[JBandRio]

Originally Posted by Kitari

what causes it or is genetically linked to it?

It is genetically linked to the Frame Overo gene.

Tobianos do not have it, neither to Sabinos or Splash Overos. Only the Frame Overo.

[JohnnyBob'sMyBoy]

i read somewhere when i was doing my research on it when we decided we wanted to breed her that some horses can not have it but carry it [like equine infectious anema (sp?)]....is this true???

[Shannon]

Originally Posted by lovebandit

i read somewhere when i was doing my research on it when we decided we wanted to breed her that some horses can not have it but carry it [like equine infectious anema (sp?)]....is this true???

Right, LWS only affects the horse when it's homozygous, or has two copies. Every frame overo horse has one copy of LWS, so it's not very safe to breed two frame overo horses together because you have a 25% chance of the baby getting a copy from both parents.

Hope that helps!

[JohnnyBob'sMyBoy]

ok thanks!

[JBandRio]

Originally Posted by shannond

Right, LWS only affects the horse when it's homozygous, or has two copies. Every frame overo horse has one copy of LWS, so it's not very safe to breed two frame overo horses together because you have a 25% chance of the baby getting a copy from both parents.

What shannon said, AND, because Overo is something that can be present, but either not be expressed, or be expressed but also visibly covered up by another pattern or gray, if your breeding horse has any chance of having any pinto in the background - Paint, TB, etc - then it's worth the peace of mind to do the cheap test.

[Solsalia]

Originally Posted by LotsOfSavvy

This stallion is homozygous black and heterozygous agouti (based on the fact that his site says he produces smoky blacks) he also is OLWS negative. He does carry the overo gene which would increase your chances of getting overo.

I would recommend getting your mare's agouti status tested. Thats what I did for my mare...turns out she is Homozygous Agouti. She will never have a black foal if I breed her to my Homozygous Black Stallion. But She can have buckskin, bay, etc. For me, it was worth the $25.00 I paid to have her agouti tested.

If it turns out your mare is AA like mine (homozygous agouti)...you just need to find a stallion that is homozygous black and homozygous creme...wouldn't matter what his agouti status is...If she is Aa or aa then you can figure you need a stallion that is AA to guarantee buckskin or a stallion that is Aa for a 75% chance buckskin. Providing, of course, the stallion has passed all other requirements you may have for him including conformation, temperment, etc.

I love that stud! He's registered as a solid though and so i'm not sure why they say he has an overo gene. The only registered overo's he's had on the apha registry are from overo mares, the rest were solids babies.

[Kitari]

so splash overo's dont have it, i did not know there were differences in overo, a frame overo is?

[JBandRio]

Overo covers Frame, Splash, and Sabino.

Sabino is responsible for white stocks and blazes. When it goes wild, it can cause very colorful horses with lots of "roaning", and even an all-white horse.

Frame is when the color is restricted to the outer edges of the horse - the "frame" of the horse. This could be a thick frame, or a thin one. It can mean just a few spots on the sides of the horse, or it can mean just a thin outline of color around the edges when looking from the side.

Splash looks like the horse was dipped in white paint, or had color poured on from the top. If there are only white legs involved, the difference between thata caused by Sabino, and by Splash, is that typically Sabino will have jagged edges, with the marking often ending in an upside down V. Splash will tend to have a more abrubt ending, more horizontal, not jagged. Splashes also tend to have blue eyes, whereas even if a Sabino had wide white markings on his face, usually won't have blue eyes.

Because all 3 of these are separate genes, they can all exist at the same time, AND can exist in the presence of Tobiano as well.

[haunani]

Originally Posted by solsalia

I love that stud! He's registered as a solid though and so i'm not sure why they say he has an overo gene. The only registered overo's he's had on the apha registry are from overo mares, the rest were solids babies.

It's possible he was registered as a foal before they knew he carried the overo gene. Or, they just state that to put the minds of potential clients at ease.

[Blistering Winds]

You register the horse to the pattern they express. So technically, he isn't colored "OVERO", well, he's a minimally expressed overo...but solid just the same.

Many solid AQHA horses carry the overo gene. And until you test or know the parents were definite overos....it is hard to make a call on the solids.

The term Overo, Tobiano, Tovero is how the horse looks Phenotypically. Not just genetically. While there are several "overo" looking horses that have no overo gene, they are Sabinos. But it is hard in some cases to determine what threw the color pattern without genetic testing and looking at the parentage of the horse.