Clinical manifestation and postmortem findings
The current study focused on infected chickens of the Ross breed. IBH occurred in 46 farms around Sulaymaniyah governorate in the Kurdistan of Iraq, and the clinical signs in 2–3 week-old broiler chicks included lethargy, huddling with ruffled feathers, inappetence, and yellow mucoid droppings.
The mortality rates ranged between 8% and 15%, and postmortem findings included pale icteric skin and ecchymotic hemorrhages on the skeletal muscles (Figure 1A). Enlarged, pale, and mottled liver (Figure 1B and 1C), swollen pale kidney with distended tubules (Figure 1D). The bursa of Fabricius and thymus had not atrophied. The bone marrow was red.