Blackhead disease can affect many different poultry species, including chickens, turkeys, and game birds. Because the severity of Blackhead disease is different for each species, we strongly recommend that all poultry species be housed separately as much as possible.
For chickens, the symptoms of Blackhead disease can range from a slight drop in egg production to lethargy, decreased appetite, anemia, and death. Many times a flock may not show symptoms and can appear healthy while carrying the disease.
Blackhead disease in turkeys, however, can be much more severe, especially in young poults. Turkeys with Blackhead disease may first appear depressed, with drooping wings, little appetite, closed eyes, and general malaise. As the disease progresses, damage to the infected bird’s cecum and liver leads to death. From infection to appearance of first symptoms is approximately 7 to 14 days.
This disease is caused by Histomonas meleagridis, which is a protozoan parasite that resides in a parasitic cecal worm egg. This worm is passed through the infected bird via fecal matter and then eaten by another bird directly from the feces or through other means, such as an earthworm that has eaten the worm egg. It is a vicious cycle that is very difficult to put a stop to once it has started. This protozoan can survive in the ground for approximately three years when the conditions are right. The only way to get rid of the disease is to remove the poultry and wait 3 years before bringing in any new birds.
For any bird that is showing signs of illness, isolation is the first step. Move the sick bird into a comfortable, quiet isolation pen with easy access to food and water. Treatment will need the help of your poultry veterinarian who can prescribe antiprotozoal medications.
Keeping chickens and turkeys separated from each other on your homestead will go a long way to prevent transmission between species. A regular deworming schedule to keep the infection rate of the cecal worm in check within your flock is also an important step in preventing Blackhead disease. Regular removal of fecal matter also is important for the control of many poultry illnesses, not just Blackhead.