Blackhead disease in chickens is caused by a single type of Histomonas parasite in the liver, stomach, appendix. The disease is spread through eating and drinking eggs of pinworms containing Histomonas protozoan, which is common in chickens 2-3 weeks old to 3-4 months of age. The disease causes great damage to chicken farmers.
Read Mavin Animal Health’s advice on prevention and treatment HERE
