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Dehydration in Horses: How to Recognize & Manage Symptoms

Last updated: February 19, 2024

By: Miles HenryFact Checked

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Did you know that an average-sized horse can drink 15 gallons of water per day? Hydration is crucial for horses, affecting everything from performance to health. Drawing from my 25 years of experience in the horse racing industry and as a horse owner, I’ve seen firsthand the impact of proper hydration on a horse’s well-being and performance.

This article aims to empower fellow horse owners with the knowledge to identify and address dehydration in their horses, ensuring their equine companions remain healthy and vibrant.

picture of a vet checking a horses gums. This is one way to recognize dehydration in horses.
Checking a horse’s gums for signs of dehydration.

Is Your Horse Dehydrated? Identifying the Signs and Action Tips

Dehydration in horses can be subtle but has serious implications for their health. Recognizing the early signs is crucial for prompt intervention. Here are clear, observable indicators that your horse might be dehydrated:

  • Lethargy: A noticeable lack of energy or enthusiasm for regular activities.
  • Dry Gums: Healthy gums should be slick and moist; dryness indicates dehydration.
  • Increased Capillary Refill Time: Press on your horse’s gum and release. The color should return within 2 seconds. A delay suggests dehydration.
  • Sunken Eyes: An indication of severe dehydration, showing a noticeable recession in the horse’s eye sockets.
  • Reduced Skin Elasticity: Perform the skin tent test by gently pinching the skin on the neck or shoulder. If it doesn’t snap back quickly, your horse could be dehydrated.
  • Dark Urine: Dark, concentrated urine is a sign of dehydration, indicating that your horse is not expelling as much fluid as it should.
  • High Heart Rate: An elevated heart rate that does not return to normal after rest can also be an indicator of dehydration.

Immediate Actions for Treatment

If you suspect your horse is overheating while riding a long distance, it’s best to dismount, give your horse water, and take a break. Unsaddle the horse, remove all tack, and bathe it with cold water to help cool it down.

Scrape excessive water from your animal and repeat running water over its entire body; water left on the horse becomes warm and insulates the heat, so it’s crucial to remove it. Once you’ve finished washing, place the horse in a well-shaded area and, if possible, use a fan to help cool the animal down. Always offer your horse fresh, clean water during the cool-down period.

Picture of my horse grazing.
We give our horses a bath immediately after a workout.

Professional Treatment: IV Treatment

For horses experiencing excessive fluid loss due to dehydration, veterinarians may use saline solutions and other fluids to restore blood volume. Typical intravenous solutions include normal saline with added potassium and possibly calcium.

In some cases, hypertonic saline solutions, along with plasma or blood, are used to restore fluid volume and balance in the animal’s bloodstream. Some severely dehydrated horses may require up to 80 liters of fluid over a 12-hour period to rehydrate.

Understanding Dehydration Risks

Horses drink approximately a gallon of water per 100 pounds of body weight, or about 10 gallons a day for a normal-sized animal. The amount of water intake varies based on climate, fitness level, and exertion.

A horse starts showing signs of dehydration within two days of being deprived of water. Horses deprived of water for three to four days can develop severe physical problems, with organs beginning to shut down and irreversible damage to tissues likely.

Early detection of these signs can prevent complications such as colic, renal failure, and decreased performance. Untreated dehydration not only affects your horse’s immediate well-being but can have long-term health consequences. Always ensure your horse has access to fresh water, and consult a veterinarian if you suspect dehydration.

Picture of horses in a pasture with a pond.
The pond in this pasture allows horses access to water 24 hours a day.

Quick Dehydration Tests You Can Do

Monitoring your horse’s hydration status is essential for their health and well-being. Here are two simple yet effective tests you can perform to quickly assess if your horse might be dehydrated:

Skin Tent Test:

  • Gently pinch and lift the skin on your horse’s neck or shoulder, then release it. In a well-hydrated horse, the skin should snap back into place almost immediately. If the skin remains tented for a few seconds, it indicates dehydration. This test is quick and easy, giving you an immediate sense of your horse’s hydration level.

Checking for Dry Mucous Membranes:

  • Examine the gums above your horse’s teeth. They should be moist and slick. Dry, sticky, or tacky gums are a sign of dehydration. This test is particularly useful because it provides a direct indicator of fluid loss. Additionally, you can check the capillary refill time by pressing on the gums to create a white spot. Count how long it takes for the color to return; more than 2 seconds can indicate dehydration.

These tests are straightforward and can be done regularly to ensure your horse remains hydrated, especially during hot weather, after exercise, or if your horse is ill. If you suspect your horse is dehydrated, provide fresh water immediately and consult a veterinarian for further advice and treatment.

Picture of horses in a pond.
Herd of horses getting in the water on a hot day.

Causes and Prevention of Dehydration in Horses

Dehydration in horses can stem from various factors, often interrelated, affecting their health significantly. Understanding these causes is the first step in prevention.

Common Causes of Dehydration:

  • Heat: High temperatures increase sweat rates, leading to significant fluid loss.
  • Exercise: Intense or prolonged physical activity without adequate water intake can quickly lead to dehydration.
  • Illness: Conditions such as diarrhea or any illness causing fever can result in rapid fluid loss.

Proactive Hydration Management

  • Monitor Water Quality and Availability: Ensure your horse has constant access to clean, fresh water. Regularly clean water troughs and buckets to prevent algae growth and contamination, which can deter horses from drinking.
  • Offer Electrolytes During High Stress: In hot climates, during intense training, or when your horse sweats excessively, supplementing with electrolytes can help maintain fluid balance. Consult with a veterinarian to choose an appropriate electrolyte supplement.
  • Adjust Diet for Hydration: Incorporate high-moisture feeds, such as soaked beet pulp or hay cubes, to increase water intake, especially for horses that may be reluctant to drink enough water.
  • Provide Access to Salt: A salt block or loose salt encourages drinking by helping to maintain electrolyte balance. Ensure salt is always available, especially during warmer months or for working horses.
  • Acclimate to Weather Changes: Gradually acclimate your horse to changes in weather, especially heat, to prevent heat stress and encourage normal drinking behavior.
  • Familiarize Water During Travel: Horses may be reluctant to drink unfamiliar water when traveling. You can encourage drinking by adding a familiar flavor to the water at home and then using the same flavoring on the road.

Regular Monitoring and Adjustment

  • Observe Drinking Habits: Regularly observe your horse’s drinking habits and be alert to any changes, as this can be an early sign of health issues or dehydration.
  • Adjust Workloads According to Weather: On hot days, reduce the intensity of workouts and provide ample opportunities for your horse to drink during and after exercise.
  • Plan for Recovery: After strenuous exercise or during hot weather, ensure your horse has immediate access to water. Allow them to drink small amounts frequently to rehydrate effectively.
picture of a horses eyes that may be be showing the early signs it dehydrated,

When to Seek Veterinary Help for Dehydration in Horses

While many cases of mild dehydration can be managed with increased water intake and careful monitoring, certain situations warrant immediate veterinary attention. Recognizing the signs of severe dehydration and understanding when to call a veterinarian are crucial for your horse’s health. Here are key indicators that professional intervention is needed:

  • Persistent Signs: If signs of dehydration, such as lethargy, dry gums, and prolonged capillary refill time, persist despite your efforts to rehydrate your horse, it’s time to call a vet.
  • Refusal to Drink: A horse that refuses to drink water for an extended period, especially in hot weather or after exercise, may be at risk of severe dehydration or other underlying health issues.
  • Severe Lethargy or Weakness: Extreme weakness or lethargy, where the horse is unwilling or unable to stand, indicates a critical situation requiring immediate veterinary care.
  • Rapid Pulse and Breathing: An elevated heart rate and rapid breathing that do not normalize with rest can be signs of severe dehydration and distress.
  • Dark or Discolored Urine: Dark, concentrated urine or a significant decrease in urination suggests that the horse is not consuming enough water, leading to potential kidney stress or failure.
  • Signs of Colic: Dehydration can lead to impaction colic, characterized by abdominal pain, restlessness, and attempts to lie down frequently. Colic is a veterinary emergency.
  • Other Illness Symptoms: Symptoms like diarrhea, vomiting (in the case of nasogastric tube reflux), or fever alongside dehydration signs significantly increase the risk of complications and require veterinary intervention.

What to Expect from Veterinary Care:

A veterinarian will assess your horse’s hydration status, possibly through blood tests and a physical examination, to determine the severity of dehydration. Treatment may include oral electrolyte solutions or, in severe cases, intravenous fluids to rapidly rehydrate your horse. The vet can also identify and treat any underlying causes of dehydration.

Preventing Emergencies:

Regular monitoring of your horse’s hydration status, especially during hot weather or periods of increased activity, can prevent severe dehydration. Familiarize yourself with the signs of dehydration and establish a proactive hydration management plan to keep your horse healthy and hydrated.

Remember, timely veterinary intervention can be the difference between a quick recovery and a potentially life-threatening situation. When in doubt, always err on the side of caution and consult your veterinarian.

two.year .old

Conclusion: Ensuring Your Horse’s Hydration

We’ve explored the critical importance of recognizing and addressing dehydration in horses. From identifying the telltale signs of dehydration, such as lethargy and dry gums, to conducting simple tests like the skin tent and mucous membrane checks, I’ve provided you with the tools to ensure your horse remains hydrated.

I also discussed the common causes of dehydration, including heat, exercise, and illness, and offered practical tips for prevention, emphasizing the necessity of constant access to clean water and proper management practices.

Severe dehydration requires immediate veterinary intervention, and we’ve outlined when it’s crucial to seek professional help. Your horse’s health and well-being are paramount, and understanding the signs of dehydration is key to preventing serious health issues.

Prioritize Your Horse’s Hydration

As horse owners, it’s our responsibility to ensure the well-being of our equine companions. Hydration plays a fundamental role in a horse’s overall health, affecting everything from their performance to their ability to recover from exercise and stress.

By incorporating regular hydration checks into your daily care routine and being vigilant for signs of dehydration, you can help maintain your horse’s health and vitality.

Additional Resources

For further information and resources on horse care and hydration, consider visiting authoritative sites such as:

  • Oral Electrolyte and Water Supplementation in Horses
    This comprehensive review by Michael Ivan Lindinger on PubMed Central discusses the critical role of electrolytes and water in maintaining hydration in horses, especially under conditions of heat stress and prolonged sweating.
  • Optimizing Water Intake – Oklahoma State University
    Kris Hiney from Oklahoma State University provides insights into ensuring adequate water intake by horses. It emphasizes the importance of monitoring water intake, especially during travel or when introducing horses to new environments, to prevent dehydration.
  • American Association of Equine Practitioners (AAEP) – Provides information on equine health.

Below is a helpful YouTube video that explains how to check your horse for dehydration.

YouTube video

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