Can Racehorses Overheat?

graphic horse standing in the sunHorse racing is an extremely arduous process at the best of times, asking the horse to run to the best of their abilities and putting them through a true cardiovascular workout. As a result, it is not uncommon for horse to see their core temperature raise to extremely high levels, which can cause them to overheat. There are numerous things that trainers and their workers can do to try to keep a horse’s temperature down and to actively cool them at the end of a race, which can be incredible important to keep them not only healthy, but alive.

Horse differ from animals such as dogs on account of the fact that they do have sweat glands throughout their skin. As a result, their bodies have a natural ability to cool them down that other animals don’t boast. As the sweat changes from a liquid to a gas and evaporates, this acts to cool the horses down. Even so, after long races this alone isn’t enough to stop a horse from over-heating, which is why it can be such a serious problem for race horses. It is also why you’ll often see stable hands throwing buckets of water over horses on hot days.

Horses are more likely to overheat in jump racing compared to flat racing simply due to the longer distances, often heavier ground and the need to jump fences and hurdles.  This is one of the biggest reasons that jump racing takes place over the winter months. It is common to see horses with steam coming off them in long jump races on unseasonably hot days, often with buckets of water thrown over them after a race to prevent overheating.

Horses Can Overheat

cheltenham festival with the sun out
Unseasonably warm day at the Cheltenham Festival

The very nature of horses is such that they can, indeed, overheat. The temperature outside mixed with the internal temperate of the horse during and after a race can mean that they get dangerously hot. Just as with humans who go for a run, a bike ride or lift weights, the heat of a horse builds up during exercise. It needs to be released, which comes in the form of sweating, but sometimes that alone is not enough. When the weather is hot and humid, that can also cause a horse to get too hot, which isn’t something to be dismissive about.

You might notice that your horse’s breathing is more rapid for a longer period of time, which is a sign that they’ve over-heated. It is important to keep a horse’s exercise limited when the weather is too hot, largely because horses already produce large amounts of heat naturally. The digestion of their feed can lead to horses becoming hot, for example, whilst the heat gained from exercise is obvious. If the temperature is cool enough, horses can shunt their blood to their skin to cool it, but if it’s warmer than their body temperature then they can’t.

What It Looks Like When Horses Get Hot

hot horse graphic horse with flames

When horses begin to get too hot, there are numerous things that happen that you can, and should, look out for. For starters, they might sweat profusely, though there are times when they’ll actually sweat less than you’d expect them to. Their skin will be hot to the touch, with this switching to being cold to the touch when their circulation begins to shut down. They might stumble, which can be caused by muscle weakness. Normal adult horses take between eight and 18 breaths a minute, but over-heating horses will breath more rapidly.

The pulse and heart-rate of a horse will normally recover after exercise, but if the horse is over-heating then both are likely to remain high. In Fahrenheit, a horse’s normal body temperature is between 98 to 101 degrees, but this increases to between 102 and 106 degrees when horses overheat. They may also show signs of being dehydrated, which will include sunken eyes, no more urination and skin elasticity, as well as tacky membranes. The temperature may reach as high as 106 to 110 degrees if they’re suffering from heat stroke.

What To Do When A Horse Is Over-Heating

horse being cooled with cold water sprayThe most obvious question is what needs to happen in order to aid the recover of a horse that is over-heating. The first thing to do is to stop the horse from riding, removing both jockey and equipment from it as soon as possible. Getting the horse into shade is also key, whilst it can help to increase the air circulation around the horse. Next, you want to use cool water on the horse, starting with their legs and feet before moving to get the entire body wet. It is important to avoid using cold water, as counter-intuitive as that might seem.

A horse can be allowed to have small sips of water, but it needs to be limited. Try to only allow them to have water in small doses every 15 minutes until the point that a veterinarian says that that can be increases. The important thing is not to overwhelm a horse’s system, which is obviously something that is at risk of happening if you take them from being too hot to too cold too quickly. Bringing their temperature back down slowly and carefully is key to ensuring that they’re stabilised as soon as possible.

Preventing Over-Heating In The First Place

cancelled signUltimately, the best way of dealing with a horse over-heating is to stop it from happening in the first place. The heat index gives a good indication of when it is too hot to race horses, which is why you’ll sometimes hear of racecourses cancelling events. In 2019, for example, a heatwave in the United Kingdom led to Southwell cancelling the last two races of the day in July when temperatures hit 35 degrees centigrade. In Sandown, the temperatures actually got even higher, but racing continued with certain tweaks.

As well as a marquee being erected in the stables and the washing down area, the races were also moved early in the day when it was cooler. Sometimes, though, it is just too hot and the welfare of the horses is put at risk by racing, so the horses are just not allowed to run. Keeping a horse hydrated is key to stopping them from over-heating, as is ensuring that they’ve got enough salt in their system. The horse needs to be cooled before giving it free access to water, but ultimately the key thing is to not allow them to over-exercise if you’re looking to keep them cool.

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