For veterinarians, Iditarod is all about the sled dogs

The Iditarod is one of the world's greatest endurance races. Each March, teams of sled dogs and their mushers set out to trek more than 1,000 miles through the Alaskan backcountry.

This year, not for the first time, a veterinarian was among the competitors. At the start and finish was a veterinarian who has led studies to improve sled dog and human health. Along the trail, as usual, several dozen veterinarians examined and tended to the immediate medical needs of the sled dogs.

The Iditarod commemorates a1925 relay by sled dogs and mushers to deliver diphtheria antitoxin to Nome to prevent an epidemic. The race also serves another purpose: maintaining the tradition of mushing. 

The musher

Dr. Tamara L. Rose moved from California to Alaska about five years ago, and a friend soon introduced her to mushing.

"It was just an instant attraction—I love dogs, I love the outdoors," said Dr. Rose, a mobile solo practitioner out of Fairbanks.

She said racing sled dogs is an adventure for her rather than a serious competition. She keeps 19 dogs in her kennel, including some that have retired, and she also has borrowed a few young dogs that a friend wanted her to train.

Dr. Rose is in her third year of racing. She started with shorter races to work up to the Iditarod this year, completing about three times as many qualifying races as she needed.

The ups and downs of racing the Iditarod still weren't what she anticipated, however. The trail was easier than she expected, but dog management was more difficult.

The trail groomers had paid particular attention to the route through a treacherous river gorge, she said, and enough snow had fallen to provide extra traction so sleds did not fall into the river. The route was rougher in an area full of tussocks where less snow had fallen.

For the most part, the weather was clear and cold—down to 40oF below zero. The problem came when the temperature rose. Then Dr. Rose had to stop often to prevent the sled dogs from overheating, allowing them to roll around in the snow. Mostly, Dr. Rose and her team alternated between six-hour runs and six- to eight-hour rest stops at checkpoints or along the trail.

Dr. Rose began the race with 16 dogs, seven of which were forward leaders. Trail veterinarians examined the dogs whenever the team stopped at one of the checkpoints, and Dr. Rose dropped dogs that had pulled muscles or sustained other minor injuries from competition.

"It's up to the individual how much we dote on them," Dr. Rose said. "I'm probably a little more cautious than some mushers."

Dr. Rose dropped seven dogs along the way, including two leaders. By the end, four more leaders did not want to lead, although they continued to run enthusiastically.

Twelve days after starting the Iditarod, Dr. Rose crossed the finish line with nine dogs. Her team was 43rd out of the 55 teams that completed the race. Only one of her leaders was left, Hailey.

"You couldn't do this with regular dogs," she said. "They're bred to go, and to want to go, and they're bred to have this athleticism that's just amazing."

The researcher

Dr. Michael S. Davis has been studying sled dogs for years at the Iditarod and elsewhere. His recent research has focused on trying to understand sled dogs' endurance and helping prevent the gastric ulcers that exercise induces in them.

"It was identified pretty early on that gastric ulcers were about the most serious health concern that these dogs had," said Dr. Davis, director of the Comparative Exercise Physiology Laboratory at the Oklahoma State University Center for Veterinary Health Sciences.

Dr. Davis and other researchers recently developed a practical medication scheme that appears to be effective at preventing the ulcers. They published a report in the March/April 2010 issue of the Journal of Internal Veterinary Medicine, but the editors allowed them to release the information to the mushing community before the 2009-2010 racing season.

Neither the Yukon Quest nor the Iditarod, the 1,000-mile-plus sled dog races, had any dog deaths due to gastric ulcers this year. One dog died during the Yukon Quest of silent cardiac disease, but no dogs died during the Iditarod for the first time in memory.

The researchers might never determine the causes of the gastric ulcers, Dr. Davis said, because they decided preventing the problem was more important.

"The other work that we've been doing is trying to break down and unlock the metabolism secrets of sled dogs, basically how they manage to run as hard and as long and as far as they do without getting totally fatigued," Dr. Davis said.

Most recently, the Diabetes Action Research and Education Foundation has provided funding for a study of the insulin sensitivity of sled dogs under various training conditions. Dr. Davis believes that sled dogs can run the way they do because they have an effective way of oxidizing fat for energy.

At the Iditarod this year, Dr. Davis also measured electrolyte concentrations and body water content of sled dogs before and after the race. 

Trail veterinarian

Dr. Caroline H. Griffitts began volunteering as an Iditarod trail veterinarian in 1993, and she was among the first members when the International Sled Dog VMA formed in 1994. Now she is ISDVMA president and three-time winner of the Golden Stethoscope award for most helpful Iditarod veterinarian.

Dr. Griffitts keeps volunteering at races mostly because she really enjoys working with sled dogs.

"The sled dogs are definitely different," said Dr. Griffitts, a mobile solo practitioner in Loveland, Colo. "They're very easy dogs to work with. They're generally extremely nice-tempered."

Dr. Griffitts enjoys the Iditarod in particular because the race allows her to see the beautiful backcountry of Alaska and to visit friends she has made at the villages along the trail.

During the Iditarod, groups of three to four veterinarians cover the checkpoints, some of which are simply a cabin or ghost town. Once the last musher passes through a checkpoint, the veterinarians there fly to a checkpoint ahead of the first musher.

At each checkpoint, the veterinarians set up shifts. Because the dogs run day and night, the teams can arrive at any time.

"Ideally, when a team comes into the checkpoint, we watch as the dogs run in—look for anybody who is obviously limping, holding back, not pulling, any issues," Dr. Griffitts said. "Obviously, if we see the musher is carrying a dog in the sled bag, we might have an injured dog."

The mushers don't stop at every checkpoint, but the veterinarians examine each dog whenever teams do stop. The veterinarians also care for the dogs that the mushers drop from the race for reasons such as orthopedic injuries, diarrhea, and pneumonia.

Aside from the Iditarod, Dr. Griffitts has been a trail veterinarian for a number of other races. She is chief veterinarian for a race in Wyoming. She also has visited Russia for the past two years to help with a new race there that is organized by an orphanage that keeps sled dogs.

Dr. Griffitts said she's seen many changes in the veterinary care of sled dogs since she began volunteering at races.

The ISDVMA has worked to promote research and share findings regarding the health of sled dogs. Research has found, for example, that sled dogs need about 10,000 or more calories per day while racing. Also according to research, vitamin E supplementation helps prevent myopathy in sled dogs.

Since the late '90s, the ISDVMA has organized a mandatory training seminar for rookie trail veterinarians during the week before the Iditarod. The seminar includes a day of hands-on training that includes pre-race physical examinations.

Dr. Griffitts said veterinarians who would like to volunteer for the Iditarod must have clinical experience and need to have graduated from veterinary college at least five years earlier. Information is available here. Information about the ISDVMA's 2010 symposium, Sept. 30-Oct. 4 in Duluth, Minn., is here.