Canine Respiratory Parasites Study Guide

Overview and Clinical Importance

Canine respiratory parasites encompass a diverse group of nematodes and trematodes that inhabit the airways, lung parenchyma, and pulmonary vasculature of dogs. These parasites cause clinical signs ranging from subclinical infection to severe, life-threatening cardiopulmonary disease. Key parasites tested on the NAVLE include lungworms (Oslerus osleri, Crenosoma vulpis, Filaroides hirthi), the French heartworm (Angiostrongylus vasorum), lung flukes (Paragonimus kellicotti), and respiratory capillarids (Eucoleus aerophilus).

Understanding the life cycles, geographic distribution, diagnostic approaches, and treatment protocols for these parasites is essential for the NAVLE. Many require intermediate hosts (gastropods or crayfish), which influences transmission patterns and geographic distribution.

Classification of Canine Respiratory Parasites

Oslerus osleri (Tracheal Lungworm)

Oslerus osleri (formerly Filaroides osleri) is the most common respiratory nematode in dogs worldwide. Adults reside in nodules at the tracheal bifurcation and mainstem bronchi, causing characteristic granulomatous lesions visible on bronchoscopy.