Brindle is a rare coat seen in horses. The result is where the horse has a lighter coat colour with a darker colour striped on the body. The stripes are uneven and rigid in nature. Brindle horses can range from a complete body brindled to only a small area that is brindled.
One form of Brindle is when a mare is pregnant with twins of two different colours. Early in the pregnancy the two embryos will fuse together, resulting in a horse with two different sets genes which is called Chimera. Not all Chimera horses are Brindle, others are called Mosaic Chimera which have a ‘patchy’ look.
White Brindle, or Reverse Brindle, is opposite of the usual Brindle where a dark horse has a white brindled pattern. No White Brindle horses have ever tested positive for Chimera which means that there is other factors involved in causing this pattern on some horses. One form of White Brindle is associated to Roan and/or Rabicano.
Some White Brindle horses test positive for Classic Roan. For unknown reasons the Classic Roan doesn’t present in the usual phenotype and instead expresses it’s self in a Brindle pattern. These horses have gone on to produce normal phenotype Classic Roan horses. Rabicano horses can also express the skewed Brindle pattern with their white ticking. Catch A Bird, a White Brindle Bay Thoroughbred, is an example of a skewed white ticked pattern producing normal phenotype offspring (the Catch a Bird Roan has not yet been genetically discovered).
Brindle patterns can be seen on Dun horses at a higher rate then other colour genes. It appears that the Dun gene can add the Brindle pattern to the coat similar to how it adds Dun Factors such as the Dorsal Stripe, Leg Barring and Neck and Shoulder Stripes.
Some horses that have Brindle patterns on their coats that appear to be caused by Sooty. Sooty can cause many striping patterns often mimicking Dun. This includes the false dorsal stripes and leg barrings. On a rare few Sooty horses, a brindle pattern can be seen.
Some Grey horses will develop a brindled effect while going through the greying out process. It appears to be a skewed method of greying out where instead of dapples forming the brindle stripes form. The Grey Brindle horses will eventually grey out of this effect.
Genetic Disease Brindle
There is now a form of Brindle that has been genetically discovered and is inherited through generations. However, one can consider this a genetic disease as much as it is a colour pattern. The genetic disease Brindle causes numerous health issues including problems with the skin, eyes, teeth and hooves. It is a dominant gene effecting only female horses, male horses die in utero with 1 copy of the allele and it is homozygous lethal in both sexes.
Check out this album to see pictures of Brindle horses:
Brindle HorsesCheck out this album to see pictures of Brindle horses!