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Examples:
 
Examples:
====Acute bovine pulmonary emphysema and oedema (ABPEE)====
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[[Image:Fog fever 1.jpg|right|thumb|150px|<small><center>Fog fever (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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[[Image:Fog fever 2.jpg|right|thumb|150px|<small><center>Fog fever (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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[[Image:Tracheal haemorrhage in fog fever.jpg|right|thumb|150px|<small><center>Tracheal haemorrhages in fog fever (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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*Synonym: '''fog fever'''
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====[[Acute Bovine Pulmonary Emphysema and Oedema]]====
*Usually seen in adult beef cattle in the autumn as an outbreak
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*Associated with a change in pasture (from dry to lush, green)
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*Severe respiratory distress with laboured breathing and grunting on expiration
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*Can result in [[Diffuse Fibrosing Alveolitis|diffuse fibrosing alveolitis]]
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*Gross appearance is that of enlarged wet lungs, the interlobular septa are markedly widenedith [[Pulmonary Oedema|oedema]] and [[Pulmonary Emphysema|emphysema]]
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*Underlying pathogenesis is ingestion of L-tryptophan in the pasture which is metabolised to 3-methylindole  -> bloodstream -> lungs -> metabolised into a compound toxic to Type 1 pneumonocytes and non-ciliated bronchiolar epithelium
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*Their loss allows massive flooding of the alveoli with a protein-rich fluid
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*The sequence of events in the lung is as follows:
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**Alveolar flooding with a protein-rich fluid due to the necrosis of Type 1 epithelium
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**As the incoming air dries this fluid, fibrinous 'hyaline membranes' form
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**Proliferation of the more resistant cuboidal Type 2 epithelium which line the alveoli, called 'epithelialisation'
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**Then either there is
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***Digestion of the hyaline membranes by macrophages which when completed, allows some of the proliferated Type 2 epithelium to differentiate into Type 1 and reconstitute the functional respiratory unit - a normal alveolus
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**Or
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***Organisation of the fibrin into fibrous tissue in the lumen - destroying the alveolus or proliferation of fibrous tissue in the alveolar wall with retention of the epithelialised appearance to the alveolus
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*Sequel
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**Residual scarring if animal survives initial onslaught
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**In chronic exposures there may be extensive fibroplasia
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*Ingestion of sweet potatoes ifested with ''Fusarium solani'' mould or pasture contaminated with stinkweed or purple mint, rapeseed and kale also cause pulmonary oedema, emphysema and interstitial pneumonia
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[[Image:Paraquat poisoning.jpg|right|thumb|150px|<small><center>Paraquat poisoning (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
      
====[[Paraquat Poisoning]]====
 
====[[Paraquat Poisoning]]====
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====Diffuse alveolitis====
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====[[Diffuse Fibrosing Alveolitis|Diffuse alveolitis]]====
[[Image:Diffuse fibrosing alveolitis.jpg|right|thumb|150px|<small><center>Diffuse fibrosing alveolitis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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*Chronic disease of adult cattle occuring sporadically
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*Probably caused by repeated subclinical incidents of fog fever or farmer's lung
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*[[Extrinsic Allergic Bronchio-Alveolitis|'''Farmer's Lung''']]
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**Extrinsic allergic alveolitis
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**Hypersensitivity of ingested or inhaled moulds
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**May occur as an outbreak or sporadically in adult cattle
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*'''Hypersensitivity diseases''' often cause an lymphocytic interstitial pneumonia
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*Chronic interstitial pneumonia progresses to fibrosis
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**Sometimes called '''pneumonitis'''
         
[[Category:Pneumonia]]
 
[[Category:Pneumonia]]
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