Evaluation of two methods for mass euthanasia of poultry in disease outbreaks

Abstract

Outbreaks of exotic Newcastle disease (END) and low pathogenic avian influenza (LPAI) in the United States forced the euthanasia of millions of birds during 2002 and 2003. Both diseases are caused by viral pathogens that can infect most species of birds. The viruses are highly contagious and infectious and may cause no clinical signs or clinical signs of mild (clinical signs associated with the respiratory system for LPAI and those associated with the respiratory, nervous, and digestive systems for END) to severe disease with high mortality rate. The severity of disease depends on multiple variables, including the strain of the virus, the species affected, host factors, and environmental stressors. The viruses spread to susceptible avian hosts primarily through direct contact with infected birds but also through indirect contact with contaminated equipment and materials. Feces and secretions from the eyes, nose, and mouth of infected birds contain the viruses. The LPAI outbreak in March 2002 was first detected in commercial poultry flocks in the Shenandoah Valley region of Virginia. 1 In October 2002, END was initially detected in small, backyard poultry flocks in California. 2