It has been stated that the brindle pattern can't appear in white, but I think people are not seeing the pattern correctly. They see the white areas, and think the pattern is in white. But what is actually happening, is that the longer hair in the coat-texturing of the brindle streaks is preventing the white hair from invading that area (or at least at first in the case of grays). The white is thus restricted to the areas where there are no brindle streaks, making it look like a white streak (between the darker streaks). In the case of gray + brindle, they will eventually turn white, but when they are young, the brindle pattern will be evident. In the case of roan + brindle, the pattern should be permanent. I suspect this may only work in the case of ticking or roaning (undocumented genetically at this time), because roaning has also been seen to interact in some cases to produce "coon-tails" and some of the roan striped patterns (see article on striping). I suspect this may not work in the case of the regular roan gene. Roan is dominant to dun factor striping on the body, so I suspect it would also be dominant to brindle striping on the body as well, and thus you would not get the white streaks from the regular roan gene. However, test breedings would be needed to confirm or refute the above speculation.
When I first saw pictures of Catch A Bird (picture at top of page), I thought he was an example of the above, until I received information on his production records. While there is evidence that there might be a brindle gene in horses, because the brindle pattern has been shown to be inheritable (especially in terms of coat texturing) in the case of some horses, there are also examples of horses with an outward appearing brindle pattern in which the pattern has not been reproduceable in the offspring. Catch A Bird (TB) has had approximately 40 foals of which none have had his pattern. However, several supposedly roan foals (4) have been produced, indicating he is a possible mosaic or chimera of roan and non-roan. If he is a mosaic or chimera, some sections of Catch A Bird's coat have been activated for roan, other sections for non-roan, producing a streaked appearance which resembles brindling. However, when his sperm cells are made, they contain either roan or non-roan, but not both together. This accounts for his producing either non-roan or roan foals, and points to the likelyhood that he might be an example of a mosaic or chimera.
Mosaic or Chimera: All animals have two genes (allelles) at the same locus, but usually one of them is switched off at a very early stage of development in the embryo, so that only one of the genes is active. However, in the case of some mosaics and chimeras, both allelles are left active, and the inactivation of one or the other seems to take place at a later stage of development instead, so that the animal can actually have two different genotypes for that locus present. In the case of coat color, one section of the coat will have one color genotype, and another section of the coat will have a different color genotype. In female tortiseshell cats, this phenomena has been used to describe the patches of red and black hair in the pattern. Remember, we are talking about colors that would be the result of being allelles of the same locus, not colors that would result from the action of genes at different loci (such as white spotting).
Mosaics or Chimeras will generally not reproduce their pattern. Even though the animal has two different colors evident on their body, they will not generally reproduce other animals with a similar pattern. Simplistically, when sperm or egg cells are made, oogenesis causes the chromosomes to separate, so that each sperm or egg cell only gets one-half. A sperm or egg cell will get one or the other of the allelles at a locus, but not both of them in the same sperm or egg cell. For example, in female tortiseshell cats, the black color will be passed, or the red color, but not both at the same time in one egg.
In some horses, even if the brindle pattern is the result of mosaicism or chimerism and is not reproduceable from a specific gene per se, the pattern might be reproduceable if the mosaic or chimeric condition can be duplicated. For example, in female tortiseshell cats, there is no gene for tortiseshell - the female cat is the result of a mosaic or chimeric condition of black and red, and she only passes either red or black. If she is mated to a black cat, any female offspring that got the black from her and the black from the tom will be black. But the female offspring that got the red from her and the black from the tom, will appear tortiseshell. Thus, the pattern can be duplicated, even though it is not the result of a specific gene per se. While it is not known if this is also possible in horses, it will be important to follow offspring of possible mosaic or chimeric horses keeping this in mind. Even though outwardly appearing brindle (phenotypically brindle), I am thinking of calling these types of brindle horses pseudo-brindles, to distinguish them from other brindle horses that would be the result of a brindle gene (genotypically brindle). I see no way of differentiating between the two until production records were available on the animal, as outwardly they would both appear brindle.
There is a new registry for brindle horses started by Anita Garza in 1998 called the Brindle and Striped Equine International. She is registering brindle, heavy dun factor, "netting", horses, zebra hybrids, zebras, donkeys, mules, ponies, etc. She says her registry will have a Register of Merit awards program. Contact her for more detailed information at 409-793-4207, e-mail, Anita Garza, 11819 Puska, Needville, Texas, 77461.
Some brindle horses can be registered with the IBHA as "brindle dun". They have had the category "brindle dun" since approximately 1971. Unfortunately they aren't able to produce a list of horses registered as this color since most occurred prior to computer searches being generally available. Visit their website for more information, or contact: (219) 552-1013, International Buckskin Horse Association, PO Box 268, Shelby, IN 46377.
The International Striped Horse Association started by Mary Jagow in 1988 has been closed in March 1999 as per Mary Jagow.
This slideshow was last updated January 2, 2000. To see if new pictures were added since the last time you were here, you may have to "refresh" or "reload" your screen. Remember, these photos in the slideshow are for informational purposes only, in order to educate people on how variations in the Brindle pattern can look. Most of these photos are copyrighted and cannot be reproduced without permission. There is a link at the bottom of the page to a photo that can be printed out and distributed to your friends if you wish. If you have trouble with the slideshow, the pictures can also be viewed through our Table of Brindles. The photos on the table, even though small, take a while to load because they are links to larger photos, and the larger photos are the ones that are being loaded. However, you can scroll down and read the table, and click on the unloaded photo box to jump to that larger picture if you wish. If it shows the photo as being not found, it is one of the photos I haven't completed yet.
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Click this type to go to our section of unnamed horses, and click each picture to continue. Please see if you can recognize any of these horses. The first three unnamed photographs were probably taken around 1978 to 1980 by Chuck VanHorn of Cave Creek, Arizona, to make a slideshow presentation demonstrating various colors and markings for the International Buckskin Horse Association. Unfortunately, names of the various horses were not recorded. The next two unnamed photographs were taken of Bavarian Warmbloods in 1989 by Evelyn Simak. If you recognize any of these horses, please contact us.
Brindle has occurred in such diverse breeds as Arabians, Thoroughbreds, Mustangs, Quarter Horses, Bavarian Warmbloods, Russian Horses, Spanish Horses, and supposedly also in the Netherlands. Sometimes the pattern seems to be composed of dark hair (black or brown), sometimes of white hair (roan). Since so little information is available on the Brindle pattern in horses, we are not sure if they are from the same gene or not. There could be several genes involved, producing similar patterns (much as pinto/paint spotting can result from several different genes). Many people confuse Dun Factor markings (stripe down the back, barring on the legs) with brindle. Indeed, there have been many examples of horses that were probably carrying both genes. However, the Russian cab horse, and the Brindle mare on the far right in the photo you can click the highlighted type to see, do not have any Dun Factor markings whatsoever. Click highlighted type to compare Dun Factor and Brindle. Brindle horses also have texturing in their coat, similar to that seen in some Appaloosa horses. The pattern seems to be inheritable, especially in terms of coat texturing, but the expression of the darker or more intense pigment to make the pattern visible is highly variable, and even varies with individual horses seasonally / yearly. However, before we start drawing too many conclusions about the pattern, we need to locate more examples for a study.
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Click this type for a picture of a Brindle Horse with contact information you can print.