Avian Enteritis Study Guide

Overview and Clinical Importance

Enteritis refers to inflammation of the intestinal tract and represents one of the most economically devastating disease categories in avian species. In poultry, enteric diseases cause billions of dollars in annual losses worldwide through mortality, reduced growth rates, poor feed conversion, and decreased egg production. For pet birds, enteritis can be life-threatening and requires prompt veterinary intervention.

Avian enteritis encompasses a diverse group of infectious and non-infectious conditions affecting the gastrointestinal tract. The NAVLE frequently tests knowledge of major enteric pathogens including Clostridium perfringens (necrotic enteritis), Eimeria species (coccidiosis), turkey hemorrhagic enteritis virus, coronaviruses, and various bacterial pathogens. Understanding the pathogenesis, clinical presentation, diagnosis, and treatment of these conditions is essential for NAVLE success.

Section 1: Bacterial Enteritis

Necrotic Enteritis (Clostridium perfringens)

Etiology and Pathogenesis

Clostridium perfringens types A and C are the causative agents of necrotic enteritis (NE). This gram-positive, anaerobic, spore-forming bacterium is a normal inhabitant of the avian intestinal tract. Disease occurs when predisposing factors allow bacterial overgrowth and toxin production. The key toxins include alpha-toxin (phospholipase C) and NetB toxin (necrotic enteritis B-like toxin), which cause intestinal mucosal necrosis.