Equine Dermatitis Study Guide

Overview and Clinical Importance

Dermatitis in horses encompasses a broad spectrum of inflammatory skin conditions that represent some of the most frequently encountered dermatological problems in equine practice. These conditions range from mild, self-limiting reactions to severe, debilitating diseases that significantly impact equine welfare and performance. Understanding the etiology, clinical presentation, and management of equine dermatitis is essential for the NAVLE examination and clinical practice.

Equine dermatitis conditions can be broadly categorized into infectious (bacterial, fungal, parasitic), allergic/hypersensitivity (insect bite hypersensitivity, atopic dermatitis, contact dermatitis), and environmentally-induced (photosensitization, pastern dermatitis) causes. The skin serves as the body's largest organ and primary barrier against environmental insults, making accurate diagnosis and treatment of dermatological conditions critical for maintaining overall equine health.

Pastern Dermatitis (Scratches/Mud Fever)

Definition and Terminology

Equine pastern dermatitis (EPD) is a multifactorial syndrome rather than a single disease entity. It manifests as inflammatory cutaneous lesions on the distal extremities, typically affecting the palmar/plantar aspect of the pastern region. Common lay terms include scratches, mud fever, greasy heel, mud rash, dew poisoning, cracked heels, and grapes (for the chronic proliferative form).