The transition from summer to autumn is the time of year when chicken coccidiosis is most prevalent. Once the disease occurs, even timely treatment can result in substantial economic losses. Prevention is therefore essential.
Disease characteristics: The disease generally occurs from 6 to 10 each year. The high temperatures and humidity during this period are conducive to coccidia growth and development. Chicks aged 3 to 5 weeks are most susceptible to infection. Adult chickens are also susceptible to coccidia, but their symptoms are generally milder. Infected chickens are a source of infection. Feed, drinking water, and equipment contaminated by sick chickens may all contain oocysts. Ingestion of infective oocysts is the main route of transmission; flies and rodents are mechanical vectors. Reduced resistance, deficiencies of vitamins A and K in the feed, and malnutrition can all trigger the disease.
Clinical signs and gross lesions: Cecal coccidiosis has characteristic features and is relatively easy to diagnose. Affected chickens have pale combs, appear lethargic, huddle together, hold their wings drooping, and have ruffled feathers. They pass loose, bloody droppings or blood alone. The disease progresses rapidly, and deaths may occur within 2 to 3 days. If treatment is not timely, chick mortality can exceed 50%. Necropsy may reveal obvious anemia throughout the body, with pale muscles or internal organs. The main internal lesions are in the ceca, which become several times thicker than normal and dark red. When cut open, the cecal walls are thickened, and the contents consist of blood and blood clots. The main lesions of small-intestinal coccidiosis are in the anterior small intestine: the intestinal lumen is dilated, the serosa is congested and densely covered with millet-sized hemorrhagic spots, the intestinal wall is thickened, and the intestinal mucosa is congested and necrotic.
Preventive measures: Do not raise chicks on litter; always use cages. Before chicks arrive, thoroughly disinfect the brooding room. Repeatedly wash and disinfect the floor, cages, water troughs, and feed troughs with hot alkaline water. Maintain daily environmental hygiene, promptly remove manure from the poultry farm, and transport it to a remote location for harmless treatment. Disinfect 2 to 3 times per week. Keep the poultry house dry, maintain humidity and ventilation, and provide the flock with a comfortable environment. Improve husbandry management to increase the birds’ resistance, formulate rations appropriately, and meet their nutritional requirements. Young chickens have the highest requirement for vitamin K. Adequate vitamin A and vitamin D supplementation can also greatly help reduce the incidence of this disease. In addition, chicks can be given preventive medication at 20 days of age, 1 times, for 3 days. In areas with a serious environmental threat, administer another dose at 40 days of age, for 1 time(s).
Treatment measures: If the disease occurs, it can be treated with medication. Many medicines are effective against the disease, but treatment must be combined with disinfection and manure removal. Oocysts can survive for a long time in damp manure, and disinfectants have little effect on them. Manure must therefore be removed daily. After cleaning, scrub the manure boards with caustic soda solution, then cover them with quicklime.
Nutritional supplementation is also important. Use double doses of multiple vitamins and continue for about 10 days to eradicate the disease completely.
Commonly used medications include halofuginone, sulfaquinoxaline, chloroparguanide, Coccidiol, and penicillin. They should be rotated according to a plan or used in combination. Ensure the course of treatment is adequate and aim to cure the disease in one course to avoid drug resistance, which would make subsequent treatment more difficult.