A horse dozing in a green pasture under the summer sun certainly conjures up a peaceful image in our minds. Ah, mid-day naps can be a wonderful thing. But when a seemingly healthy horse seems to suddenly wobble and buckle at the knees, and then snaps back to alertness, it may remind you of falling asleep in a high school science class lecture – brief, but surprising.

Narcolepsy in humans has been studied to identify four indicators of the disease. Excessive daytime drowsiness may include periods of rapid eye movement (REM) sleep during waking consciousness. Cataplexy is a sudden, temporary loss of muscle tone while conscious. The two more serious developments would be sleep paralysis and daytime hallucinations or terrifying dreams. While the sleep paralysis and hallucinations are impossible to diagnose in a horse, given they can’t tell us, the excessive drowsiness and cataplexy can show up in horses.

In equine narcolepsy, the excessive drowsiness – and sudden REM sleep – usually happens when the affected horse is at rest, inactive such as in their stall or pasture. Their head will drop low and the front legs will spread for balance as their hind end seems to sag. Their eyes may close slightly and you can see movement, which is the REM. Most horses will be able to remain standing, appearing to be under the effects of a strong tranquilizer, until the episode passes and they resume their normal, conscious level.

Cataplexy is a more serious development, which the horse can actually fall to the ground. It can happen at surprising times, while walking or resting. Their knees will buckle, causing them to stumble or stagger and sometimes collapse. Some narcoleptic horses may experience cataplexy at feeding time, during a bath, after exercise, leading them from their stall or even while just stroking their head and neck. Most horses regain control within minutes and return to normal, so recommendations are to just stand back and let it run its course.

It doesn’t seem that a lot of research has been done on equine narcolepsy. A Google search will bring up articles published in 2011 and earlier, and they seem to contain the same basic information. It can be difficult to diagnose, is without a cure, and treatment options are limited. Many times, symptoms resemble hyperkalemic periodic paralysis (HYPP) that more horse owners and veterinarians may suspect that rather than narcolepsy.

Jessica Stalder, of Blue Grass, Iowa, and her American Quarter Horse mare, A Modern Zippo, learned about equine narcolepsy firsthand a few years ago. Jessica showed the 1998 mare in AQHA all around youth competition from 2001 to 2007, earning an AQHA Youth Championship, before entering into her amateur years. She bred her in 2009 and quit showing later that year.

“We first noticed something was off with ‘Twiggy’ shortly after she recovered from a bout with West Nile,” Stalder said. “We would see she had some involuntary muscle spasms in her left hip. Shortly after that we suspected she was falling down when we would see minor cuts and abrasions on her legs and sometimes on her sides.”

Then they actually saw her fall.

“One instance I remember particularly was while waiting for Showmanship during the (Iowa) Seven Day Run,” she recalled. “We were along the rail in the arena waiting for the class to start. It was pretty warm, and Twiggy was relaxed. She started holding her head lower and lower, then her knees started to wobble and she actually began to fall. This seemed to startle her and she stood back up, with a surprised expression.”

Stalder said they suspected narcolepsy once the physical symptoms started to manifest.

“Our vet hadn’t had any experience with it but another vet saw her fall and suggested narcolepsy,” she said. “There weren’t really any treatment options, it just became something we lived with; nothing was planned medically unless her condition worsened.”

Stalder and Twiggy continued on with normal life, or what had become normal for her. There was no real great change to Twiggy’s life.

“Except she would be so unpredictable when standing for long periods of time,” Stalder said. “We quit showing her in the large Halter classes that would take so long. We always wrapped her legs at night. We also started to recognize certain triggers, such as warmer days or long days at shows where we were in multiple classes. It could show up during her overly relaxed moments, like when she was turned out in her paddock. One time she was basking in the warm winter sun and fell right down into a snow pile. That was rather comical.”

Stalder’s veterinarian, Doug Anderson, remembers the mare but says nothing out of the ordinary really occurred with her narcolepsy.

“I guess it falls under the weird and wonderful category,” said Anderson.

The mare continued to be healthy and show as a performance horse. She even carried a foal, with a filly born in 2010.

At the time, and even to this day, Anderson says he hasn’t had much experience with equine narcolepsy other than Twiggy.

“I have a client with a half-Arab who would stand in its stall and just fall to the ground, for no apparent reason. It would stand right back up again. We sent it for neurological testing, but nothing was ever positively identified. I haven’t seen the horse in at least a year and a half,” said Anderson.

The Kruchten Family, of Waunakee, Wisconsin, purchased Twiggy from Stalders in 2011 for their youth daughters, to show, with guidance from Jeff Greaves, an AQHA Professional Horseman from Galva, Illinois.

“We knew about the issue when Kruchtens purchased her,” he said. Kamryn started on her in the Novice Youth classes under a lease agreement. With two more daughters coming up, they purchased Twiggy. Kamryn and Twiggy earned over 178 AQHA points in novice youth and youth all around events. Kamryn shared the saddle with younger sister, Rachel, who racked up nearly 400 more Youth and Novice Youth points for her record. Even little sister, Kaylyn (Lou), started with Twiggy in the Small Fry classes.

“The narcolepsy was pretty much a non-issue for us,” explained Greaves. “It was more just a maintenance item. We knew it would show up when she was tired, so we were just aware of it at the horse shows and took precautions in her care.”

Twiggy always got extra bedding in her stall, at home and at the shows.

“Limestone floors were more of a problem for her,” Jeff continued. “When she would fall, she would scrape her knees and ankles, so she had scars and sores. The limestone would be a rougher surface and tear open the sores, so we would always wrap her legs at the shows, and make sure her ankles were covered to protect them.”

At home, Twiggy would stand in the same spot in her stall, and she would fall in the same spot in her stall.

“Every couple of months, we would have to put a couple of stitches into her head,” Greaves said matter of factly. “Then she’d move and stand in a different spot in her stall and might not bang her head as much. Mostly, it was her knee and ankle sores that were slow to heal if they broke open. So we’d keep them greased up to try to prevent that skin from breaking open, since it took three to four weeks to heal.”

Greaves said he has only seen the mare go down one time when someone was sitting on her, and it was when they were just standing for quite a period of time.

“She’s never fallen when someone has been riding her; we’ve never felt that was a threat or even a potential problem,” he said. “Knowing about it, you could anticipate it. If you watched, her eyes would close, then her head would drop lower, then she’d sort of fall to her knees.”

Twiggy would jump right back up, and appear a bit startled, but she didn’t just fall flat.

“There were no big tricks to it,” said Greaves of the narcoleptic mare. “It wasn’t hard to keep her, it was just something we took care to manage.”

Her affliction doesn’t appear to have had any influence on the mare’s personality or attitude.

“Actually, the narcolepsy sort of fit her,” smiled Greaves. “She is a quirky little mare, so it just went along with her. I remember when we first got her, there is one corner of my arena where she would spook, every time she would go by it. Every time. For a year. Actually, we have her daughter, her only foal. That mare spooks in the same corner too.”

Greaves describes her as a cranky old mare.

“We never had a narcolepsy issue with her while trailering, but if we were on the road for more than six hours she would act colicky when she came off the trailer,” he said. “We’d walk her for about 15 minutes and she’d come out of that and be back to normal.”

But Twiggy was great with the kids.

“She loved to go show,” he admitted. “At home, she would spook all day long. But she never was spooky at a horse show. She could have a bad practice session, but when those girls walked into that pen to start a pattern, she was on. In fact, that’s how we decided when it was time to retire her. We were at a show last summer, and for the first time, she didn’t want to show. We knew then it was time for her to be done.”

Retired now, she spends her days in a neighbor’s pasture near Greaves training facility just outside of Galva.

“She’s not social, she doesn’t want to be turned out with another horse, but she has to have one turned out next to her

or she walks the fence,” Greaves said. “She was always a little weird, but, as a trainer, I appreciated her and the way she took care of the girls.”

After dealing with Twiggy and the narcolepsy, Greaves said he’s talked to people who have had the same issues with horses in their barn and they’ve shared their experience and accumulated knowledge on a topic that’s not widely discussed. Because of the lack of a definitive diagnostic test, it’s difficult to say how common the ailment is in equines. It’s said to be rare, however when brought up in conversation it’s not out of the question to discover someone that has seen a horse with the condition.

“I know of a big hunt seat horse that would go down while they were braiding,” he said. “So they couldn’t tie it short. But the horse showed just fine, I think it’s still out there showing.”

The narcolepsy was never an obstacle to Twiggy’s show career. The maintenance came more in her stalling and downtime, so to speak. Kamryn and Rachel showed her in Halter, Showmanship, Horsemanship, Western Pleasure and Trail. She earned four Superior Awards along the way, three Reserve Champion titles at the 2013 AQHA Region 3 Championships, and nationally qualified for the Youth World Championship Show in three events in 2015.

Greaves said they used to joke that he felt Twiggy was such a solid Trail horse that once he prepared her for the pattern, he could put a monkey in the saddle and she would show.

“We sort of proved that when Rachel quit showing her and got on a new horse,” he laughed.

Greaves said they learned just how much Rachel depended on Twiggy and how much the mare did take care of her now that she’s riding a new horse.

“Rachel told me she didn’t think she could ever show another horse other than Twiggy. When I asked her why she felt that way, she told me it was because she thought Twiggy did 90 percent of the work. Turns out, she was right.”

Twiggy officially retired from the show arena in 2015, with over 800 AQHA points on her record, and a million memories for the lucky girls who loved her and were privileged enough to call her their show partner.

WHAT DO WE KNOW ABOUT EQUINE NARCOLEPSY?

“It happens, it is true,” said Scott McClure, DVM, PhD, Associate Professor, Veterinary Clinical Sciences at Iowa State University Veterinary College of Medicine. “In miniature horses, there have been reports of a genetic component when it shows up in youngsters.

But most commonly, when it does appear, it shows up sporadically in a potluck of breeds in mature horses without specific genetic links.” McClure says the cause of equine narcolepsy is not exactly known, however it is suspected that environmental issues have some correlation to the disease.

“The triggers are commonly linked to environmental issues, such as sleep deprivation,” he explained. “The horse will seem tired, then the knees begin to buckle and that’s the typical symptoms that you see.”

Horses require about 4-6 hours of good sleep, and they also rest intermittently throughout the day. The horse may have musculoskeletal issues, such as arthritis, so that they do not want to lay down to sleep, thereby preventing them from getting that good amount of sleep and rest. In show horses, when the horse is being ridden for long periods of time or in the middle of the night, and perhaps also spending a good amount of time tied in the stall, to prepare for the competition will probably not get the rest and good sleep they require. Of course, stress is always a contributing factor in the horse’s overall health and well-being.

Dr. McClure said diagnosis of equine narcolepsy is done by the “rule out” method. Horses that collapse during exercise are often the result of cardiovascular problems and are very different from narcolepsy.

Eliminating musculoskeletal issues or injuries, potential tumors or brain infections such as viral encephalitis or EPM is a good starting point. If possible, placing the horse under observation with a 24 hour security camera for a few days can help you determine their rest and sleep patterns, and if they are actually laying down to sleep, or if you are seeing them collapse in a narcoleptic state.

There are drugs THAT EFFECT neurotransmitters, that can be used to treat narcolepsy. However, they would probably not be legal for competition and, while they may help, they are often times not ideal. Correcting any environmental situations and treating any physical issues that may have been interfering with the horse’s ability to rest and get good sleep are the first steps you should take when dealing with equine narcolepsy. Beyond that, attention to maintenance and care will help ensure the horse’s health and safety.