Keeping It Cool This Summer

Dr. Kelly Wentz, Tennessee Equine Hospital
Thompson’s Station, TN
 
The dog days of summer are here.  The combined heat and humidity can be dangerous for both horses and riders.  Heat related illnesses are fatal and must be taken seriously. Hyperthermia or heat stroke can occur if a horse is unable to thermoregulate.  Normal horses in a normal environment are able to control their body temperature, but if a horse is overwhelmed or has an underlying issue that prevents self cooling, trouble can occur.  There are some important factors to know about when dealing with heat and some signs to look for.

• Elevated respiration rate - Normal respiration for a horse is 8-16 breaths per minute.  The first thing owners often notice is an increase in breathing pattern as the horse attempts to cool itself.
• Elevated heart rate - Normal heart rate for a horse is 36-44 beats per minute.  An elevated heart rate is a sign of distress and a way for the body to cool down.
• Elevated rectal temperature - Normal temperature is 99.0 – 101.  Periodic monitoring of rectal temperature is a great way to monitor the cool down process.
• Profuse sweating or not sweating at all.  Horses that are over heated will often sweat significantly more than normal in an attempt to cool the body.  There are also horses that suffer from anhidrosis and are unable to sweat.  These horses are predisposed to overheating as they are unable to cool easily. 
• Lethargy - Horses that are suffering from heat related illness may also lose their appetite, be depressed, become weak, or even collapse.
• Mucous membrane color may be bright red or discolored. As the body attempts to cool, the blood will perfuse to different areas.

If your horse does begin to show signs of hyperthermia there are some things you can do.

• Stop exercise immediately
• Move out of the sun
• Use cool water to rinse the horse, remove excess water with a scraper
• Use a water/alcohol mixture to sponge the horse
• Stand in front of a fan or in a shaded, breezy area
• Offer water
• Call a veterinarian if there is not quick improvement

This summer, work to prevent the emergency! There are some things owners and riders can do to help keep their horses cool.

• Plan to exercise your horse early in the morning or late in the evening, when the temperature is not as hot
• Ride in shaded areas with a breeze
• Maintain a good fitness level with your horse; out of shape horses will be more easily affected
• Offer water and breaks during the ride
• Offer electrolytes in the feed or water to replace those lost in sweat
• Ensure a proper cool down after exercise and cool off procedure
• Know the signs of overheating and know when to call for help

Older horses or horses that are affected with anhidrosis may need to be kept in the shade or by a fan during the hottest part of the day.  If you have any questions about the health or concern with your horse’s ability to thermoregulate, call your veterinarian.  Hyperthermia is a serious issue; work to keep your horse cool this summer!