Necrotizing Hepatitis Associated with Clostridium perfringens in Broiler Chicks

Area of Science:

• Veterinary Pathology
• Poultry Disease Research
• Bacterial Infections in Poultry

Background:

• Unusual cases of clostridial hepatitis with high mortality were observed in young broiler chicks.
• The condition presented with significant mortality rates, affecting flocks across multiple companies.

Purpose of the Study:

• To comprehensively evaluate clostridial necrotizing hepatitis in newly hatched chicks.
• To identify causative agents, clinical signs, gross and histopathological lesions, and potential sources of infection.

Main Methods:

• Retrospective analysis of eleven cases submitted between 2017 and 2020.
• Gross examination, histopathology, immunohistochemistry for *Clostridium perfringens*, bacterial culture, and toxinotyping by PCR were performed.

Main Results:

• Gross lesions included discolored livers, lung congestion, abdominal fluid, and yolk sac emphysema.
• Histopathology revealed necrotizing hepatitis associated with gram-positive rods; *Clostridium perfringens* was confirmed by IHC and PCR.
• Toxinotyping identified genes for alpha toxin (cpa/plc), necrotic enteritis toxin B-like (netB), and *C. perfringens* large cytotoxin (tpeL).

Conclusions:

• Broiler breeders are suspected as the source of *Clostridium perfringens* infection.
• Combined antimicrobial therapy and enhanced farm/hatchery sanitation significantly reduced mortality and clinical signs.
• This study provides the first comprehensive evaluation of clostridial necrotizing hepatitis in newly hatched chicks.