Anhidrosis in Horses
Anhidrosis is defined as the inability to sweat. This problem in horses usually develops over time but can occur acutely. Since horses depend on their ability to sweat to help regulate body temperature like humans do, it can quickly become a serious condition, leading to hyperthermia and heat stress.
When suffering from anhidrosis, some horses retain some ability to sweat in certain areas. But the majority are unable to sweat in most areas of their body.
Symptoms and Types
- Panting after exercise, or while standing
- Weakened performance
- Decrease in appetite
- Increased heart rate
- Increased respiratory rate
- Occasionally, patchy sweat
The exact cause of anhidrosis is unknown, although it may be the result of a cellular defect within the sweat gland. Excessive heat and humidity can exacerbate it.
The clinical signs of this condition make it fairly straightforward to diagnose. Your veterinarian may give an injection of epinephrine to help induce sweating, and if the horse’s sweat glands are functional, the horse will sweat until the hormone injection is depleted. After diagnosis, treatment can begin.
There is no specific treatment for anhidrosis. Instead, the goal of treatment is to manage the condition and keep the horse as comfortable as possible. For an acute attack, the veterinarian will administer a fever-reducing agent such as flunixin meglumine (Banamine). Cold-water therapy should also be started to bring the horse’s body temperature down as quickly as possible. IV fluids and electrolytes may sometimes be given, depending on the state of the horse.
For continued management, moving the horse to a cooler environment will help. The addition of an air-conditioned stall, or at least a fan will greatly help, as will changing the horse’s exercise schedule to only occur during cooler parts of the day or in the evening. The addition of electrolytes to the water during the summer will help as well, in addition to body clipping the horse.
True anhidrosis cannot be prevented. The best way to prevent future attacks is to move the horse to a cooler environment.