07/01/2010 11:00PM

A brindle earns its racing stripes

Remark is one of only five confirmed brindle Thoroughbreds, and the only one known to race.

Here's a sure bet: Remark is the most unusual Thoroughbred you'll ever see.

Did someone pour bleach on her? Does she suffer from a skin disease? Is it a birthmark?

Yet when I saw her hind end sashaying around Kiaran McLaughlin's shed row at Belmont Park, I knew exactly what Remark was - a holy grail among those who study equine color.

Remark is a brindle Thoroughbred.

J. Sharon Batteate, considered the foremost expert on brindle horses, knows of only four other confirmed brindle Thoroughbreds (there have been a handful of unconfirmed cases). Remark, however, is the only brindle Thoroughbred known to race.

On her left side, Remark is unremarkable. The dark bay or brown filly's face is long and slim, and her eyes - separated by a nondescript star - are kind and curious. A small splash of white marks her left hind ankle, yet is nothing notable.

But her right side - well, that's the stuff of dreams. White stripes drip across her coat in odd patterns - Jackson Pollock-like splatters lacing her hind end, below her withers, her barrel. A few small spots dot her neck.

Brindle Thoroughbreds are so rare that Google shows only about 100 matches for the term, many devoted to the most documented case, Catch A Bird (1982-2007). Catch A Bird, a dark bay or brown New Zealand Thoroughbred, was covered with white stripes, fore and aft, but he never raced.

Nor did two confirmed American brindles, both of whom sport dark stripes. In California, a 20-year-old light chestnut mare by Teddy's Courage has a few dark red stripes along her hind end on the left side. And Slewcy's Gale, a 15-year-old dark bay mare by Slew City Slew at the Kentucky Horse Park, has prominent, raised black stripes visible on her right side.

Odds are good there have been others, horses whose patterns went undocumented or whose brindle markings were dismissed as something else.

The difference with Remark is that she is a well-bred, highly promising 3-year-old filly, bred and raced by Darley. Her sire is Distorted Humor, and her dam is the graded-stakes-winning Kris S. mare Krisada. Krisada is out of the highly successful graded stakes winner Funistrada.

McLaughlin said he had never heard of a brindle horse. But he chuckled when saying she has been a topic of conversation - and much curiosity - since her arrival at his barn.

"We really didn't know what it was," said McLaughlin's assistant, Artie Magnuson "We had a lot of people asking us, 'What did you do for that skin disease?' "

15px;">Slewcy's Gale, a 15-year-old dark bay mare, lives at the Kentucky Horse Park.

While they probably don't help her, Remark's stripes don't seem to slow her down. In 6 starts, she has earned 3 seconds, 2 thirds, and $37,650. Her most recent effort came June 13 at Belmont, where she was sent off as the 2.70-1 favorite in a maiden special weight. Even jaded horseplayers took note as she bounced by in the paddock, her neck bowed and stripes bright.

That day, Remark gained the lead in the homestretch after racing four wide but missed the win by a head. She was nestled inside another horse - hence ruining what could have been a striking photo.

Remark's next start has not been decided, but McLaughlin said she may race at Saratoga.

Brindle horses of any breed are so rare that studies have not been done to fully understand the genetic reasons behind them. However, stripes on just one side of a brindle horse point strongly toward chimerism - two embryos fusing early in pregnancy.

When scientists have conducted DNA tests on the stripes and the base coat of such horses, those tests have identified the DNA of two distinctly different horses.