Equine Medicine NAVLE Complete Guide: Respiratory, Metabolic, GI, and Reproduction

Equine medicine accounts for roughly 14.7% of NAVLE questions—the third-largest species block after canine and feline. That is about 53 questions in a 360-question exam. You cannot afford to skip large animal, but you also do not need to become a specialist. You need to know the high-yield conditions cold: respiratory, metabolic, GI emergencies, and reproduction.

Equine Respiratory Disease

Recurrent Airway Obstruction (RAO / Heaves)

RAO is equine asthma. Exposure to hay dust, mold, and endotoxins triggers airway hyperreactivity in susceptible horses. The classic patient is a stabled horse fed dry hay in a poorly ventilated barn.

Clinical signs progress over time: a dry chronic cough first, then exercise intolerance, then at-rest respiratory effort. The heave line—a visible muscular ridge along the ventral abdomen from hypertrophy of the external abdominal oblique—develops from chronic forced expiration. Horses with severe RAO breathe with nostril flare at rest and use an exaggerated abdominal push to exhale.