How well can horses withstand heat?

How well can horses really withstand warm temperatures? In the worst case overheating leads to death, but in the worst case everything actually leads to death. So how badly do I really need to worry? What can I do with my horse in the heat? What do I have to watch out for? And how can I help my horse tolerate the heat better?

Author: Marie-Theres Conen, Karolina Kardel, Veronika Conen

In principle, horses have no problems with summer temperatures. Their comfort temperature ranges from plus 25 to minus 15 degrees. Their metabolism functions best at 5 degrees. Within their comfort temperature, they do not yet have to work hard against overheating or hypothermia.

Outside their comfort temperature, horses can access their thermoregulation abilities. You can read about how they warm themselves here: When does my horse feel cold?

This is how horses cool themselves:

a) Sweating

When sweat evaporates, evaporative cooling occurs and serves to cool the organism. About 60% of the cooling capacity takes place in this way.

A horse weighing 500 kilos with a body surface of 5 square metres needs many sweat glands to be refreshed by sweating. In addition to sebaceous glands, there are 400 to 500 tubular sweat glands in one square centimetre of skin. Up to 30 litres of sweat can be produced per hour.

Most sweat glands are located on the neck, chest, shoulders, flank and sides of the abdomen. They are also densely distributed on the forehead and throat.

As with cold, the humidity of the air is again a decisive factor. If it is humid, the sweat can evaporate more slowly and there is less cooling. So if the horse stays dry during work in hot weather, it does not mean that he is not sweating! The sweat just evaporates so quickly that you can't see it. So the mechanism works perfectly.

SWEATING IS HEALTHY!

b) Breathing

When exhaling, not only carbon dioxide is exhaled but also heat. The heated breathing air is exchanged by cool fresh air when inhaling. The inhaled air cools down on its way through the long head via the moist mucous membranes. This mechanism covers about 33% of the cooling capacity.

c) Heat Radiation

Release of body heat via the surface. The difference to the outside temperature plays a role here. Low degrees and a brisk "breeze" are helpful. If the receptors register too much heat, the horse has the possibility to cool the body by dilating the arterial vessels.

Animals with a larger body surface can cool down more easily. The smaller the body surface, the less energy they have to expend to keep warm.

d) Heat convection

Heated blood is carried through the veins into the capillaries on the surface, where it is cooled and returned to the interior. This form of cooling works particularly well in breeds with thin skin. 

e) Heat conduction 

The contact of the warm surface of the body with cold matter provides cooling. For example, with ice bandages and washing off with cold water.After showering off, it is important to remove the heated water with a sweat knife. If necessary, repeat this procedure several times.

A practical side effect: without the sweat in the coat, the horses are less attractive to pesky insects afterwards.

All cooling mechanisms except breathing are much more effective in the short summer coat than in the long winter coat!

NMore on sweating and heat regulation in horses.

So a healthy horse doesn't have too bad problems in warm weather. It is more strenuous for the animals' metabolism than cold, but with a little care everything is doable.

Of course, care should always be taken to ensure that the horses have a shady shelter and enough water to drink. You should also keep an eye on your youngest and oldest horses, as these horses have problems with thermoregulation more quickly.

How can I tell if my horse is too warm?

Let's take a look at the medical values of a healthy horse. Here are some of the commonly monitored values:
Body temperature: a horse's normal body temperature is between 37.2°C and 38.3°C. 
Pulse: A horse's normal pulse at rest is between 28 and 44 beats per minute. After intense exertion, the pulse may increase temporarily.
Respiration: The normal respiratory rate of a horse is about 8 to 16 breaths per minute.

Signs of overheating may include:

• Even before riding: The horse's normal values are greatly altered. Higher body temperature, breathing rate or (or too low) plus. Excessive sweating immediately after being brought out of the paddock.

• Horses with poor circulation may have pale or grey mucous membranes.Horse appears lethargic and disinterested, has altered temperament and does not want to participate.

Acute, call the vet quickly:

• Dizziness or balance problems. Horse is wobbly or unsteady on its feet.
• The horse shows colic symptoms: horse behaves restlessly, wanders around constantly, stamps its front hooves or lies down frequently. Poor digestion, lack of bowel sounds.

These symptoms usually occur in combination:If your horse shows these symptoms, we recommend that you call a veterinarian to determine the exact cause and take appropriate measures to stabilise the horse.

Up to what temperature can I ride my horse?

We would give this rule of thumb: If it is too warm for you to put on long breeches, then it is too warm for your horse to be ridden.

If the weather forecast says over 30 degrees, you should reduce the load on the horse. Logically, it is recommended to avoid riding during the hottest part of the day and instead train in the cooler morning or evening hours.

If you know your horse well, you can offer him as much exercise as he wants. If your horse is fit and motivated, there is nothing to be said against a diligent ride in the shady forest, even if it is 30 degrees.

The same goes for lunging. If it is warm and your horse feels like moving around, then you can allow him to do so. However, if it is very unmotivated and sluggish, contrary to its normal temperament, do not force it to exert itself excessively.

What should I look for in my equipment when I go riding in the summer?

Make sure you use a breathable saddle padto protect your horse from heat build-up under the saddle. Of course, a wool saddle pad is best. Heat build-up can cause tension and, in the worst case, tissue damage.

A Saddle Pad made of wool is beneficial for horses in summer for several reasons:

• Breathability: a saddle pad made of wool allows air to circulate between the horse's back and the saddle, helping to prevent overheating and moisture build-up.
• Moisture management: If the horse sweats while riding, the wool saddle blanket absorbs the sweat and wicks it away from the horse's skin for a more comfortable riding experience.
• Padding and pressure distribution: Wool has a natural elasticity that allows it to reduce pressure points on the skin. By distributing the pressure over a larger area, the blood vessels are not constricted, which promotes blood circulation.
• Temperature regulation: Wool helps to balance the horse's body temperature. By maintaining an optimal body temperature, the blood vessels can remain relaxed and blood circulation is improved.
• Fit of the pad: The saddle blanket chambers well, allowing air to circulate in the panel channel and heat exchange to take place.
• Sweet Itch friendly: Wool is kind to the skin and antibacterial. This reduces friction and chafing.
• Gel, neoprene and other synthetic pads cause heat build-up as heat cannot rise through the material. Heat in combination with pressure can very quickly damage tissue.

Why don't you take a look at the sweat pattern after riding in the summer?

The sweat pattern of wet and dry areas gives us information about the fit of the saddle. A perfect picture would be a perfectly evenly moist horse's back with a dry patch along the spine. 

When riding, the weight of the saddle and rider exert pressure on the saddle area. Too much pressure inhibits the function of the sweat glands. The tissue is undersupplied, so that no natural sweat production is possible. Overheating is also possible more quickly.

A dry spot caused by pressure does not damage the skin or tissue areas immediately, but it prevents good blood circulation to the tissue. Because of this, consequential damage such as muscle tension, atrophy or even saddle pressure can occur. 

Training Excercises for your horse at temperatures above 30 degrees

The temperature limits for riding a horse can vary depending on individual tolerance, the horse's fitness and the level of exertion. It is important to consider your horse's needs and pay attention to his body language.

However, it is not good for the metabolism to leave the horse standing all summer. From 35 degrees, or if you have no possibility to move your horse in the morning or in the evening, the pony can do a bit of free exercise without hesitation. But there are also other exercises you can do with your horse in summer. You can find detailed instructions here.

• Exercises with target stick: You hold the target in front of your horse's nose and as soon as it touches the target with its nose, it gives a click and a biscuit. In this way you can gradually learn more complex movements.
• Retrieving objects:The aim of this exercise is for your horse to pick up the object with its mouth and give it to you. The procedure for this could be that you click immediately when your horse picks up the object in its mouth and then extend it until it gives you the object.
• Unstable surfaces: Balance Pads/Mat: When standing on unstable surfaces, your horse must constantly balance himself. This activates the proprioceptors, improves balance and also strengthens the important deep muscles that are responsible for support and stability.
• Creative lead training: From the left, from the right, walking in front of the horse, leading with distance, leading with neck ring, leading freely and without equipment.
• Lead course:Poles in zigzag, different heights, serpentine lines/slalom with cones, a tarpaulin, alleys of different widths, unstable surfaces, stopping with pinpoint accuracy.
• Classical handwork and long reins or double lunge: All classical track figures or simply on the straight with transitions. Later, lateral gaits can be added and combined with the track figures.
• Isometric exercises:Slowly apply pressure with the hands in the shoulder or flank area. It should not take a step to the side, but react with counter-pressure. Strengthens the core muscles.
• Stretching exercises: Have a relaxing effect and promote blood circulation. Stretch the front and hind legs and the neck. The horse should be warmed up for this.
• Loosening massage strokes: Stroke your horse's body with the palms of your hands in the direction of the coat. The rake grip: form a rake with the fingers and pull it over the horse's body. Kneading: e.g. on the arm-head muscle on the lower neck, the upper neck muscles or on the hindquarters.
  

Are there ways to improve the horse's ability to regulate heat?

Yes, with training. The fitter you train your horse in the cool months, the better equipped his metabolism will be for the summer heat. 

Endurance Training is important for the health of all horses. It prevents injuries and overstraining. The primary goal of basic conditioning is to develop the physiological foundations and metabolism so that the horse can withstand all the stresses placed on it with minimal risk of injury.

Effects of good endurance training

• Degradation of fat as an insulating layer.
• Development of the cardiovascular system, resulting in more effective removal of heat via the blood vessels. 
• Expansion of the aerobic system, energy production through fat burning produces less heat, building of muscles, more efficient use of energy and less waste heat.
• Riding at a constant pace promotes deep, regular inhalation and exhalation and thus heat exchange. Breathing volume improves, i.e. the amount of oxygen per breath is increased by exercising breathing technique and breathing muscles.
• Endurance training promotes the formation of additional sweat glands for evaporative cooling.

"But my horse has zero stamina!" If you want to say that now, then you have the most important reason to start his endurance training immediately.

How you can best build up stamina training, you can learn here.

Conclusion: Horses, especially Icelandic horses, can handle heat worse than cold. However, this should not stop you from exercising your horse in summer.

As long as you pay attention to his signs, you won't do anything wrong. And if it really is 36 degrees and it gets even hotter, then stay at home. If your horse has a shady spot and enough to drink, he'll be happy if you don't want anything from him.