View source for Acute Bovine Pulmonary Emphysema and Oedema

====Acute bovine pulmonary emphysema and oedema (ABPEE)====
[[Image:Fog fever 1.jpg|right|thumb|150px|<small><center>Fog fever (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
[[Image:Fog fever 2.jpg|right|thumb|150px|<small><center>Fog fever (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
[[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>]]

*Synonym: '''fog fever'''
*Usually seen in adult beef cattle in the autumn as an outbreak
*Associated with a change in pasture (from dry to lush, green)
*Severe respiratory distress with laboured breathing and grunting on expiration
*Causes [[Interstitial Pneumonia]]
*Can result in [[Diffuse Fibrosing Alveolitis|diffuse fibrosing alveolitis]]
*Gross appearance is that of enlarged wet lungs, the interlobular septa are markedly widenedith [[Pulmonary Oedema|oedema]] and [[Pulmonary Emphysema|emphysema]]
*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
*Their loss allows massive flooding of the alveoli with a protein-rich fluid
*The sequence of events in the lung is as follows:
**Alveolar flooding with a protein-rich fluid due to the necrosis of Type 1 epithelium
**As the incoming air dries this fluid, fibrinous 'hyaline membranes' form
**Proliferation of the more resistant cuboidal Type 2 epithelium which line the alveoli, called 'epithelialisation'
**Then either there is
***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
**Or
***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
*Sequel
**Residual scarring if animal survives initial onslaught
**In chronic exposures there may be extensive fibroplasia

*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


[[Category:Respiratory Diseases - Cattle]]
[[Category:Pneumonia]]
[[Category:To Do - Respiratory]][[Category:To Do - Major]]