Are Your Horses Getting Enough Sleep?
by Brian de Lore
Published 23 December 2015
With two Premier race days at Ellerslie followed by two more at Trentham, the annual mid-summer migration of racehorses targeting feature races is about to commence.
Horses will converge on those centres from the deep south, the far north and everywhere in between. They will arrive after a rigorous preparation, perhaps a very long float trip in heat and then before stabling in unfamiliar surroundings.
The question begs, will that combination of circumstances affect some horses sleeping patterns and as a consequence their performances? Race form results from a delicate combination of fitness, luck and numerous other incidentals, and sleep deprivation is not just an equine reality, but a factor never considered.
Considering the significant advancements in veterinary science, the science of feeding, training methods and
Several studies in the USA and Europe have been conducted on horse sleeping patterns but not specifically thoroughbreds. As in humans, experts have determined that some horses suffer from sleeping disorders.
Unlike humans, horses are considered ‘cathemeral’ which means they are neither nocturnal nor diurnal but do a mixture of sleeping and waking in both daytime and night-time hours. Evolved from animals of prey, the horse has a well-developed instinct to ‘take flight’ if danger threatens.
That’s why they can sleep standing up. In the stable resting in the ‘stay apparatus’ position, usually with the head pointed towards the stable door, a horse will rest his muscles, reduce fatigue and doze off. It’s not a deep sleep, but if danger threatens, nature has readied it for a quick escape.
Dr. Joe Bertone, DVM, MS, Dipl. ACVIM, professor of equine medicine at Western University of Health Sciences’ College of Veterinary Medicine in Pomona, California, describes this state as ‘diffuse drowsiness’ which is the first of four phases of sleep
Diffused drowsiness is associated with the horse standing square, head and neck slightly lowered, the lower lip drooping and the ears and eyelids relaxed. “The next phase is the ‘intermediary,’ and then there is ‘slow-wave’ and ‘paradoxical’“ says Dr. Bertone in his journal, conducted from research carried out in the 1960s and 70s.
”In the intermediary phase, just before lying down, horses become alert and examine their environment. Then they lie down if they feel safe enough to do so. Once lying down, horses experience diffuse drowsiness again and if at ease with their surroundings, enter into slow-wave sleep.
“When drowsy, horses often lie sternal (on their abdomen with tucked-under legs) with their head slightly raised; they can be easily aroused from their slight slumber at this point. In general, horses will then lie on their side to move into slow-wave sleep.
“Importantly, paradoxical sleep requires a horse to lie down because all muscles relax,” says Bertone. During this phase, rapid eye movement (REM) sleep occurs, and the horse’s brain is very active, but he is essentially paralyzed; he generally remains in the sternal position, but moves his head to the side and to the ground to remain propped up
“Most of this sleep is amassed by ‘nickel and diming,’ meaning horses can snooze for short periods—about 15 minutes at a time. Those minutes all add together to comprise that overall sleep total. Horses can go weeks without a full sleep cycle when needed, however, which is in direct contrast to humans who require prolonged periods of undisturbed sleep to function optimally.”
In a separate paper, Dr. Bertone concluded that horses on a daily basis needed approximately two hours of diffused drowsiness, three hours of slow-wave sleep and less than one hour of paradoxical sleep. But he did qualify this assessment by explaining:
“Horses can go for days without holding to this pattern. That makes evolutionary sense since horses were a migratory species. Having to take a nap may have made you someone else’s dinner.”
Two researchers in Germany at the Veterinary Faculty of the Ludwig Maximilian University, in Munich, confirmed that horses do experience these four distinct sleep phases, and each phase is short and frequently interrupted by waking phases.
Researchers everywhere agree that at some stage horses must lie down to go into a deep sleep. Standing sleep will benefit the horse, but it’s only a snooze. Like humans and other animals, horses need to experience slow-wave sleep (SWS) and rapid-eye-movement (REM) deep sleep.
So what does all this mean to a New Zealand horse trainer? The issue seems to be the overall wellness of the horse rather keeping tabs on the sleeping hours.
“I would often go back to the stable at nine or 10 pm and find some would be laying down sleeping and some would be standing, said former leading trainer Jim Gibbs from Matamata this week, “and if you made a little noise it would be the ones standing that would wake or get a little fright or wake.
“The relaxed horses
would be laid-back snoring, and then
you’d get one with a really good
temperament and he might be so relaxed
he might have to be coaxed quietly up in the morning.
“Horses do a lot of travelling – the
greatest thing for some horses is to have a trip away. Sometimes going away for
the first time they might not feed that well, but
the next trip away could be the making them.”
“But when we travelled horses long distances we’d go early and spend a night before the races and then a night afterward.
“Bill Ford used to say that a trip away could make the horse and he might move up two or three grades straight away, but I’m not in favour of doing a five hour trip to the races, as they do to Ruakaka, and then back again in the same day – I think that’s too stressful.
“On a sunny day, horses in a yard or paddock love to lay down and have a sleep. They stretch out and really enjoy the moment – wonderful to see,” Jim enthused. You know yourself that if you can’t sleep you’re in trouble so horses will be the same.”
Taranaki trainer John Wheeler admits: “I don’t know very much about horses sleeping patterns except that young horses, especially two-year-olds after the first couple of gallops can get very physically tired; they’ll be stretched right out in the box sleeping it off. But I haven’t noticed any problems with older horses.
“When I worked for Cummings he was very big on letting horses rest during the day and not disturbing them just like Chris Waller is now. Horses need space and can have too much human intervention. Bart didn’t like the staff spending too much time on the grooming – he used to say ‘grooming only wins owners, it never wins races.’ “
“I haven’t detected horses being short of sleep, but I can tell you that horses definitely dream,” he added.
Pukekohe trainer Nigel Tiley says he’s aware of his team’s sleeping habits by checking the boxes in quiet times:
“I check the horses daily for behavior and can tell which horses have been laying down to sleep, says Tiley. “Some stand up and sleep, and you always know when your babies are growing because they lay flat out, stretched right out in the box.
“Our staff depart the stable at 10 am and don’t return until 3 pm, and it’s between those times they are resting. If I had cameras on them, I would have the definitive answer but doing the rounds and knowing your horses will alert you to any change of behavior.
“On a trip to Trentham, we’ll load up at 2 am, stop briefly at Wairakei and then we’ll carry on down and get to Trentham just after lunch. We put them into yards, and then we take them for a pick about 5 pm. So far I have never detected that some horses are more affected by the trip than others.”
In conducting his research in the USA, Dr. Bertone challenged horsemen by asking if they knew how much sleep their horses were getting. The question was no doubt, purely rhetorical and one that didn’t draw a relevant response.
If the same question were asked of all trainers in New Zealand, it would likely also draw a blank. Perhaps we should talk to the wives to glean the material for a follow-up story – “Is Your Trainer Getting Enough Sleep.”
by Brian de Lore