Getting to the Bottom of Chronic Idiopathic Anhidrosis

A genomic study of horses with CIA found the condition is highly heritable. Here’s what else the researchers learned about horses that don’t sweat.

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Getting to the Bottom of Chronic Idiopathic Anhidrosis
Chronic idiopathic anhidrosis (CIA) is a lifelong inability to sweat, with no known cause. Cold water hosing can help keep these horses cool. | Photo: iStock
Nonsweater. It’s the term we often give horses with anhidrosis, a condition characterized by the inability to sweat. Because horses are one of only three species that use sweat as their main thermoregulatory method, not being able to sweat is a big deal.

During the University of Florida Veterinary Extension’s 2020 Healthy Horses Conference, Laura das Neves Patterson Rosa, DVM, PhD, described this condition and what researchers are learning about it.

What Is CIA?

Chronic idiopathic anhidrosis (CIA) is a lifelong (sometimes seasonal, sometimes year-round) inability to sweat, with no known cause. Common signs include:

  • A dry coat;
  • Rapid breathing;
  • Decreased appetite and water intake;
  • Alopecia (hair loss); and
  • Depression.

“The risk is that animals with this condition can overheat, which can lead to heat shock, convulsions, and even death,” Patterson Rosa said

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Written by:

Alexandra Beckstett, a native of Houston, Texas, is a lifelong horse owner who has shown successfully on the national hunter/jumper circuit and dabbled in hunter breeding. After graduating from Duke University, she joined Blood-Horse Publications as assistant editor of its book division, Eclipse Press, before joining The Horse. She was the managing editor of The Horse for nearly 14 years and is now editorial director of EquiManagement and My New Horse, sister publications of The Horse.

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