Avian Giardiasis Study Guide

Overview and Clinical Importance

Avian giardiasis is an intestinal protozoal infection caused by Giardia psittaci (in psittacines) and Giardia ardeae (primarily in herons and waterfowl). This parasitic disease is particularly significant in companion bird practice, with cockatiels, budgerigars, lovebirds, and grey-cheeked parakeets being most commonly affected. Giardiasis is a frustrating disease to manage due to its intermittent shedding patterns, difficulty in achieving complete cure, and high potential for reinfection from environmental contamination.

The clinical significance extends beyond simple diarrhea, as affected birds may exhibit characteristic feather-picking behavior in specific anatomical regions (axillary and inner thigh areas), particularly in cockatiels. Understanding the life cycle, diagnostic challenges, and treatment protocols is essential for NAVLE success and effective clinical practice.

Etiology and Pathogenesis

Causative Agents

Giardia species are flagellated protozoan parasites belonging to the phylum Metamonada and order Diplomonadida. Two species are recognized as causing avian giardiasis: