Identity

An acute enterotoxemic bacterial disease affecting broiler poultry caused by Clostridium perfringens. Triggered by mucosal damage, the bacteria rapidly proliferate and release pore-forming toxins (NetB/alpha-toxin) that induce severe coagulative necrosis of the small intestinal mucosa.

Overview

Necrotic Enteritis is a major commercial bacterial pathogen in the broiler industry. It is driven by Clostridium perfringens Type A and C strains. Pathogenesis strictly depends on predisposing factors—most notably mucosal damage by Eimeria (coccidiosis) or high-viscosity diets (wheat/barley)—which allow the anaerobic bacteria to overgrow and secrete potent toxins. These toxins destroy the jejunal mucosa, causing severe performance loss and high mortality. Prevention requires managing coccidiosis, using feed enzymes (xylanases) for viscous diets, and feed-additive bacitracin methylene disalicylate (BMD).

Structured Facts

Classification

Bacterial > Infectious Pathogen

Epidemiology

• Severity: High
• Affected Species: Poultry (Broilers)
• Affected Age: Young broilers between 2 and 6 weeks of age
• Transmission: Horizontal via ingestion of bacterial spores from contaminated litter, soil, or feed
• Mortality: Up to 50% in acute untreated outbreaks
• Morbidity: 10% to 40%
• Economic Importance: High (Performance loss, high FCR, mortality)

Clinical Signs

• Early/Intermediate: Subclinical: poor feed conversion and reduced weight gain. Clinical: severe depression, somnolence, dehydration, reluctance to move
• Advanced: Sudden onset high mortality, dark foul-smelling fluid feces; targets Gastrointestinal system (Small Intestine)
• Postmortem Findings: Thin-walled, distended small intestine. Mucosa covered by a dense, yellowish-brown, pseudomembranous layer resembling a "Turkish towel". Coagulative necrosis.

Diagnosis

• Field Diagnosis: "Turkish towel" necrosis in jejunum
• Laboratory Tests: Large Gram-positive rods in mucosal smears, anaerobic isolation on blood agar (double zone of hemolysis), PCR for NetB gene, Histopathology
• Differential Diagnosis: Coccidiosis (E. maxima / E. necatrix)

Treatment

• Immediate Actions: Control Eimeria levels, alter diet viscosity
• Medicines: Bacitracin Methylene Disalicylate (BMD)
• Veterinary Intervention: Guided by SVTG

Prevention

• Vaccination: None mentioned
• Biosecurity: Mitigated by standard Biosecurity Protocols
• Farm Management: Dietary management: Supplement viscous grain diets with enzymes (xylanases). Administer feed-additive BMD at 50g/ton. Strict coccidiosis control.

Quantitative Data

• Morbidity Rate: 10% to 40%
• Mortality Rate: Up to 50% (Acute)
• Target Age: 2 to 6 weeks
• BMD Dosage: 50g/ton of feed

Relationships

• Vaccines: None
• Medicines: Bacitracin Methylene Disalicylate (BMD), Xylanase enzymes
• Biosecurity: Biosecurity Protocols
• Predisposing Relationships: Eimeria spp. (Coccidiosis), High-viscosity diets (wheat/barley/rye)