Page 106 - September2021

HAULING HORSES IN HOT WEATHER
Good air flow is important, so all the windows should be open to create a lot of cross breeze.
The temperature inside a trailer is always hotter than the temperature outside.
EQUINE HEALTH
by Heather Smith Thomas
Horses may suffer heat stress and dehydra- tion when transported in hot weather, especially if humidity is high and they
have trouble cooling themselves by sweating. There are ways a person can minimize stress
and fluid loss, however, with careful manage- ment before, during and after a trip.
Dr. Mike Foss (Alpine Veterinary Hospi- tal, Hood River, Oregon) says people need to realize that the temperature inside a trailer is always hotter than the temperature outside. Horses have been known to suffer heat stroke when hauled in hot weather. “They are basi- cally confined in a metal oven,” he says.
“Horses are amazing animals; they tolerate most of the things we do to them, but being hauled is stressful--and more stressful for some horses than others. A study I did several years
ago showed that horses lose weight during transport, mainly from dehydration. One horse lost 77 pounds on a 450-mile trip, and it wasn’t even extremely hot; outdoor temperatures were in the 80’s and 90’s,” he says. Horses usu-
ally aren’t drinking when they are in a trailer, however, and very few people stop and water their horses during a trip. Meanwhile, the horse is sweating, losing body fluid, and not replenishing it. He will suffer even more stress, weight loss and fatigue if he is unaccustomed to traveling and nervous and upset during all those hours in a trailer.
Carey Williams, PhD, Equine Extension Specialist/Professor, Rutgers University, says
an important thing to remember is that when horses are being hauled, their muscles are work- ing all the time. They are constantly moving,
shifting weight, and keeping their balance in a moving trailer.
“I tell people that the next time they are rid- ing on a bus or subway or any moving vehicle where they can stand up, they should try stand- ing and see how it feels, and how tired they are afterward. It’s not easy. Even though horses have 4 legs and it’s a little easier for them to keep their balance, their muscles are constantly working. This creates heat in the muscles and heats up their bodies,” says Williams.
Even if a horse is an easy hauler and doesn’t get nervous or upset in the van or trailer, his body is still heating up just because the muscles are working to stay balanced. “If you add that extra heat production, com- pounded by hot weather, the horse is at risk for heat stress,” she explains.
104 SPEEDHORSE September 2021