Virginia Tech Researchers Study Asthma Using Horses

Many medical studies involve laboratory animals, but when it comes to research on asthma, no creature provides a better model than the horse. Veterinarians at Virginia Tech believe our equine friends might help humans who struggle to breathe.

Humans have a long and often loving relationship with horses. They've carried us on their backs, helped us haul heavy loads, and now it seems, they could provide clues to help us treat asthma. That's because horses are subject to a condition called equine heaves.

They're about the only animal that has a very similar condition to human asthma," explains professor Virginia Buechner-Maxwell. "They'll have this disease once they've been diagnosed for life, and human asthmatics struggle with that too. If it's not well managed, your airway is more inclined to constrict and constrict further. That's true both in human asthma and in horses."

Buechner-Maxwell sees hundreds of horses each year at Virginia Tech's large animal clinic. A fairly small number of horses have this condition in the mountains of Virginia -- maybe 5 percent -- but it's often triggered by mold and is more common as you head north. In Europe, up to half of all horses develop heaves. Horses are treated with the same drugs used in people, but when doing research, horses are far easier to study.

"When I have one of my horses in a study, I'm going to put them in a stall, and we'll have this regime for them every day, and I know that's going to happen," says Buechner-Maxwell. "You have a human in the study, the medication they're given -- they might take it differently, they might forget it one day. They might go out and take a hike in an area where there's lots of pollen, when they're not really supposed to be doing that. With the horses we have a lot more control."

Research is also safer on horses than on people. Since horses are larger, a couple of tubes of blood for testing is a relatively small amount for a horse compared to a person. Testing on horses also leaves researchers less prone to blood-borne disease like tuberculosis and HIV.

And, frankly, she says, horses tolerate certain tests better than humans: "We do take samples from the airways of horses. We can do that in the standing, lightly sedated horse, because their larynx is a little different. It doesn't spasm. It doesn't react. In humans they have to be under anesthesia for a lot of those procedures, because our larynxes are much more sensitive. They can spasm and cause constriction, so in general horses are easier to work with."

Finally, it may be easier to deal with the USDA when conducting animal research than to tangle with the FDA for human clinical trials. Dr. Maxwell hopes her research on the causes and treatments of recurrent airway obstruction in horses will also benefit people.