Equine Drug Toxicities Study Guide

Overview and Clinical Importance

Drug toxicities represent a critical area of equine medicine frequently tested on the NAVLE. Horses are unique in their susceptibility to certain drug adverse effects due to their gastrointestinal physiology, body size variations, and sensitivity to specific drug classes. Understanding the mechanisms, clinical presentations, and management of common drug toxicities is essential for safe equine practice.

This study guide covers the most clinically significant and NAVLE-relevant drug toxicities in horses, including NSAIDs, aminoglycosides, macrocyclic lactones, corticosteroids, sedatives, tetracyclines, and reproductive hormones.

1. Non-Steroidal Anti-Inflammatory Drug (NSAID) Toxicity

NSAIDs are among the most commonly used drugs in equine practice and have a reportedly narrow margin of safety. The three primary manifestations of NSAID toxicity are renal papillary necrosis, equine gastric ulcer syndrome (EGUS), and right dorsal colitis (RDC).