Equine sweating and anhidrosis Part 2: anhidrosis.

Area of Science:

• Equine physiology
• Veterinary dermatology
• Environmental stress response

Background:

• Anhidrosis is a condition characterized by the inability to sweat.
• It affects a subset of the equine population, particularly in hot and humid climates.
• The exact mechanisms underlying anhidrosis are not fully understood.

Purpose of the Study:

• To review the current understanding of anhidrosis in horses.
• To explore the latest theories on the causal factors of anhidrosis.
• To identify areas for future research.

Main Methods:

• Literature review of existing studies on anhidrosis.
• Analysis of evidence supporting current hypotheses on causation.
• Identification of knowledge gaps in equine sweat gland physiology.

Main Results:

• Evidence supports anhidrosis as an inappropriate response to prolonged climatic stress (heat and humidity).
• The condition affects approximately 10% of horses.
• Pathophysiology involves gradual failure of glandular secretory cells due to receptor desensitization and down-regulation from adrenaline-driven hyperactivity.
• This progresses to secretory failure, glandular dedifferentiation, and degeneration.

Conclusions:

• Anhidrosis in horses is linked to prolonged heat and humidity stress.
• The underlying mechanism involves progressive failure of sweat gland secretory cells.
• Further research into secretory and transcriptional processes is needed for treatment development.