NEW RIVER, AZ - The stallion circles and plods, whinnies and trots across the pen.
"He's doing better," says his trainer, who notes you can still see his ribs sticking through his rib cage.
Outsiders are always amazed at how quickly they recover -- a 1,500 pound animal near death just a few weeks ago is showing few signs of the struggle and the abuse he's suffered.
It's a familiar scene at Arizona Equine Rescue in New River. Each week, volunteers are called out to corral a stray horse found wandering through a neighborhood or more likely, lost and starving in the desert.
No one has exact numbers, but experts say there are likely hundreds of horses recovered in the Sonoran Desert every year that are used to run drugs from Mexico.
"They're used as vehicles," said Soleil Dolce of Arizona Equine Rescue. "And when they're done with them, they're just abandoned."
More often than not the animals are emaciated and dehydrated. They often have other problems too, from scars and chafing from the heavy loads, to illnesses which often go untreated in Mexico.
Many of the animals also show signs of abuse, Dolce said. They often are fearful around humans.
The horse problem is not a new phenomenon, but it's one which has steadily grown in recent years, exacerbated by a struggling economy.
Rescue groups offer one of the few outlets when border agents find the animals in the desert. But as unemployment grows and foreclosures hit hard, rescue groups often watch funding dry up, even as more horse owners turn to them, unable to care for their animals anymore.
The costs mount for organizations, from veterinary bills, to feed and transportation costs.
Still, many organizations manage to rehabilitate the horses, often finding quality breeds among the equines which merely serve as pack mules. Some of those animals even return to the desert to be used in mounted patrols, tracking some of the very smugglers who abandoned them.
Copyright 2011 Scripps Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Did You Hear?
A polite young girl in Ohio recently wrote an apology letter to her police department after she accidentally called 911 from a disconnected cellphone.
Officials at a Colorado school are accusing the boy of sexual harassment after he kissed a classmate on the cheek.
Feeling chilly? Here's cold comfort: You could be in East Antarctica which new data says set a record for soul-crushing cold.
More Black Canyon News
A man who stepped on an explosive device and lost part of his left leg outside a New River home earlier this month talked to ABC15 about what happened.