Black Head in Poultry

Black Head (Histomonosis, Enterohepatitis)

Cause

It is caused by a protozoan parasite Histomonas meleagridis.

Transmission

Infected water, feed or droppings play a role in transmission of the protozoa (direct transmission). The infected eggs of the caecal worm Heterakis gallinarum is also responsible for  the transmission (indirect transmission).

Species affected

It affects both the chickens, turkeys and peafowl. But the young chickens are more susceptible

Clinical signs and lesions

There is depression, ruffled feathers and yellowish diarhhoea.  The turkeys have dark head parts so the disease is known as black head. Mortality is higher, particularly in young turkey but the mortality is lower in young chickens. The infection can be also be seen in older birds.

Upon postmortem examination, liver has circular necrotic areas with a crater like centre and the caeca has cheesy cores.

Diagnosis

It can be diagnosed on the basis of clinical signs and postmortem findings

Treatment

The protozoan drugs can be given in starter and grower feeds for turkeys. The incidence of the disease can be minimized by growing turkeys on wire and indoors. The caecal worms should be eliminated and strict hygiene should be maintained.

Source: farmnepal.com.np