CLINICAL PATHOLOGICAL CHARACTERISTICS OF BLACKHEAD DISEASE OF CHICKENS IN THAI NGUYEN PROVINCE
Abstract
In order to identify some clinical, pathological characteristics and hematological changes in chickens which have blackhead disease raised in Thai Nguyen province, we dissected 872 chickens. The result of post mortem and examinations on 872 chickens showed that: On average the morbidity rates of blackhead disease caused by Histomonas meleagridis (H. meleagridis) was 18.69%. The main clinical symptoms of diseased chickens are moving more slowly, standing up with ruffled feathers, dropping wings, their heads hide under their wings, clossing their eyes, having high temperature to 43oC and more, drinking a lot of water, skin of the face and comb was pale or dark blue color, sulfur-yellow colored droppings. Lesions: enlargement of caeca with hemorrhagic and necrotic mucosa. Development of yellowish brown caseous exudate, in later stages, a white, dry and cheesy core. Enlargement of liver by 2 or 3 times with irregular - round depressed lesions, necrotic ulcers of liver look like of chrysanthemum flower shape. Blackhead disease diseased chickens have number of erythrocytes, the content of hemoglobin and average volume of erythrocytes decrease, number of leucocytes, thrombocytes, the rate of neutrophils, lymphocytes and monocytes also increase.