Flip through the latest issue of Gulf Weekly.
Well, the weather has certainly been the topic of conversation recently. With record-breaking temperatures, it has been scorching, and it is reported that it will get even hotter!
Though many of you have escaped the searing heat, there are those, including our horses, who cannot. What is our body's response to this weather? In nearly all cases we sweat, or in the case of ladies, perspire; which is our body's natural response to the intense heat. The only other mammal with the same natural cooling system is the horse.
During the winter and cooler months of the year it's a familiar sight to see horses dripping with sweat and blowing hard after a workout, the horse now works hard to cool off its body.
But thermo-regulation is more than just sweating, it is the body moving blood from the inner (hot) core to the outer (cooler) surfaces of the skin. Blood flow, panting and sweating all work in conjunction to cool the horse - predominant and most importantly though is the horse's ability to sweat.
But what about the horse that doesn't have this efficient cooling sytem?
The inability to sweat in response to work and or body temperature increase is called anhydrosis. Horses with this affliction are more commonly referred to as dry-coated, or puffers or non-sweaters. Anhydrosis can develop slowly over a period of time or suddenly.
First documented in 1920, when the British began to send their horses to Indonesia, Malaysia, India and other tropical and sub-tropical countries, it appears the problem is most common in thoroughbreds.
As its common name suggests, horses that suffer from anhydrosis stop sweating. This is the most important mechanism for cooling a horse's body, affected horses suffer many of the symptoms of heat stress.
Once internal body temperatures rise to above 40 degrees, heat stroke and other thermal related injuries become an issue. If the horse's body stays at this temperature for more than a short period of time, it will probably die.
The cause of anhydrosis remains a mystery. The horse's sweat glands do not respond to normal hormonal messages that instigate sweating when body temperature increases.
Though the cause has not been determined, recent studies suggest that it is triggered in the hypothalamus gland by the stress of exercise and chronic dehydration under hot, humid conditions. The condition is not prevalent in hot, dry heat, so humidity appears to be a trigger factor.
Horses with anhydrosis are often reported to have sweated very and profusely in the weeks or days prior to the onset, some stop sweating completely, while others continue in a reduced and patchy manner, under the mane, over the chest, and between the hind legs.
Once sweating is impaired other signs become apparent, loss of performance is extremely common, and horses will blow very heavily with widely dilated nostrils for up to an hour or so after exercise as they try to cool their bodies by blowing out the hot air.
Some horses drink large amounts of water, whilst other drink less, horses may try to splash themselves in an effort to cool down.
Andydrosis is a difficult condition to treat and cannot really be 'cured', the only available option is to try and manage the situation; many articles suggest moving the horse to cooler climes! However, as we all know that is not an option likely to happen, so what can we do?
Well, it's usually easier if the horse is in fact fitter as he/she goes into the summer months so keeping your horse fit during the winter can help, but is not a cure.
Providing a cool environment for the horse is essential, and air-conditioned stables are ideal, however, not always available.
Ceiling fans or standing fans - ensuring they are safely placed in the stable - are an option; essential for paddocked horses is the provision of adequate shade and plenty of cool drinking water. A common practice in Bahrain is to keep horses indoors in cool stables during the day and allow them out during the night.
Body clip horses with a thick coat as it retains excess water (when the horse is showered) which in turn retains the heat and interferes with body cooling.
Ideally shower your horse with cooled water and scrape off immediately, and repeat until panting and or blowing is reduced.
A very important factor is to feed a daily electrolyte supplement, which replaces lost salts such as sodium, chloride and potassium. However, an electrolyte will encourage your horse to drink and therefore provide drinking water at all times during the day and night.
Anhydrosis is a frustrating condition that is hard to treat but can be managed. However, it is important to remember that anhydrotic horses run a real risk of heat exhaustion, which in some cases can lead to death.
So, please take care of your horses and watch out for any signs of your horse becoming dry-coated.
Always ensure that horses have adequate shade if they are out and plenty of drinking water available at all times.
