The first time Waji, a seven-year-old gelding, was put on the treadmill at New Bolton Center, he was nervous. But after a few times, he got the hang of it and took to it pretty quickly.
"Horses, unlike people, accept things," said Laura May, a staff member at New Bolton.
For the past three years, Penn's Veterinary School faculty at the Chester County facility have put hundreds of animals through thousands of miles on the treadmill, looking for both ailments and cures.
Waji is being treated with a new medication to determine if it can alter oxygen consumption and lactic acid production during exercise. Horses breathe anywhere from 100 to 135 breaths per minute at extremely high gas flow rates, explained Dr. Lawrence Soma, a veterinarian who specializes in medications. At that rate, special devices are needed to collect the breaths. But once gathered, it is instantly analyzed for content. Trace materials of glucose or lactic acid tell the staff if the horse is taking in enough oxygen as it runs. If it is operating at an efficient level, the treatment is working, and the horse is recovering.
"The current system in use allows us to measure oxygen consumption and carbon dioxide production on a continuous basis as the data is updated by the computer every second," said Dr. Soma.
But turns on the treadmill aren't always so scientific. Sometimes the horses run on it to stretch their legs or get a light workout if they are recovering from an injury.
The Jeffords High Speed Treadmill--one of only several in use at universities in the country and the only one built in Pennsylvania--enables veterinarians to examine horses and other animals in action. It allows horses to run as fast as 38 to 39 miles per hour.
Looking at animals while they are standing still can tell a physician only so much. Getting them up and running, when heart and respiratory rates are increased, tells doctors much more about injuries.
For race horses, "it's as close to racing conditions as possible," explained Dr. Ben Martin, director of the treadmill and an assistant professor of sports medicine. "We can actively monitor heart and respiratory rates."
The treadmill, which was installed three years ago, is in use five to six days a week, said Dr. Martin. Most of the patients are race horses, although "pet" horses have been examined, as have field dogs and even llamas.
Unlike humans, animals can't tell doctors what's wrong or where they are hurting. Putting them on the treadmill helps doctors find out what and where the problem is and how best to treat it.
If horses are a bit skittish when they start on a treadmill, they're more so when they get on the treadmill with a tube up their nose. The tube is an endoscope, one of the most valuable tools for examining a horse.
A small video camera at the end of the tube allows veterinarians to see a horse's muscles, blood flow and upper airway functions while in motion. The image of inside the horse's throat is projected onto a screen to allow doctors to see what's happening while the horse runs. It can also record the images so doctors can examine the film to see problems that aren't immediately recognizable.
"The horses don't mind it when they get up and running," said Dr. Eric Parente. The endoscope--which is also used by physicians to examine humans--is held in place by Velcro. The horse is warmed up on the treadmill for a few minutes; after resting, the endoscope is inserted.
"The horse's metabolism is more dynamic than when it is standing in place, and this gives us a better view of the entire physiology," said Dr. Parente. "It's like giving a stress test for people." He and Dr. Martin have examined more than 600 horses on the treadmill in less than three years.
The most unusual problem that Dr. Parente has seen with the scope is a condition he has found in only two of the many horses he has examined. A horse's epiglottis, found in the throat and made of cartilage and mucus membranes, faces forward. In these cases, Dr. Parente said, the epiglottis faced backward and would flap back and forth while the horse was running, inhibiting its breathing.
"We don't know what causes it," he said. "But we are looking at a way of treating them."
Men were holding down the patient who was having a difficult delivery. The doctor gave the mother anesthesia and prepared to operate on the fetus--right there on the farm, in the middle of the night.
The calf couldn't be saved, but the mother survived. The farmer was grateful. His cow could always get pregnant again. And while the veterinarian was there, another cow began to give birth, again with complications.
Just another typical day for Elaine Hammel, a veterinarian who makes house calls from Penn's New Bolton Center in rural Chester County, 40 miles southwest of Philadelphia. She is one of the center's 325 physicians and staff members who provide a variety of health care and services for animals.
Once a week, Dr. Hammel is the doctor "on call" who responds to emergencies at odd hours. She carries a beeper just like doctors who care for humans. She has been at New Bolton since 1968.
During the day, she and the staff and students visit farms within a 25-mile radius of the center, tending to horses, pigs, cows, goats, sheep--almost any animal found on a farm. There are births to monitor, inoculations to give, joints to splint and wounds to stitch. The spring, when most livestock give birth, is her busiest time.
"It's a little like James Herriot's books," she says, referring to the popular series that began with "All Creatures Great and Small."
"I can empathize with his books. They've had a large impact on veterinary medicine. I still get students who tell me they wanted to become veterinarians after reading Herriot."
Other faculty at New Bolton tend animals in a variety of ways, include the following: