Coccidiosis in Poultry: Welfare and Control

Coccidiosis is a parasitic intestinal disease causing bloody diarrhea and high mortality in young chickens, representing a significant welfare burden in poultry production.

Key Facts

• Coccidiosis is caused by Eimeria species protozoa that destroy intestinal epithelial cells
• Bloody diarrhea, depression, and high mortality occur in susceptible flocks of young chickens
• Overcrowding, wet litter, and poor biosecurity dramatically increase disease risk
• Anticoccidial drugs in feed and vaccination are the primary control methods
• Immunity develops after natural exposure, but not before severe welfare harm in naive birds

Welfare Considerations

Coccidiosis causes acute intestinal suffering — the destruction of intestinal epithelium causes bloody diarrhea, abdominal pain, weakness, and rapid deterioration in young chickens. Mortality can be very high in naive populations without prevention. Survivors of severe infection may have permanently damaged intestinal function affecting long-term welfare and growth. Welfare-optimized coccidiosis management relies on: vaccination of chicks to stimulate controlled immunity development, anticoccidial medication in high-risk periods, litter management to reduce oocyst buildup, and adequate space to reduce fecal-oral contamination pressure. When outbreaks occur, immediate treatment with anticoccidials and electrolyte support is essential to limit suffering.

What You Can Do

• Ensure poultry producers use coccidiosis vaccination or prevention programs as standard practice
• Support litter management practices including dry litter maintenance to reduce oocyst survival
• Recognize coccidiosis symptoms in backyard flocks: bloody droppings, lethargy, huddling
• Seek immediate veterinary treatment for suspected coccidiosis — delay increases mortality and suffering
• Advocate for welfare-based coccidiosis control standards in poultry certification schemes