Difference between revisions of "Interstitial Pneumonia"

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Examples:
 
Examples:
====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'''
+
====[[Acute Bovine Pulmonary Emphysema and Oedema]]====
*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
 
*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
 
 
 
[[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]]====
  
  
====Diffuse alveolitis====
+
====[[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>]]
 
*Chronic disease of adult cattle occuring sporadically
 
*Probably caused by repeated subclinical incidents of fog fever or farmer's lung
 
*[[Extrinsic Allergic Bronchio-Alveolitis|'''Farmer's Lung''']]
 
**Extrinsic allergic alveolitis
 
**Hypersensitivity of ingested or inhaled moulds
 
**May occur as an outbreak or sporadically in adult cattle
 
 
 
*'''Hypersensitivity diseases''' often cause an lymphocytic interstitial pneumonia
 
*Chronic interstitial pneumonia progresses to fibrosis
 
**Sometimes called '''pneumonitis'''
 
  
  
 
[[Category:Pneumonia]]
 
[[Category:Pneumonia]]

Latest revision as of 18:13, 19 February 2011

Interstitial pneumonia (Image sourced from Bristol Biomed Image Archive with permission)
  • Lung inflammation that occurs primarily in alveolar walls rather than in alveolar spaces
  • Can be widely distributed but is often most severe in caudal lung lobes
  • Diffuse or patchy damage to alveolar septa, may be acute or chronic
  • Lesions in most cases result from blood-borne insult and are more likely to involve the dorsocaudal regions, although the damage is often diffuse
  • No concentrated inflammatory response in the airway, only secondary to damage of alveolar walls
  • As part of systemic infection
    • Canine distemper (in alveolar macrophages as inclusions)
    • Salmonellosis
    • Toxoplasmosis (in alveolar wall)
  • Acute interstitial pneumonia is characterised by exudation into the alveolar lumen and in cattle is associated with interstitial emphysema

Examples:

Acute Bovine Pulmonary Emphysema and Oedema

Paraquat Poisoning

Diffuse alveolitis