A retired racehorse, Metro Meteor, has been taught to paint by his owner. Artist Donna Bernstein visited Metro, who has earned more in painting than in racing, to collaborate. (Christopher T. Assaf/Baltimore Sun video)

Metro Meteor, whose abstract paintings rapidly are becoming an art world sensation, might be just a horse. And the 11-year-old bay, like all equines, has a hard time distinguishing reds from greens or browns.

Yet Metro's original watercolors have become the runaway favorite at a regional art gallery. He has racked up a combined $130,000 in sales for his paintings and, through a separate licensing agreement, a line of home-decorating products.

"Metro is by far our best-selling artist," said Peggy Rock, the director of Gallery 30 in Gettysburg, Pa. There, the horse, who is stabled here in Frederick County, has sold 80 large paintings and 300 miniature works at prices ranging from $80 to $850. "He probably has double the sales of our second-best-selling artist."

As the attention of the horse-loving world turns Saturday to California Chrome's attempt to win the Triple Crown, Metro is proof that racehorses past their prime might not all need to be put out to pasture.

In his heyday, Metro earned $300,000 in purses during a racing career that stretched from 2005 through 2009, owner Ron Krajewski said. He was trained by Linda Rice, who recently prepared Kid Cruz for the Kentucky Derby and the Preakness. Metro even ran on grass at Belmont Park, where he excelled in races of six furlongs.

His advice for Chrome?

"Metro thinks that California Chrome should save some for the end," said Krajewski, tongue firmly in cheek. "He shouldn't use it all up too early. It's a long race."

Metro isn't the first animal ever to apply paint to paper and call it art. There have been art-making elephants and frogs. Cows have made salt lick sculptures. Many of the animals' creations have been auctioned off to raise money for zoos or other charities.

But few if any of these creative quadrupeds have been represented by an art gallery alongside their human counterparts.

Rock said she never hesitated about displaying and selling Metro's artworks, even though she was aware that she might get resistance from customers or artists.

"There have been a few laughs, but that's never been a concern for us," Rock said. "We also lost one of our long-standing artists. She was probably our next best-selling artist after Metro, and she didn't think that his art should be on our wall. But every other one of our artists has been very supportive."

Doubtless, part of the appeal is Metro's back story. Krajewski uses about half of the proceeds from his sales to pay for an experimental treatment for a knee ailment that once threatened the horse's survival.

"Metro's paintings saved his life," Krajewski said.

The remaining funds are donated to a charity for retired racehorses

"Ron's generosity has been absolutely extraordinary," said Dot Morgan, founder of the Ohio-based New Vocations Racehorse Adoption Programs, who said that Krajewski has contributed more than $60,000 to the organization in the past 18 months.

"What he has allowed us to do is to take injured horses that previously we might have had to turn down because it would take too long to rehabilitate them. Now, with this funding, we can take six months to treat them even before we start retraining."

Here's a portrait of the artist as a middle-aged horse:

Four days a week, Krajewski leads Metro to the stall devoted to his artwork, which he and the owners of Motters Station Stables in Rocky Ridge have dubbed "Studio Six."

There's a table that contains watercolors in a vast array of hues: emerald greens, rich reds and stark whites. There's a paint-splattered easel, and a pallet of the 300-pound paper ideal for watercolors. Most important, there's a big blue treat bucket.

Krajewski, who is also an artist (he specializes in pet portraits), drops a treat into the bucket. After Metro scarfs it up, Krajewski dips the brush in a color that he has selected and places the handle in the horse's mouth. Bobbing his head up and down and side to side, Metro swipes the brush over the canvas.