Is My Horse Dehydrated? 10 Clear Signs of Equine Dehydration

Last Updated on February 23, 2022 by Allison Price

My granddaughter and I approached my horse. He was usually happy to approach us, but he remained still in his paddock. We knew something was wrong. I thought, “Could he be dehydrated?”

Horses who are severely dehydrated due to a lack of water or minerals are called “dehydrated”. Dehydration can be manifested as lethargy and red mucous membranes. Skin tenting, loss appetite, excessive sweating or none sweating, high heart beat, dark urine, dizziness, fever, and other symptoms.

Equine dehydration can be dangerous and should be treated immediately. While some signs of equine hypohydration may be subtle, others can be easily identified.

Horses can become dehydrated if they lose too many fluids.

Horses become dehydrated when they lose more fluid that they consume. This causes the horse to not have enough water for proper function. Horses become dehydrated if the fluid isn’t replenished.

Animal dehydration is no different from that in humans. Horses are particularly at risk. Horses are most likely to become dehydrated from overexertion at high temperatures.

Horses can dissipate heat very efficiently through sweating and respiration. This is great for cooling them. However, they also reduce the amount of electrolytes and water their organs require.

Horses can lose up to 5% during a race of one mile. Temperature, humidity and race length all influence the amount of fluid and Electrolyte lost.

Trainers stress proper hydration before and during races to reduce the risk of horses becoming dehydrated from their extreme fluid loss.

Horses can also become dehydrated due to severe diarrhea, fever, a lack of clean water, medication, or hot climates. Mild dehydration can usually be reversed with water and electrolytes.

Horses showing signs of dehydration

Horses can show signs of dehydration in many ways. If your horse seems dehydrated, you can move him to a shaded area, wash him, and then let him drink. Contact the veterinarian.

Is My Horse Dehydrated

Here are some signs that your horse is suffering from dehydration.

Red mucous membranes

A horse should have pink gums if it is well-hydrated and healthy. Dehydration, blood loss, anemia or infection could all lead to deviations. Horses suffering from dehydration are often characterized by pale mucous membranes.

It is easy to assess a horse’s health by looking at its mucous membranes. These tissues line the body cavities such as the gums or inside the nostrils. These membranes secrete mucus that keeps them moist and protected, and they are also supplied with blood.

A capillary refill test is a quick way to check the gums of your horse. Press on the horse’s gums, and then release the pressure. The membranes will “pink up” in a matter of seconds.

Your horse may be suffering from dehydration if it takes more than two seconds for the pressure to return to its pink form. You should also check the amount of saliva that he has on his gums. Dry mouth can also indicate that a horse isn’t properly hydrated.

A horse’s gums will show signs of dehydration by a reddening tissue at the tooth junction and paling of the rest. As dehydration progresses, the mucous membranes begin to pale and then turn bluish-purplish.

These colors are associated with longer capillary refill times. Sometimes horses’ gums turn deep red. If animals’ hydration drops to this level, it is called septic shock or endotoxin.


Horse lethargy can indicate dehydration and early signs of equine disease. Lethargy and diarrhea are early signs of Swamp Fever and Potomac Horse Fever.

Your horse may become more quiet after strenuous exercise than usual. This could be an early sign of dehydration. You can take preventative action and give your horse water and electrolytes immediately. It is easier to stop dehydration in this stage than it is to fight it later.

Untreated disease can cause shock, permanent lameness and even death. The likelihood of recovery is greatly increased if the disease is treated promptly.

All of us have had a lazy horse. Horses are usually alert and lively.

A sluggish horse will have a hanging lip, a lowered head, not eating and standing in the corner without any interest in what is around them.

Skin tenting

Horsemen use a “skin tent test” to quickly check the horses’ hydration. Normal skin tissue is elastic and contains a high percentage water content.

Dehydrated horses’ skin tissues become “sticky” and can move slower. They are also less likely to recover to their normal state after being pinched. The “skin tent” test is performed by squeezing a horse’s skin on its shoulder. Pull it upwards to form a tent-like shape, then release it.

Normal horse skin should be flattened within one second of being let go. It is a sign of severe dehydration if the skin takes longer to recover to normal. Horse skin that takes more than four seconds to heal should be treated immediately.

The standard tent test doesn’t measure hydration, but it is a quick tool for assessing a horse. This test is most reliable when it’s used by owners who know their horse’s reaction to the test in normal conditions.

Sweating/Not sweating

Horses can lose a lot fluid from exercise. If the fluid isn’t replaced, the animal could become dehydrated. The body produces heat by sweating. As the skin temperature rises, blood vessels dilate and blood flow increases.

The sweat production and fluid loss is increased in hot, humid environments. For proper functioning of the organs such as the heart and muscles, brain, kidneys, and liver, it is crucial that competitive horses work for long periods.

The sweat glands increase the production of moisture on the skin’s surface. During activity, the adrenal glands aid in this process. Although the process is complex, this is an overview.

When horses are stressed, sweat is released to regulate their body temperature. Extreme sweating can cause severe dehydration.

Anhidrosis can be caused by chronic dehydration in horses. Anhidrosis refers to the inability of horses and humans to sweat. The condition can develop over time and can be caused either by genetics, diet or chronic dehydration.

Anhidrosis is a condition in which the sweat glands stop working in horses. This condition can be difficult to reverse and often is permanent. It is possible to prevent the disease from happening by keeping your horse hydrated.

Dry, dull eyes

The horse’s eyes are a sign of its general level of hydration. Dry, dull-looking eyes can indicate a horse is dehydrated. A mucous membrane is found in the conjunctival sac.

It secretes viscous pus that keeps the eyes protected and moist under normal conditions. Horses can become dry and dull-looking if their eyes are dehydrated. The eyes of a dehydrated horse may appear as if they have been sunken into its skull.

Appetite loss

Horses love to eat, so if your horse is not interested in his food, it could be a physical problem. Dehydration is one reason horses stop eating.

A horse’s inability to eat due to dehydration could be due to its general feeling sick. The lack of adequate bodily fluids or electrolytes could cause colic, which is an intestinal condition that causes pain.

High heart rate

Horses often show rapid heart rates when they become dehydrated or lack electrolytes. Normal horses are in good health and have a resting heart beat of between 36-42 beats each minute.

Because there are many acceptable horse heart rates, horse owners need to have an idea of what their horse’s resting heart rate is. One horse’s normal heart rate can be very different from another horse’s.

Dehydration could indicate a high resting heart rate of more than 60. Endurance racehorses who become dehydrated during a race have incredibly high heart rates.

High heart rate can be an indicator of fluid depletion. This can easily be reversed by adding water and electrolytes.


Fever is often associated with an infection, but it can also be a sign that the horse is dehydrated. Fever-like symptoms can occur when a horse is unable to control its body due to a lack of fluid.

The average temperature of horses is between 98 and 101 degrees. Their temperature can fluctuate throughout the day. Horses in warmer climates have a higher temperature in the afternoon than they do in the morning.

Fever can be either a sign of dehydration, or it could be the cause. Horses suffering from an infection may sweat too much and dehydrate if they don’t replenish their fluids.

A rectal thermometer can be used to check the temperature of your horse. It’s recommended that you do this at least once per month in order to establish a baseline temperature for all horses.

Dark urine

Healthy horses have a yellowish or straw-colored urine. It might appear cloudy, foamy, or a little darker than the others. It can turn brown if it is not healthy. This is usually due to dehydration.

Horses’ hydration levels can be determined by their urine color. Clear urine is a sign that the horse is well-hydrated, while dark urine indicates dehydration.

Dehydration causes a horse to lose water. Their kidneys begin to retain water. Their urine is less concentrated and darker because it contains less water.

As an indicator of hydration, you can also examine the moisture content of horse’s feces. The water content in animal feces should be at least half. Check your horse’s feces to see if there is water.

Dizziness or disorientation

Maintaining proper blood flow is possible only if the body fluids are in the right amounts. Horses that are severely dehydrated experience a decrease in blood volume and blood pressure, as well as a lack of oxygen to their brains. This can lead to dizziness or disorientation.

How to determine if your horse is dehydrated

A complete blood chemistry analysis is the best way to tell if your horse has lost its water.

Sometimes, animals that are dehydrated will not drink. It is important to prevent dehydration and to increase water intake during exercise and hot weather.

Treatments for dehydration

Horse riding treatment

If your horse seems to be overheating, you can dismount the horse and give it water. You can untack the horse, remove all tack, and then bathe it in cold water.

It is also a good idea not to give your horse too much water. Then, run water again over the entire animal. The horse will heat up if water is left on it.

After washing the horse, place it in a shaded area. If possible, you can use a fan or a fan to cool it. During the cool-down, make sure to give your horse plenty of water.

IV Treatment

Horses with excessive fluid loss from dehydration can be in danger of having low blood volume. To restore blood volume, veterinarians use saline solutions or other fluids.

You can use normal saline, with some potassium or calcium added. To restore fluid volume, a veterinarian might use hypertonic solutions with blood or plasma.

Hypertonic solutions can be used to restore water/salt balance in the animal’s bloodstream. Horses that are severely dehydrated may need up to 80 liters (over 12 hours) of fluid to rehydrate.

How long does horses take to become dehydrated?

Horses consume approximately one gallon of water for every 100 pounds of bodyweight, or around 10 gallons per day for an average-sized animal. It is dependent on the animal’s climate, fitness level and how much it is worked that its water intake will vary.

It all depends on fitness, climate, exertion, and other factors. Horses can become dehydrated for a short time due to lack of water. A horse will usually show signs of dehydration two days after being without water.

Horses that are starved for more than three to four days may develop serious physical problems. Organs can become dysfunctional and tissues will suffer irreversible damage.

Preventing dehydration

Horses lose minerals like potassium, sodium, and chloride when they sweat. This is essential for their bodily functions. These electrolytes require replenishment. In many cases horses don’t have enough feed or hay to replace the lost minerals, so electrolyte supplementation is required.

Salt supplementation is necessary to ensure horses get enough water. Horses will drink more water if they have salt; horses who don’t have enough salt in their system lose the desire for drinking.

These are just a few more things you can do for your horse to stay hydrated.

  • You can access a salt block or give a daily salt addition of 1 tablespoon for every 500 pounds.
  • Provide an electrolyte solution for your horse if he sweats too much. A good electrolyte supplement should contain at least 12g of chloride, 6g of sodium and 4g of potassium.
  • Shade is important for horses. If you have to keep them in stalls, ensure that they are well ventilated.
  • To provide extra hydration for horses that require it, we feed crimped oatmeal soaked in water. We also add our supplements to this feeding.

These simple steps will help keep you from becoming dehydrated.

The final word on Equine dehydration

Extreme dehydration can cause severe health consequences, and even death. Horses may require intravenous fluids or other treatments to protect their organs.

If you notice signs of dehydration in horses, cool them down and give them fluids immediately. You should ensure your horse is well hydrated before you start working with him.

Dehydration can cause colic, laminitis and multi-organ failure.

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!