Highly Pathogenic Avian Influenza (Bird Flu) | Poultria
Scientific facts on Influenza A subtype genetics, comb cyanosis, and quarantine protocols.
Scientific Overview
Avian Influenza is caused by Influenza A viruses of the Orthomyxoviridae family. Strains are classified as Highly Pathogenic Avian Influenza (HPAI) or Low Pathogenic Avian Influenza (LPAI) based on genetic virulence markers. HPAI causes systemic vascular breakdown and near 100% flock mortality, posing a zoonotic pandemic threat.
Pathological Lesions & Shank Hemorrhages
HPAI (typically subtypes H5N1, H5N8, H5N2) causes severe systemic vascular hemorrhage: dark purple cyanosis of the comb and wattles, subcutaneous facial edema, pinpoint epicardial fat hemorrhages, and red petechial rings on the shank scales. Lungs are severely congested and consolidated with catarrhal exudate.
Regulatory Quarantine & Bio-exclusion
Due to its zoonotic potential, therapeutic treatment is prohibited. Outbreaks are managed via immediate quarantine, flock depopulation (culling), sanitary composting or burying of carcasses, and establishing strict bio-exclusion perimeters to prevent wild bird vectors from contacting domestic flocks.
All scientific data, diagnostic criteria, and performance benchmarks presented on this page are derived from published peer-reviewed journals and official veterinary codes:
- Avian Pathology & Diagnostics: World Organisation for Animal Health (WOAH, 2023). Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. Paris, France.
- Poultry Diseases & Histology: Swayne, D.E., et al. (2020). Diseases of Poultry (14th ed.). Wiley-Blackwell / American Association of Avian Pathologists.
- Nutrition & Feed Chemistry: Leeson, S. & Summers, J.D. (2001). Commercial Poultry Nutrition (3rd ed.). University Books, Guelph, Ontario.
- Commercial Breed Standards: Aviagen (2024). Ross 308 & Cobb 500 Broiler Performance Objectives. / Lohmann Breeders (2024). Lohmann Brown Management Guide.