Changes

===Pathology===

===Pathology===

Necrosis of the left ventricular papillary muscle and petechiation, ecchymoses or haemorrhages in the wall of the pulmonary artery have been described as "pathognomic" lesions for bluetongue. However, pulpy kidney disease and Rift Valley fever may occasionally cause similar lesions in sheep, and the lesions may be difficult to visualise in mild or recovering cases. Haemorrhage and necrosis may be found in other locations where fragile capillaries are damaged by mechanical abrasion. These can include the buccal oral mucosa, the mucosa of the oesophageal groove and the omasal folds as well as the skeletal muscle, myocardium and the intestines. Post-mortem examination may also reveal subcutaneous and intermuscular oedema, hydrothorax or hydropericardium, pericarditis, and pneumonia.

A haemorrhagic gross pathology of BTV infection reflects the endothelial damage responsible for disease pathogenesis. Certain lesions have been describes as "pathognomic" for bluetongue: these include necrosis of the papillary muscle in the left ventricle, and haemorrhage in pulmonary arterial wall. However, these lesions may be difficult to visualise in mild or recovering cases and may occasionnally occur in other diseases such as pulpy kidney disease or Rift Valley fever.

 

2–15 mm in diameter, in the tunica media at the base of the pulmonary artery are

gastrointestinal tract are found in and around the mouth. There is oedema and

hyperaemia in the mucosa, which is occasionally cyanotic. Petechial or ecchymotic

material, are found on the lips, dental pad, tongue and cheeks. Hyperaemia of the

ruminal pillars and reticular folds is common.

necrosis are scattered through the skeletal musculature. There is inflammation of the

upper respiratory tract causing excess mucus secretion (catarrhal inflammation), and

6.10 Histologically, there is damage to the endothelium of small blood vessels. This

oxygen and sloughing of the epithelium.

Experimental Australian cases exhibited haemorrhages, inflammatory mononuclear

cell infiltrations and necrosis of the heart muscle (myocardium).

==Treatment==

==Treatment==