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Bovine Viral Diarrhoea Virus (view source)
Revision as of 13:05, 24 August 2010
, 13:05, 24 August 2010→Pathology
===Pathology===
===Pathology===
[[Image:Bvd2.gif|right|thumb|150px|Coalescing lesions of BVDV (Courtesy of Alun Williams, RVC)]]
[[Image:Bvd2.gif|right|thumb|150px|Coalescing lesions of BVDV (Courtesy of Alun Williams, RVC)]]
Much useful information can be gained from a detailed post
mortem examination of suspected cases of mucosal disease.
The full extent of oral, lingual and buccal erosions should be
observed. A common finding in the buccal mucosa is that the
small erosions have coalesced into larger areas of necrosis and
sloughed epithelium.
Similar erosions may be seen in the oesophagus. Ruminal
lesions, if present, are areas of congestion and oedema along
the ruminal pillars. Ulceration is rare. The large ruminal
papillae can be reduced in size.
The abomasum and small intestine provide the most
reliable sites for inspection but immediate autopsy is important
as post mortem changes in the gut are rapid and gaseous
extension can often mask the enteric erosions.
The abomasum usually shows several (five to 50) small
discoid erosions, about 5 mm diameter, with surrounding
hyperaemia in the mucosa. Submucosal petechial haemor-
rhages are a common finding, particularly in the pylorus (Fig
6). Occasionally, the erosions can be larger and ulcerated.
The small intestine, if opened throughout its length to
expose the antimesenteric surface, will reveal oval erosions
(2 cm to 5 cm long) that overlie the lymphatic tissue in Peyer's
patches. The erosions may vary from two to three to 30 to 40.
Towards the terminal ileum the erosions can become extensive
and may be up to 10 to 20 cm in length. The exposed
submucosal surface of the erosions can vary from the chronic
lesion, with food adhering (Fig 7), to the acutely congested
one often with interluminal haemorrhage.
In the large bowel, there may be congestion of the mucosa
which gives a thickening to the mucosal folds and a striped
appearance. There may also occasionally be petechial
haemorrhages and small erosions along the folds. The
contents are dark, watery and often foul smelling.
Gross lesions seldom are seen in cases of mild disease.
Gross lesions seldom are seen in cases of mild disease.