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| − | ===Enzootic pneumonia of calves=== | + | ===[[Enzootic Pneumonia - Calves]]=== |
| − | [[Image:Acute suppurative pneumonia.jpg|right|thumb|100px|<small><center>Acute suppurative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]] | |
| − | [[Image:Calf pneumonia.jpg|right|thumb|100px|<small><center>Calf pneumonia - chronic, with abscesses, fibrosis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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| − | *Range of infectious agents together with managemental and environmental stress cause damage to the respiratory tract
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| − | *Causes unthriftiness in animals < 6 months old
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| − | *Usually the primary pathogen is a virus, secondary pathogens are bacteria and mycoplasmas
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| − | *Pathogens:
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| − | **[[:Category:Mycoplasmas|''Mycoplasmas'']]
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| − | ***Mycoplasmal [[Bronchi and Bronchioles Inflammatory - Pathology#Infectious causes of bronchitis or bronchiolitis|bronchitis]] and [[Lungs Inflammatory - Pathology#Infectious causes of pneumonia|pneumonia]] of calves is an important component of the syndrome of enzootic pneumonia
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| − | ***On its own causes Mycoplasmal ("Cuffing") pneumonia responsible for [[Bronchi and Bronchioles Inflammatory - Pathology#Infectious causes of bronchitis or bronchiolitis|bronchitis and bronchiolitis]] and [[Lungs Inflammatory - Pathology#Infectious causes of pneumonia|bronchointerstitial pneumonia]]
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| − | ***It is thought to pick up host antigens in order to prevent recognition by the body defences as foreign
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| − | ***In uncomplicated mycoplasma infection, the lesions are generally mild and consist of patchy red/purple areas of [[Lungs Ventilation - Pathology#Atelectasis|atelectasis]] in the '''cranio-ventral lung lobes'''
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| − | ***More confluent areas can develop with an underlying bronchointestitial pneumonia and resulting atelectasis
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| − | ***''M. bovis''
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| − | ****Most pathogenic
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| − | ****Widespread lymphofollicular accumulations which contain germinal centres develop more slowly
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| − | ****These lesions can result in narrowing of the bronchiolar lumina - this is the classical lesion of '''‘cuffing pneumonia’'''
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| − | ***''M. dispar''
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| − | ***''Ureaplasma'' sp.
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| − | **Viruses
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| − | ***[[Respiratory Viral Infections - Pathology#Respiratory syncytial virus|Bovine respiratory syncytial virus (BRSV)]] - can be primary, causes suppression of pulmonary immune response
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| − | ***[[Respiratory Viral Infections - Pathology#Parainfluenza- 3|Parainfluenza- 3 (PI3)]] - can be primary, causes suppression of pulmonary immune response
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| − | ***[[Flaviviridae|Bovine viral diarrhoea virus (BVDV)]] - suppression of pulmonary immune response
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| − | ***[[Adenoviridae|Adenoviruses]]
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| − | ***[[Coronaviridae|Calf coronavirus]]
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| − | ***[[Respiratory Viral Infections - Pathology#Infectious bovine rhinotracheitis (IBR)|Bovine herpes viruses]]
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| − | **Bacteria
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| − | ***[[Mannheimia haemolytica|''Manheimia (Pasteurella) haemolytica'' serotype A1]]
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| − | ***[[Pasteurella multocida|''Pasteurella multocida'']]
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| − | ***[[Arcanobacter pyogenes|''Arcanobacter pyogenes'']]
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| − | ***''[[Haemophilus somnus]]''
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| − | *All transmitted by aerosol and direct contact
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| − | *Gross pathology:
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| − | **Consolidation of the cranioventral areas which increases in volume with duration
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| − | **On cut surface, exudate in the main airway of affected lobules with thickening of the surrounding connective tissue
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| − | *Micro pathology:
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| − | **Substantial lymphoid tissue around the airways
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| − | **Even to proper follicle formation, some of which may be large enough to compress the lumen
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| − | **Mixed cell exudate in the airway lumen
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| − | **Partial alveolar collapse distal to the compression
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| − | **Alveolar exudate contains a mixture of inflammatory cells
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| − | **Slight thickening of the alveolar walls with lymphocytes
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| | ===Acute exudative pneumonia=== | | ===Acute exudative pneumonia=== |