Perlino Education Association.
The photo was taken at the 2012 Calgary Stampede by Stu Winston. Via Soul Dipper, with a hat tip to Kelly Durette at Deformutilation.
I saw that thread. :-) As the name implies, a cremello is a pale cream horse. I believe it's the palomino gene combined with one that washes out the color significantly. There's also a coloring called 'perlino', but I don't know the genetics or what distinguishes it from a cremello. They're often desirable for breeding because of the very high odds that they will produce a paint, palomino, or other flashy colors.
ReplyDeleteLWS is terrible. There's nothing wrong with deliberately breeding for flashy colors, as long as conformation, working ability, and health are given consideration as well. Unfortunately there's a subculture of horse people who think that color=value, even if the horse's legs point in four different directions and it doesn't have any manners, and those are the people who end up breeding LWS foals. The test isn't even that expensive - less than $100 I believe.
"As thirdpeppermint said, conscious breeders should test for the gene..." What do the unconscious breeders do?
ReplyDeleteba da boom.
I posted that on my blog awhile back and you can find the photo credit here: http://souldipper.wordpress.com/2012/07/12/occupy-blogosphere-thursday-july-12-2012/
ReplyDeleteHope that helps
You bet that helps. I've added a credit and a via to the post. Tx, Kelly.
DeleteHorses come in two base colors: red (chestnut) and black, which are modified by other color genes. The cream dilution gene is a "stacking" gene, meaning its effect is compounded. A chestnut horse with one cream gene is a palomino. With two cream genes it becomes a cremello.
ReplyDeleteTo answer the question above about perlino:
Black + agouti (a gene that restricts black to the legs/mane/tail)= bay. Bay + 1 cream = buckskin. Buckskin + a second cream = perlino.
The third "double dilute" color is smoky cream, which is a similar color to cremello and perlino. It is a non-agouti black with two cream genes.
Forgot to add...albinism does not exist in horses. All "albino" horses are misnamed - they are double dilutes, pale gray, or the maximum expression of a pinto pattern (or lethal white). :)
DeleteLovely post!! Yes, it's about colour genetics in horses, which is fascinating.
ReplyDeleteA bay base (brown body and black mane and tail) plus one dilution gene will give a buckskin foal. Two dilution genes on that base will give a perlino.
A chestnut base plus one dilution gene will give a palomino foal, two dilution genes in a chestnut base will give a cremello foal.
I have a perlino mare (2 dilution genes). I crossed her with a bay stallion (no dilution genes) and got a buckskin foal (one dilution gene on a bay base). See (before) http://moretons-myth.blogspot.com.au/2010/05/novas-back.html and (after) http://moretons-myth.blogspot.com.au/2010/09/month-old.html
If I cross Nova with a chestnut stallion, I'd get a palomino foal, for sure.
It's a bit difficult to explain in text ... I could draw the genetics diagram on a piece of paper ... Suffice to say, the mare and foal are lovely and loved :-)
Anyway, no such thing as a bad colour on a good horse :-)
Thanks,Dr. Mieke. I've inserted your suggested link to the CPEA as an addendum.
DeleteWhat a great photo. I'm almost more interested in the story of the picture.
ReplyDeleteMy great grandmother maintained that if you saw a white horse you got a wish. No wonder none of my wishes have ever come true...:)
ReplyDeleteI discovered a golden horse breed the other day, the Akhal Teke found in Turkmenisan, they have coats with a metallic sheen.. http://en.wikipedia.org/wiki/Akhal-Teke
ReplyDeleteAmerican Creme Draft is a draft horse breed, the only draft breed developed in the United States, not imported from Europe, that is still in existence. All are Cremellos with blue eyes.
ReplyDelete