Changes

Also known as: '''''Bovine Viral Diarrhoea — Bovine Virus Diarrhoea (Virus) — [[Bovine Viral Diarrhoea Virus#Mucosal Disease|Mucosal Disease]]

Also known as: '''''Bovine Viral Diarrhoea — Bovine Virus Diarrhoea (Virus) — [[Bovine Viral Diarrhoea Virus#Mucosal Disease|Mucosal Disease]]

==Introduction==

==Introduction==

Bovine viral diarrhoea is a viral disease that affects cattle worldwide. Caused by a [[:Category:Pestiviruses|Pestivirus]], it gives rise to significant economic losses in both dairy and beef cattle through its effects on production and reproduction. Bovine viral diarrhoea virus can lead to a variety of clinical outcomes that range from subclinical infections to the more severe presentations including abortion, infertility, and the fatal mucosal disease. The condition is highly immuno-suppressive and secondary respiratory and enteric complications often occur.

Bovine viral diarrhoea is a viral disease that affects cattle worldwide. Caused by a [[:Category:Pestiviruses|Pestivirus]], it gives rise to significant economic losses in both dairy and beef cattle through its effects on production and reproduction. Bovine viral diarrhoea virus can lead to a variety of clinical outcomes that range from subclinical infections to the more severe presentations including abortion, infertility, and the fatal mucosal disease. The condition is highly immuno-suppressive and secondary respiratory and enteric complications often occur.

====Mucosal Disease====

====Mucosal Disease====

[[Image:Mucosal disease cartoon.jpg|right|thumb|150px|Cartoon depicting the development of mucosal disease (Courtesy Prof Joe Brownlie, RVC)]]

[[Image:Mucosal disease cartoon.jpg|right|thumb|200px|Cartoon depicting the development of mucosal disease (Courtesy Prof Joe Brownlie, RVC)]]

Mucosal disease is an invariably fatal condition of 6-18 month-old cattle<ref name="fofive">Brownlie, J (1990) '''Pathogenesis of mucosal disease and molecular aspects of bovine virus diarrhoea virus''' ''Veterinary Microbiology'', 23, 371-382.</ref>. Disease follows a course of several days to weeks and intially presents as pyrexia, depression and weakness. Anorexia leads to emaciation, and animals suffer watery, foul-smelling and sometimes bloody diarrhoea. Dehydration ensues. As suggested by the name, lesions are localised to mucosal surfaces. These include the oral mucosa, tongue, external nares, nasal cavities and conjunctiva<ref name="thone"/>, where large lesions  cause excessive salivation, lacrimation, and oculo-nasal discharge. The coronet and interdigital surface are also affected, causing the animal to become disinclined to walk and eventually recumbent.

Mucosal disease is an invariably fatal condition of 6-18 month-old cattle<ref name="fofive">Brownlie, J (1990) '''Pathogenesis of mucosal disease and molecular aspects of bovine virus diarrhoea virus''' ''Veterinary Microbiology'', 23, 371-382.</ref>. Disease follows a course of several days to weeks and intially presents as pyrexia, depression and weakness. Anorexia leads to emaciation, and animals suffer watery, foul-smelling and sometimes bloody diarrhoea. Dehydration ensues. As suggested by the name, lesions are localised to mucosal surfaces. These include the oral mucosa, tongue, external nares, nasal cavities and conjunctiva<ref name="thone"/>, where large lesions  cause excessive salivation, lacrimation, and oculo-nasal discharge. The coronet and interdigital surface are also affected, causing the animal to become disinclined to walk and eventually recumbent.

===Pathology===

===Pathology===

In cases of mild, acute BVD, lesions are rarely seen. When disease is more severe, the lymph nodes may appear swollen, there may be erosions and ulcerations of the gastrointestinal tract tract and serosal surfaces of the viscera may show petechial and ecchymotic hemorrhages<ref name="forty"/>.

In cases of mild, acute BVD, lesions are rarely seen. When disease is more severe, the lymph nodes may appear swollen, there may be erosions and ulcerations of the gastrointestinal tract tract and serosal surfaces of the viscera may show petechial and ecchymotic hemorrhages<ref name="forty"/>.

The pathology associated with mucosal disease is much more striking<ref name="thone"/>. Oral, lingual and buccal erosions are observed, and buccal lesions often coalesce to form larger areas of necrosis and sloughed epithelium. Oesophageal lesions present similarly. The gastrointestinal tract often shows characteristic pathology, but post-mortem examination must be performed soon after death so that these are not masked by autolytic changes. In the rumen, ulceration is less common but, with congestion and oedema, may be seen along the pillars, and papillae can be reduced in size. Several discoid erosions of around 5mm in diameter appear in the abomasum, with hyperaemia of the surrounding mucosa and petechiation of the submucosa, particularly at the pylorus. Abomasal erosions occasionally enlarge and ulcerate. Oval erosions can be seen along the antimesenteric surface of the small intestine, overlying the lymphatic tissue of the Peyer's patches and measuring 2-5 centimetres in length. The erosions become larger and more numerous towards the terminal ileum, and the exposed surfaces varies in appearance. In more chronic lesions, food is seen to adhere to the underlying submucosa, and in acute disease the exposed surface is acutely congested and often haemorrhages into the gut lumen. In the large intestine, the mucosal folds may be thickened, giving the organ a striped appearance inwardly. Petechiation and erosions are occasionally seen along the folds, and the large intestinal contents are watery, dark and foul-smelling.

The pathology associated with mucosal disease is much more striking<ref name="thone"/>. Oral, lingual and buccal erosions are observed, and buccal lesions often coalesce to form larger areas of necrosis and sloughed epithelium. Oesophageal lesions present similarly. The gastrointestinal tract often shows characteristic pathology, but post-mortem examination must be performed soon after death so that these are not masked by autolytic changes. In the rumen, ulceration is less common but, with congestion and oedema, may be seen along the pillars, and papillae can be reduced in size. Several discoid erosions of around 5mm in diameter appear in the abomasum, with hyperaemia of the surrounding mucosa and petechiation of the submucosa, particularly at the pylorus. Abomasal erosions occasionally enlarge and ulcerate. Oval erosions can be seen along the antimesenteric surface of the small intestine, overlying the lymphatic tissue of the Peyer's patches and measuring 2-5 centimetres in length. The erosions become larger and more numerous towards the terminal ileum, and the exposed surfaces varies in appearance. In more chronic lesions, food is seen to adhere to the underlying submucosa, and in acute disease the exposed surface is acutely congested and often haemorrhages into the gut lumen. In the large intestine, the mucosal folds may be thickened, giving the organ a striped appearance inwardly. Petechiation and erosions are occasionally seen along the folds, and the large intestinal contents are watery, dark and foul-smelling.

==Treatment and Control==

==Treatment and Control==

{{Joe Brownlie

{{Joe Brownlie

|date = July 8, 2011}}

|date = July 8, 2011}}

[[Category:Pestiviruses]][[Category:Cattle Viruses]][[Category:Alimentary Diseases - Cattle]][[Category:Reproductive Diseases - Cattle]]

[[Category:Pestiviruses]][[Category:Cattle Viruses]][[Category:Alimentary Diseases - Cattle]][[Category:Reproductive Diseases - Cattle]]

[[Category:Oral_Cavity_-_Erosive_&_Ulcerative_Pathology]]

[[Category:Oral_Cavity_-_Erosive_&_Ulcerative_Pathology]]

[[Category:Enteritis,_Ulcerative]][[Category:Enteritis,_Viral]] [[Category:Joe Brownlie reviewed]]

[[Category:Enteritis,_Ulcerative]][[Category:Enteritis,_Viral]] [[Category:Joe Brownlie reviewed]]