Top 5 Signs of Horse Heatstroke

It is hot (or getting hot) in many parts of the world, and riders are out and about enjoying riding their horse.  Whether riding in shows and competitions, enjoying trail rides, taking lessons in an arena, sorting cows, racing at the track or feeling the thrill of a fast canter along the beach, there is no better time to own a horse!

However, high temperatures can pose a serious, sometimes deadly, risk to your horse. Heatstroke aka overheating or heat stress can occur not just from riding, but also from trailering, being in a hot stuffy stall or even being out in the field with the sun blaring down and no shade.  I believe every rider should know the 5 key signs of heatstroke and what to do if this occurs. Equally important, every rider should know how to prevent it!

What is Heatstroke?  What Can It Cause?
Heatstroke is not a stroke in the conventional sense of how you may think about a human having a stroke.  Rather, it is the horse’s inability to cool him or herself down and get rid of excess heat.  Like humans, horses have a natural cooling process in their body.  This involves sweating and purging heat from nasal breathing/respiration (much like a dog may pant).  But, in some cases of exposure to high heat levels, the horse may be unable to cool themselves.  To try and compensate, the horse may sweat excessively, increase its respiration rate, and even redirect blood flow closer to the skin to aid in the cooling process.  However, excess sweating can cause dehydration and loss of electrolytes, and redistributing blood flow closer to the skin can cause the brain and other organs to receive less oxygen.  Left untreated, this can cause colic, seizures, severe muscle cramps and even death.

What Are the Signs of Heatstroke?
Here are 5 key signs.

1. Elevated respiration rate
2. Elevated body temperature
3. Excessive sweating, or the absence of sweating
4. Elevated heart rate
5. Stumbling, muscle cramping and/or lethargy

As you can see, some of the signs involve not only observation but taking your horse’s vitals.  If you don’t know how to do this, the time to learn is not in an emergency situation.  Learning to take your horse’s vitals is also important so you know their baseline values and can compare them to the situation at hand.  For information about taking your horse’s vitals and a free downloadable vitals chart, visit my Knowing Your Horse's Vital Signs blog post.

What are the Treatments for Heatstroke?
The best treatment is actually not a treatment.  It is prevention.  Here are some prevention tips.

• Don’t over exercise or overwork your horse in high heat situations (or any situation).  Heat stroke can occur even if the temperatures are not hot.
• Always thoroughly cool your horse down by walking after exercising.
• Make sure your horse has access to plenty of clean water to drink.
• Be sure your horse has access to shade.
• If the horse is in a barn or stall, be sure the area is well ventilated.  Use fans if necessary.
• Replenish salts/electrolytes if your horse is sweating excessively
• Bathe or hose your horse off with cool water paying close attention to the large blood vessels inside the legs, on the belly and the neck.
• Make sure your horse has access to adequate hay which provides fuel and energy to regulate their body temperature and cooling processes

Here are the key treatments for a horse with heatstroke. 

• Stop riding immediately.
• If you believe it is serious, always contact your veterinarian immediately.  Providing your vet with your horse’s vital signs will help him or her assess the situation on the phone.  IV electrolytes may be needed among other veterinary care modalities.
• Seek shade, and fan your horse on all sides if possible.
• As noted above, douse your horse with cold water/cold hose your horse down, paying special attention to the large blood vessels inside the legs, and on the neck and belly.  You can even mix the water with ice cubes as was done at the Olympic games. A 50/50 water and alcohol mixture is also good.
• Offer your horse as much water as they will drink.
• Continue to monitor their vitals to see if they improve

The Bottom Line…. An ounce of prevention is worth a pound of cure. Be prudent about the duration and intensity of your ride so you can enjoy the whole summer with your horse and many more seasons together!

​Have you ever dealt with a horse that suffered from heatstroke?  What happened?  Share your story on our Stretch Your Horse Facebook page.