Anhidrosis

After a hard workout or on a hot day you expect to see your horse sweating however some horses can suffer from a condition called Anhidrosis which is the inability to sweat adequately. Anhidrosis is a condition most commonly seen in horses living in hot and humid climates and can affect any horse regardless of age, sex or breed.

Anhidrosis can be a very serious condition as horses need to sweat in order to effectively cool their core body temperature. The evaporation of sweat on the horse’s body is how they cool their body temperature during hot weather or exercise. If a horse is not sweating effectively for the circumstances it can lead to overheating, heat stroke and be potentially fatal.

The exact cause of Anhidrosis is not known although there are some indications that environmental and exercise stress, metabolic issues and hereditary factors are involved. It can sometimes be difficult to diagnose but some signs to look out for include;
– A dry coat after exercise or during very hot weather. They can be completely dry or dry except for being a little damp under tack and between the hind legs.
– Increased respiratory rate, heavy breathing, flared nostrils and/or shallow breaths after or during exercise or on hot days.
– Increased temperature.
– Lethargy, poor performance and/or decreased stamina.
– A poor dull coat with possible hair loss or thinning and/or dry, flaky skin.

There is a test that your veterinarian can do called a “Sweat Test” to diagnose Anhidrosis. This involves the veterinarian injecting a drug under the skin to cause localised sweating, if the horse does not sweat it can be determined that they do have Anhidrosis.

With no known cure for Anhidrosis it becomes about how to manage the condition and avoid overheating. Some suggested methods to help a horse with Anhidrosis include;
– Moving the horse to a cooler climate with less humidity.
– Exercise them in the cooler times of the day like early morning or the evening.
– Have the horse as fit as possible when coming into hotter months to reduce the stress during exercise.
– Cool them down after exercise or during hot weather by using cold water and fans.
– Provide them with shade during the day and if kept in stables ensure it is well ventilated and use a fan.

If you ever have any concerns about your horse or suspect that they could have Anhidrosis you should consult your veterinarian for further advice on diagnosis and management.