Older Horses: Decreased Thermoregulation During Exercise

Senior horses have a propensity for developing hyperthermia, or elevated body temperature, when exercising.

No account yet? Register


Experience and instinct tell us to condition older horses carefully, keeping a close eye on how they handle their workouts. A team of researchers at Rutgers University confirmed these instincts when they examined senior horses’ propensity for developing hyperthermia, or elevated body temperature, when exercising.

Led by Kenneth McKeever, PhD, FACSM (fellow of the American College of Sports Medicine), a professor in the Department of Animal Science, a team of researchers examined older horse’s propensity for developing hyperthermia, or elevated body temperature, when exercising.

In previous studies scientists have examined horses’ ability to thermoregulate during physical exertion, but they had not evaluated the older horse population specifically. In the current study researchers evaluated relationship between physical exertion, thermoregulation, and plasma volume in six younger (7 to 8 years old) and five older (mid-20s) unfit Standardbred mares working on a treadmill.

The horses exercised until their core body temperatures reached 40°C (104°F, the normal temperature for an average adult horse is 99-101°F or about 37.2-38.3°C). The investigators monitored the animals’ core, skin, and rectal temperatures, as well as heart rate, every minute during and immediately post-exercise. They also collected blood samples from the horses before their body temperatures reached 40°C, at 40°C, and every five minutes until 10 minutes post-exercise, later analyzing the samples for packed cell volume, lactate, and plasma protein. Sweat loss was also estimated using body weight as a reference

Create a free account with TheHorse.com to view this content.

TheHorse.com is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into TheHorse.com.

Start your free account today!

Already have an account?
and continue reading.


Written by:

Freelance journalist Natalie DeFee Mendik is a multiple American Horse Publications editorial and graphics awards winner specializing in equestrian media. She holds an MA in English from Colorado State University and an International Federation of Journalists’ International press card, and is a member of the International Alliance of Equestrian Journalists. With over three decades of horse experience, Natalie’s main equine interests are dressage and vaulting. Having lived and ridden in England, Switzerland, and various parts of the United States, Natalie currently resides in Colorado with her husband and two girls.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from TheHorse.com

Sponsored Content

Weekly Poll

sponsored by:

What do you think: Can pituitary pars intermedia dysfunction (PPID) be managed by medication alone?
156 votes · 156 answers

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with TheHorse.com!