ASCITES SYNDROME IN BROILER-CHICKENS

This review article has summarized the most important knowledge on the ascites syndrome (AS) of broiler chickens [other nomenclature: pulmon ary hypertension syndrome (PHS), right ventricular hypertrophy (RVH) s yndrome] based mainly on literature data and partly on own diagnostic observations of the authors. Internal predisposing factors (anatomical and physiological) have been treated together with the external, non- infectious and infectious etiology which may play a role in the manife station of ascites due to morphological and functional damaging certai n organs or blood vessels. During the clinical examination enlargement of the abdominal cavity and ascites, as well as dyspnoea, tachypnoea and cyanosis can be observed. The haematological investigations reveal ed increase of red cell counts, general cell size, haemoglobin and pac ked cell volume values meanwhile the protein level of blood plasma dec reased due to the ''protein loss'' towards the abdominal cavity. The p athological examinations revealed accumulation of yellowish, watery, t ransparent fluid containing sometimes gelatin-like plasma coagulation and occasionally fibrin flakes in the peritoneal and abdominal cavitie s and in the pericardium. The serosa of the swollen liver is enlarged, becomes fuliginous and the surface is frequently covered by a fibrin layer. Right atrium and ventricle of the heart, as well as the inferio r and superior vena cava are dilated. The wall of right ventricle is e nlarged. Congestion plethora can be seen in the lungs and other organs . The histological investigations revealed oedema in the myocardium wi th degeneration of certain muscle cells, slight proliferation of fibro blasts and heterophyl granulocytic infiltration. Congestion plethora a nd oedema were observed in the lungs. Sinusoids in the liver are dilat ed and part of the hepatic cells are degenerated due to hypoxia. The G lisson's capsule is enlarged because of the proliferation of mesotheli al cells. The electron microscopic investigation of the lungs revealed swelling of the endothel cells of capillaries, as well as enlargement of the basal membrane of the respiratory epithelium. Myofibrillar deg eneration was observed in the heart and swelling of the mitochondria w ith fragmentation of their crysta. Diagnosis of primary or secondary a scites accompanying other diseases is a complex task and not always po ssible due to the characteristic but similar clinical symptoms and pat hological changes. Detection of the management, metabolic, toxic or in fectious causes are required to control and prevent the disease which needs complex laboratory diagnostic investigations and careful examina tion of the management conditions of the animals on the spot.