Canine Tetanus Study Guide

Overview and Clinical Importance

Tetanus is a severe, life-threatening neurologic disease caused by tetanospasmin, a potent neurotoxin produced by Clostridium tetani, a gram-positive, anaerobic, spore-forming bacillus. The disease results in characteristic spastic paralysis due to inhibition of inhibitory neurotransmitter release in the central nervous system.

Dogs are relatively resistant to tetanus compared to horses and humans (approximately 600 times more resistant than horses). The minimal lethal dose of tetanus toxin in dogs is 150 ng/kg compared to 0.2 ng/kg in horses. This relative resistance means vaccination is not routinely recommended in dogs, unlike horses and humans.

For the NAVLE, understanding tetanus is essential because it represents a classic example of clostridial neurotoxicosis and is frequently tested due to its distinctive clinical presentation, the importance of wound management, and the requirement for intensive supportive care.