What do you get when you take a formerly abused and neglected Hackney pony and pair him with two combined driving rookies? If the pony is Harpo and the drivers are Jennifer Keeler and husband David Harris, you get a successful CDE team.

Keeler, of Paris, Ky., grew up riding and now shows her Quarter Horse, Reilly, in the hunters. She’d tried some pleasure driving with Reilly, but Keeler and Harris enjoyed combined driving only as spectators—until Keeler met Harpo.

“When they started running CDEs at the Kentucky Horse Park, we would watch and were big fans, but we never thought about doing it ourselves,” she said.

Harpo, now 10, spent the first years of his life on a farm in central Kentucky. Neighbors complained about his condition and that of four other horses on the property. Then a stallion, Harpo would jump out of his pasture and terrorize the neighborhood, stealing hay and grain, eating lawns, tearing fencing and visiting mares.

“[Animal Control] would get a call from neighbors about a rogue pony,” said Keeler. “When they would come after Harpo, he would take off and jump his way back to the farm where he lived and stand there looking at them like nothing had happened.”

Animal Control officers caught Harpo in late June 2008, but his owner refused to claim him. With an overflowing shelter and zero prospects for the pony’s adoption due to his poor condition and behavior, Animal Control was left with no choice but to send him to Hagyard Equine Medical Institute in Lexington, Ky., to be euthanized.

Despite his fear and aggressive behavior, the staff at the veterinary hospital wanted to find a home for him. Madelyn Millard, of Goose Creek Stables in Lexington, answered the call.

“I went into the barn at Hagyard, they opened the stall door, and this little guy who looked like the dickens took a step back from the door and looked me up and down. He didn’t rear, spin, anything; he just appraised me, and apparently I passed inspection,” Millard said. “He is a survivor, but it took Jennifer to bring it out of him.”

Millard brought the pony home, where she christened him Harpo, short for Hackney Rescue Pony.

After being sidelined by a medical condition in early 2011, Keeler was unable to ride, so she spent her time just visiting Goose Creek Stables, where she boarded Reilly, and saw Harpo each day in his paddock. “You couldn’t help but notice him, and I remember thinking: ‘That pony needs a job. He is bored out of his mind.’ He was too smart and was just causing trouble. I went to Madelyn and said, ‘Why don’t you let me play with him for a while?’ The rest is history.”

Keeler began working with the 13.1-hand pony, who was barely halter-broke, getting to know him and the sport of combined driving simultaneously. After three months of training, she decided to try competing, and Harpo quickly demonstrated a natural affinity for the sport. Harpo also transformed Harris, originally supportive from the sidelines, into an avid competitor. He now serves as his wife’s navigator.

“David has fully thrown himself into this, and he and Harpo are great together,” said Keeler. “We are a team, and the fact that we can do this together is very special.”

Over the past two years, Keeler, Harris and Harpo have moved up the levels and are currently competing at preliminary. The pony’s racked up a string of good placings, including second in the Gayla Bluegrass CDE (Ky.), where Harpo also won the marathon championship. They’re now eyeing a move up to intermediate.

Harpo has attracted fans who follow his progress through his website and his Facebook page .

“There is something about his personality that grabs people and makes an impression,” said Keeler. “He’s captivating and incredibly smart—scary smart. He has a dynamic energy about him, and as his training is progressing, he’s learning how to use his energy in a positive way. We feel like this is our once-in-a-lifetime horse.”

Keeler and Harris hope Harpo can be an ambassador for his breed and, more importantly, inspire others to take a chance on a rescue. They’d like to compete in the U.S. Equestrian Federation National Combined Driving Championships one day.

“Some people have said to us that he’s too small to be an advanced level pony. At first we were discouraged, but we’ll just have to see. We like to think that it’s not so much about his body size as it is about the size of his heart, and he has more heart than any horse or pony I’ve ever known,” said Keeler