Avian Coccidiosis: A Major Parasitic Disease of Poultry Industry

Abstract

Avian coccidiosis is a serious parasitic disease that affects chickens, and is caused by the intracellular apicomplexan protozoa Eimeria. The disease is fatal and targets the intestinal tract. Seven species of Eimeria are found in chickens, including the most prevalent, Eimeria acervulina, Eimeria maxima, and Eimeria tenella. These bacteria infiltrate the intestinal epithelial cells in a particular location of the gut and cause variable degrees of tissue damage and morbidity. The intricate life cycle of Eimeria consists of both intracellular and extracellular stages that trigger a strong inflammatory response. This response leads to tissue damage brought on by lipid peroxidation and oxidative stress, diarrheal bleeding, stunted growth, increased susceptibility to other disease agents, and, in extreme cases, death. The severity of coccidian infection depends on the age of the birds, Eimeria species, number of sporulated oocysts ingested, immune status of the bird, and environmental management. Coccidiosis in chickens is characterized by dysentery, enteritis, emaciation, drooping wings, poor growth, and low production, with a high rate of mortality and morbidity. Anticoccidials are drugs used for the prevention and control of coccidian infections. They can either be coccidiocidal or coccidiostatic. The most commonly used drugs are sulphonamides, amprolium, and toltrazuril. Today, the prevention and control of coccidiosis are based on chemotherapy, using anticoccidial drugs or vaccines, along with hygienic measures and improved farm management. This current review highlights the prevention and control of avian coccidiosis.