Study: 20% of horses are suffering from lack of sleep

 Is your horse getting enough sleep?

New research into the lying patterns of horses has uncovered that 20% of horses are only lying down for less than one hour in a 24-hour period.  More worryingly, 9% of horses only lie down for less than 30 minutes, putting them at significant risk of collapse and injury.

Researcher Juan de Benedetti, who is reading Data Science and Analytics at Brunel University, studied the behaviour of 43 healthy horses that were being monitored using the Trackener device in 2019. Using motion sensors, Trackener automatically detects if the horse is standing, in sternal or lateral recumbency (lying upright or flat on side).

The majority of the horses being monitored were leisure horses with a few being performance horses, living most of the time in a stable and turned out in a field or paddock at least for a few hours every day. This study sheds light on the fact that a lot of horses are not getting enough sleep even in their usual environment.

According to vets and equine researchers, horse owners should know the duration their horse has spent lying down in order to avoid the risk of collapse, especially in light of the 2019 study by the Ludwig-Maximilian-University of Munich, Germany that showed a correlation between the time the horse spent lying down and the risk of collapse. In that ground-breaking study, over 90% of the horses were injured after collapsing with 20% having to be put down afterwards.

A study from 2008 by the American Association of Equine Practitioners showed that, in order get quality REM-sleep (also called recumbent sleep), which is vital for the horse’s well-being and performance, horses need to be lying down for at least 30 minutes per day. Hence the importance of knowing how much time the horse has been lying down.

As researcher Christine Fuchs leading the 2019 study was saying: “Horse owners need to be aware that the sleeping behaviour of horses is an important thing to consider. It is important to recognize the symptoms [of collapse] as soon as possible but prevention is essential.”

Mr Benedetti's study involved analysing 560 days of data from 43 healthy horses wearing a Trackener device over a minimum of 48 hours. This is the first study to analyse the lying patterns of horses over several days. He found that 9 horses out of the sample (20%) were lying down for less than an hour in each 24 hour period and 4 were lying for less than 30 minutes (9%). The horses lie down the most between midnight and 3am (35 minutes on average during this 3-hour period), and between 9pm and midnight lie down for 25 minutes on average.


Dr Michael Hewetson, vet and senior lecturer in equine internal medicine at the Royal Veterinary College commented "A normal horse requires a minimum of one hour’s REM (paradoxical) sleep per day which requires the horse to lie down. If a horse lies down for less than that, they have an increased risk of sleep deprivation which can lead to injury if they collapse. At the hospital, we see cases of sleep deprived horses due to either an underlying painful condition or because the horse is insecure in its environment. These findings show that horse owners should be aware of their horse’s sleep patterns and take appropriate action should their horse appear to be sleep-deprived. The Trackener technology is an easy to use and cost-effective tool to monitor a horse's behaviour night and day."

It is also important to understand if some deviations of a horse’s sleeping patterns can be explained by causes that are also normal. For example, it has been noted that horses lie down more on deep litter bedding than at grass (McGreevy, 2004) and spend more time lying down when exercised more (Caanitz et al., 1991). Furthermore, horses tend to lie down less with cold weather and hot weather due to heat loss when lying on a cold floor and the need for tail-swishing to combat flies during the summer (Blocksdorf, 2019 and Boy and Duncan, 1979). Should there be no easy explanation for a deviation in the horse’s ‘normal’ sleeping pattern, there may then be cause for concern and a need for the owner to be notified so that the first signs of a problem can be picked up as early as possible.