Kyle Peveto

Horses were Don Thompson’s first love. Then came science.

For decades Thompson, 69, an equine physiologist, has dedicated himself to researching horses, even when grant money and attention were showered upon other fields of study.

“I got interested in science because of the pure search for truth,” Thompson said. “What is the truth? Explaining nature — how exactly does it work?”

After 38 years as a professor at LSU and the LSU AgCenter, Thompson retired in 2019, leaving a legacy of research on which other scientists continue to build. Other researchers, including Erin Oberhaus, one of Thompson’s former doctoral students, are following his example and building on his work.

“He was always in it for the science,” said Oberhaus, who has taken over Thompson’s lab. “He was never really interested in what was hot at the time or what was a fad.”

Horses became a part of Thompson’s life as a child. An old 190-acre dairy farm near his house in New Jersey was converted to a standardbred horse farm, and the owners’ sons were around his age.

The long, muscular horses, which race while pulling a two-wheeled cart and rider, caught Thompson’s attention. “It was like heaven for me,” he said.

Thompson began working at the farm, mucking out the stalls, at 12 or 13. When he was older, he helped break yearlings, training young horses to pull carts. Eventually, the trainers trusted him to exercise the horses on weekends, taking them out with a cart and jogging for 3 miles.

At Rutgers University in New Brunswick, New Jersey, Thompson studied animal science, and for a few summers he worked at horse racing tracks in the state. A 1973 honor graduate with high test scores, Thompson was offered a graduate assistantship to study at Colorado State University, one of the top equine science programs in the country.

At CSU he studied the effects of daylight on stallions’ sexual cycle for his Master of Science thesis. His doctoral dissertation analyzed the effects of estradiol, a major female sex hormone, and testosterone on castrated male horses.

“We were looking at what hormones control what,” Thompson said. “That was novel work.”

Thompson was hired as an assistant professor of animal science at LSU to teach and conduct research. He moved to Baton Rouge in the summer of 1980 with his family, his wife Melissa and two sons with one more on the way.

At LSU Thompson was impressed with his resources, which included a 150-acre horse farm and 125 horses. Thompson went to work, delving deeper into the study of hormones on horses.

In the ’80s, he studied whether certain growth hormone treatments would benefit young horses. The horse industry was divided on the treatments. Some thought the treatments would enhance performance. Others thought they could create deformed giants, but Thompson and his team found no real benefit.

In his experimental methods class, Thompson would stress to students that research was simple. Just seek the truth, he said.

“The students said, ‘That’s it?’” Thompson said. “But think about all the implications of that. All of a sudden money is not a question and all these other things are not a question. It is only what is true — to the best of our ability to define it.”

At one time Thompson assigned the class the book “Zen and the Art of Motorcycle Maintenance,” a favorite text. One message of the book, a focus on the search for excellence, aligned with Thompson’s research philosophy, said Oberhaus.

“In all things in life you should strive for excellence — not necessarily popularity and not necessarily what is considered success,” Oberhaus said.

Thompson studied an array of topics from his lab. He developed an inexpensive, simple way to measure insulin sensitivity in horses, one of his proudest achievements because of its practical use.

For decades Thompson has also studied the seasonality of mares and eventually devised a way to get female horses to ovulate in winter. Mares’ ovaries go inactive in the fall and remain that way until early spring. Because horses born in January or February have an age advantage in horse racing, breeders want their mares to become pregnant by mid-February so they can give birth the next January or February.

Thompson found a way to use inexpensive endocrine treatments that increase prolactin, a hormone Thompson learned was needed for a mare to begin ovulating.

Thompson lists these developments among his proudest achievements. Other scientists, including Oberhaus, continue to work on the foundation he built.

“It’s a great tool. All these are tools we use to increase efficiency, to make things happen the way we want them to happen,” Thompson said.

Though retired, Thompson still assists with research. Researchers and veterinarians from all over the world send him samples to analyze. At home he enjoys boating on the Amite River and building furniture for his family.

After nearly four decades at LSU, his absence is felt on campus and at the AgCenter.

“I appreciate all he has done for agriculture, and we miss having him around,” said Phil Elzer, director of the School of Animal Sciences.

Oberhaus and Thompson still talk regularly about research and life outside the lab. She considers him a father figure.

“That man has no arrogance,” Oberhaus said. “He truly loves what he does. He requires no recognition for it.”

Even though he requires no recognition, she said, he still deserves it.

Equine physiologist Don Thompson, right, spent 38 years at the LSU AgCenter studying horses. Erin Oberhaus, left, a former student of Thompson’s, is continuing his research. Photo by Kyle Peveto