Tobiano vs Overo - Distinguishing the Difference?

Discussion in 'Horse Breeding' started by raisethebar, Jan 20, 2012.

  1. raisethebar

    raisethebar Senior Member+

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    Title says it all.. I'm considering myself relatively well versed with colour now.. but i'm struggling to determine the difference between Overo and Tobaino.. that are the 'give-aways'?
     






  2. Arem

    Arem Senior Member+

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    I'm a little better at showing rather than describing so I'll do a combination of both.:p

    Tobianos typically have four white feet, white that crosses the back somewhere between the wither and the dock. The white often seems to "move" more virtically, and the pattern can also sometimes give circular edges to the white. Tobiano does not cause face white, and, when another gene puts face white on the horse, the tobiano sometimes tries to "erase" it or push it off of the face. Homozygous Tobianos often have markings known as "Cat Tracks," but the appearence of them does not garuntee that the horse is homozygous Tobiano.

    Examples:

    This is one of my favourite examples of the circular edges that Tobiano can cause.
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    The smaller spots inside the white of these horses are the markings known as "Cat Tracks"
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    Sorry if that's a little overboard. Tobiano just has so many neat little variations:eek:

    Now for Overo!

    Overo is the "catch all" term used for horses with pinto white not caused for Tobiano. The Overo Patterns are Splash, Sabino, Domaint White, and Frame.

    Frame Overo is often simply refered to as "Overo." White from Frame tends to move more "horizontally" than Tobiano, and Overo white does not typically cross the topline. Frame, by itself, does not seem to cause leg white below the knees, but it does seem to cause face white. A horse with frame can be soldi or nearly complely colis.
    Frame is also responsible for Leathal White Overo (LWO). Foals who are homozygous for Frame are born with incomplete digestive tracks and die or are euthanized shortly after birth. Heterozygous horses are completely normal.

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    Sabino...
    Is sort of a grey area:p Sabino is caused by many genes, one of which is testable. The testible variation is SB1 and is found most often in Tennessee Walkers. Sabino causes white with jagged edges, roaning, and seems to push white away from the eyes.

    Splash!
    3 variations are now testable. Splash is characterized by bottom heavy blazes, white that "falls off" one side of the face, smooth edges, and horses who look like they been dipped in a vat of white paint. Splash can caus deafness, but not all Splash White horses are deaf.

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  3. HobbitandHawaii

    HobbitandHawaii Full Member

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    For me, what helps me remeber is a simple little trick I learned somewhere.

    A tobiano typically looks like a grey/white horse with colored "paint" spalshed on it.
    An overo typically looks like a solid colored horse wth white "paint" splashed on it.
     
  4. Arem

    Arem Senior Member+

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    I must be tired, I forgot Dominant White:eek2:

    I can go back and add if you like. Unless I gave you over-kill on info already:rofl:
     
  5. JBandRio

    JBandRio Senior Member+

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    This doesn't really make sense though. Each of the Frame (it's NOT just Overo, that's the encompassing term for not-Tobiano, including Frame, Splash, Sabino, and, technically, Dominant White) and Tobiano patterns can present with a little or a lot of white.
     
  6. coloredcowhorse

    coloredcowhorse Senior Member+

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    Tobiano.....by itself does not put white face markings on a horse. The white tends to be in vertical splotches (from withers to shoulder for instance). The typical tobi markings are colored head, chest shield, flank patches and often a tail that is white at the top and colored lower down. The edges of markings are usually rounded and fairly smooth. Cats prints/inkspots often appear but may or may not be on homozygous tobiano horses. Leg white often extends upward into elbow/stifle area and may go up over the hip to the top of the croup or even completely over the rear of the horse. Sometimes has a "bulls eye" patch of color over the tail head and a solid or bi-color tail in the middle of this). Can be very minimal with only high stockings showing and/or a small body patch. Dominant gene, must have a tobi or tovero parent.

    Overo...catch all term covering 4 distinct patterns. In almost all overo patterns the white is more of a horizontal marking...most notable in frames and splash whites. Good photo examples of both above. Overo patterns can be hidden in solid colored horses/breeds and are responsible for "cropout" horses....unknown whether such solids normally have a gene that suppresses the expression of the white or if there is a scarce gene that encourages it on occasion...or both.

    Frame is called frame because the white is typically on the side of the horse's body/neck and is "framed" by colored areas of the back and belly/legs. Frame markings are most often kind of jagged edged. Frame typically puts dark legs on the horse all the way to the hoof. Homozygous frame (OLWS) is a lethal white foal....usually all white (but not always...nor are all foals that are all white actually lethals...some are max expression other patterns). Can produce blue eyes...if a horse has blue eye(s) and is tested and is OLWS positive then even without typical markings you know the horse has a frame gene.

    Splash is as described.....horse looks like it was dipped in paint while hanging in a sling...blazes are typically wide and flat across the top and widen down over the muzzle. Splash puts leg white on that is usually level across the top and has smooth edges. Body markings with splash are also usually smooth edged and usually on the belly or very lower part of the barrel rather than on the sides of the horse. Also can produce blue eyes. If a blue eyed horse is tested for OLWS and is negative you can safely assume the horse is a splash white even if the markings don't show it. Have not seen info yet on differences in patterns shown by three different splash genes. Current info is that two of the three splash genes are lethal when HZ...have not seen info saying whether these cause lethal white type foals or if they lead to early embryo loss and no live foals are born with them. Splash can be very minimal with only socks or an odd star/snip seen or even just a partial blue eye.

    Sabino puts typically lacey, jagged, roany edges on markings....and can vary widely as there are multiple genes involved. Can vary from a few white hairs scattered here and there to a horse that is virtually all white. Usually pushes white away from the eyes so blazes tend to have "pinched" centers. Often puts a "mustache" on the horse...white face with dark on upper lip or in the corner of the mouth. Leg white is often seen with jagged or lacey edges and with the white often going upward in a point on the backs of the front legs and the fronts of the hind legs. Belly white is usually jagged, lacey edged and will be long the center line of the belly, often centered around the umbilicus. Very common gene and seen often in combo with others. On a frame for instance it will widen and expand body markings and often break up leg color into odd and weird shapes of white.

    Dominant white....anywhere from a bit of white to an all white horse...multiple genes involved and I'm not sure that there is a "typical" look to them.
     
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  7. coloredcowhorse

    coloredcowhorse Senior Member+

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    I've seen this description as well....that overos (all of them) look like a dark horse with white splashed onto them while tobi supposedly looks like a white horse with dark splotches added. Never made sense to me either since all of them can range from minimal white to nearly all white. My chestnut HZ tobi granddaughter of Smart Little Pistol....LOTS of white and LOTS of ink spots but her "tobi" markings are pretty small actually...colored head with blaze, small chest shield and small flank markings....all her other markings are ink spots and she's very much more white than colored. And my minimal splash looks like a QH....4 little socks, smudge of a star, 1.5 x 3 inch rectangular snip that runs to one nostril and a fleck of blue in one eye that you have to look to see.
     
  8. Shannon

    Shannon Senior Member+

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    I think what she means is that tobiano looks like a horse who was originally white, but with colored markings, and a frame overo horse looks like an originally colored horse with white markings. I get what she's saying, but it's hard to put into words :) It's not a matter of "lots of white" but whether it looks like the markings are white or colored. Oy vey I sound like a crazy person :)
     
  9. ACCphotography

    ACCphotography Senior Member+

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    I agree Shannon. I used to see it that way as well. You can learn that way as you develop an eye for it. It's just not very reliable.
     
  10. Fancy That

    Fancy That Senior Member+

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    Does my tobiano Shetland look like a 'white horse with dark splotches painted on it' ? :) I do understand the old wives tale, because if you take a "common/textbook" example of the pattern in a moderate/loud expression.....the saying is fairly true :)

    Its when you get to the extreme ends of miminal expression or maximum expression, where that old saying doesn't hold water.

    Mine is a minimal tobiano (thus, she doesn't look like a "white horse with dark spots painted on " )
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