Difference between revisions of "Enzootic Pneumonia - Calves"

Revision as of 13:13, 20 July 2010

Acute suppurative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)

Calf pneumonia - chronic, with abscesses, fibrosis (Image sourced from Bristol Biomed Image Archive with permission)

Range of infectious agents together with managemental and environmental stress cause damage to the respiratory tract
Causes unthriftiness in animals < 6 months old
Usually the primary pathogen is a virus, secondary pathogens are bacteria and mycoplasmas
Pathogens:
- Mycoplasmas
  - Mycoplasmal bronchitis and pneumonia of calves is an important component of the syndrome of enzootic pneumonia
  - On its own causes Mycoplasmal ("Cuffing") pneumonia responsible for bronchitis and bronchiolitis and bronchointerstitial pneumonia
  - It is thought to pick up host antigens in order to prevent recognition by the body defences as foreign
  - In uncomplicated mycoplasma infection, the lesions are generally mild and consist of patchy red/purple areas of atelectasis in the cranio-ventral lung lobes
  - More confluent areas can develop with an underlying bronchointestitial pneumonia and resulting atelectasis
  - M. bovis
    - Most pathogenic
    - Widespread lymphofollicular accumulations which contain germinal centres develop more slowly
    - These lesions can result in narrowing of the bronchiolar lumina - this is the classical lesion of ‘cuffing pneumonia’
  - M. dispar
  - Ureaplasma sp.
- Viruses
  - Bovine respiratory syncytial virus (BRSV) - can be primary, causes suppression of pulmonary immune response
  - Parainfluenza- 3 (PI3) - can be primary, causes suppression of pulmonary immune response
  - Bovine viral diarrhoea virus (BVDV) - suppression of pulmonary immune response
  - Adenoviruses
  - Calf coronavirus
  - Bovine herpes viruses
- Bacteria
All transmitted by aerosol and direct contact
Gross pathology:
- Consolidation of the cranioventral areas which increases in volume with duration
- On cut surface, exudate in the main airway of affected lobules with thickening of the surrounding connective tissue
Micro pathology:
- Substantial lymphoid tissue around the airways
- Even to proper follicle formation, some of which may be large enough to compress the lumen
- Mixed cell exudate in the airway lumen
- Partial alveolar collapse distal to the compression
- Alveolar exudate contains a mixture of inflammatory cells
- Slight thickening of the alveolar walls with lymphocytes

@@ Line 1: / Line 1: @@
-==Introduction==
+[[Image:Acute suppurative pneumonia.jpg|right|thumb|100px|<small><center>Acute suppurative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
-A pneumonic disease which is caused by a range of infectious agents in combination with management and environmental stress causing damage to the respiratory tract predisposing to disease.
+[[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>]]
-It is principally of viral origin and the following viruses have been implemented in disease. [[Bovine Respiratory Syncytial Virus|Bovine respiratory syncytial virus (BRSV)]], [[Bovine Parainfluenza - 3|Parainfluenza- 3 (PI3)]], [[Bovine Viral Diarrhoea Virus|Bovine viral diarrhoea virus (BVDV)]], [[Bovine Adenovirus|Adenoviruses]], [[Bovine Coronavirus|Calf coronavirus]] and [[Infectious Bovine Rhinotracheitis|Bovine herpes viruses]].
-[[Mycoplasmas]] have also been implemented and secondary bacterial infection is common.
-Bacterial agents include [[Mannheimia haemolytica|''Manheimia (Pasteurella) haemolytica'' serotype A1]], [[Pasteurella multocida|''Pasteurella multocida'']], [[Arcanobacter pyogenes|''Arcanobacter pyogenes'']]  and ''[[Haemophilus somnus]]''.
-All agents are transmitted by aerosol and direct contact.
-==Signalment==
+*Range of infectious agents together with managemental and environmental stress cause damage to the respiratory tract
-Mainly a problem in calves less than 6 months old and particularly affects 2-10 week old animals. It occurs more commonly in dairy calves than beef calves.
+*Causes unthriftiness in animals < 6 months old
+*Usually the primary pathogen is a virus, secondary pathogens are bacteria and mycoplasmas
-==Diagnosis==
+*Pathogens:
+**[[:Category:Mycoplasmas|''Mycoplasmas'']]
-To establish the cause nasopharangeal swabs or broncho-alveolar lavage can be undertaken and examined for bacteria, viruses or mycoplasma.
+***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
+***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]]
-Fluorescent antibody tests can be used to detect viral causes. Paired serum samples will also show recent exposure to a viral pathogen. Additionally Post mortem exam can confirm the presence of certain pathogens.
+***It is thought to pick up host antigens in order to prevent recognition by the body defences as foreign
+***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'''
-==History and Clinical signs==
+***More confluent areas can develop with an underlying bronchointestitial pneumonia and resulting atelectasis
-<u>Acutely affected animals:</u>
+***''M. bovis''
+****Most pathogenic
-Affects a group of calves who display respiratory signs including a dry cough, increased respiratory rate, nasal  and lacrimal discharge. Animals are pyrexic, depressed and also often anorexic.
+****Widespread lymphofollicular accumulations which contain germinal centres develop more slowly
+****These lesions can result in narrowing of the bronchiolar lumina - this is the classical lesion of '''‘cuffing pneumonia’'''
-<u>Chronically affected animals:</u>
+***''M. dispar''
+***''Ureaplasma'' sp.
-Usually affects a group of animals who are kept indoors. The disease is gradual in onset and although respiratory signs similar to acutely affected animals are present the animals remain bright and eating.
+**Viruses
+***[[Bovine Respiratory Syncytial Virus|Bovine respiratory syncytial virus (BRSV)]] - can be primary, causes suppression of pulmonary immune response
-==Pathology==
+***[[Bovine Parainfluenza - 3|Parainfluenza- 3 (PI3)]] - can be primary, causes suppression of pulmonary immune response
-[[Image:Acute suppurative pneumonia.jpg|right|thumb|200px|<small><center>Acute suppurative pneumonia (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
+***[[Flaviviridae|Bovine viral diarrhoea virus (BVDV)]] - suppression of pulmonary immune response
-[[Image:Calf pneumonia.jpg|right|thumb|200px|<small><center>Calf pneumonia - chronic, with abscesses, fibrosis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
+***[[Adenoviridae|Adenoviruses]]
+***[[Coronaviridae|Calf coronavirus]]
-'''Gross pathology''':
+***[[Infectious Bovine Rhinotracheitis|Bovine herpes viruses]]
+**Bacteria
-Consolidation of the cranioventral lung areas  will be present which increases in volume with duration of disease. Exudate is present in the main airway of affected lung lobules with thickening of the surrounding connective tissue.
+***[[Mannheimia haemolytica|''Manheimia (Pasteurella) haemolytica'' serotype A1]]
+***[[Pasteurella multocida|''Pasteurella multocida'']]
-'''Micro pathology''':
+***[[Arcanobacter pyogenes|''Arcanobacter pyogenes'']]
+***''[[Haemophilus somnus]]''
-Even though proper follicle formation is present, some of which may be large enough to compress the lumen.
+*All transmitted by aerosol and direct contact
-A mixed cell exudate will be present in the airway lumen and substantial lymphoid tissue will be present around the airways. The alveolar walls may be thickened with [[Lymphocytes - Introduction|lymphocytes]].
+*Gross pathology:
+**Consolidation of the cranioventral areas which increases in volume with duration
-==Treatment and Control==
+**On cut surface, exudate in the main airway of affected lobules with thickening of the surrounding connective tissue
-Once a diagnosis has been made as to the likely causative organisms a number of management issues on the farm must be addressed. These include ensuring each calf ingests enough good quality colostrum, good nutrition, stress management, good housing, and other management of any concurrent diseases. Additionally group sizes should be assessed and ideally no more than 20 calves should be housed per group. Animals should be kept in groups of the same age and should not share airspace with adult cattle.  If this is not possible animals should be arranged with the air flowing from youngest to oldest. Isolation/ hospital pens should be available to prevent spread of disease and to ensure affected animals are cared for correctly.
+*Micro pathology:
-Additionally, once causative organisms have been identified [[Vaccines|vaccination]] programmes can also be put in place for cows 4 weeks pre-partum to improve colostral antibodies that the calves will receive.
+**Substantial lymphoid tissue around the airways
+**Even to proper follicle formation, some of which may be large enough to compress the lumen
-==Prognosis==
+**Mixed cell exudate in the airway lumen
-Good if recognised early and if affected animals are treated and management is improved.
+**Partial alveolar collapse distal to the compression
+**Alveolar exudate contains a mixture of inflammatory cells
-==Literature Search==
+**Slight thickening of the alveolar walls with lymphocytes[[Category:Cattle]][[Category:To_Do_-_Clinical]]
-[[File:CABI logo.jpg|left|90px]]
-Use these links to find recent scientific publications via CAB Abstracts (log in required unless accessing from a subscribing organisation).
-<br><br><br>
-[http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=%22Enzootic+Pneumonia%22&occuring1=title&rowId=2&options2=AND&q2=cattle&occuring2=od&rowId=3&options3=AND&q3=&occuring3=freetext&x=40&y=17&publishedstart=yyyy&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all Enzootic pneumonia of calves publications]
-==References==
-Andrews, A.H, Blowey, R.W, Boyd, H and Eddy, R.G. (2004) '''Bovine Medicine''' (Second edition), ''Blackwell Publishing''
-Merck & Co (2008) '''The Merck Veterinary Manual''' (Eighth Edition) ''Merial ''
-{{review}}
-[[Category:Respiratory Diseases - Cattle]]
 [[Category:Respiratory_Bacterial_Infections]]
-[[Category:Brian Aldridge reviewing]]

Difference between revisions of "Enzootic Pneumonia - Calves"

Revision as of 13:13, 20 July 2010

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