Difference between revisions of "Calf Diphtheria"

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*Caused by Fusiformis.
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Also known as: '''''Necrobacillosis'''''
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==Fibrinous/Diptheritic Inflammation==
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*Severe damage to epithelium produces exudation of fibrin - with formation of dry white fibrinous deposit - diptheritic membrane.
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*Usually associated with organism ''[[Fusobacterium necrophorum]]'' found everywhere in environment (but strict anaerobe).
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*Produces lesions that damage epithelium due to toxin that damages vessels.
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*Often a secondary invader but can be a primary pathogen.
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====Clinical====
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*Seen in animals kept in cold, damp, muddy conditions.
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*Usually associated with poor general health.
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*Animals usually less than 6 months old, in groups and poorly kept.
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*Lesions affect [[Tongue - Anatomy & Physiology|tongue]], inside of mouth and [[Larynx - Anatomy & Physiology|larynx]]. 
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*Usually die fairly acutely as exudate blocks airway. 
  
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== Introduction ==
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*May occur in young lambs secondary to [[orf]] (parapox) virus infection that can spread from [[Lips|lips]] to the inside of the mouth.
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::(These lesions then become secondarily infected with Fusiformis.)
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*Involvement of the [[Pharynx - Anatomy & Physiology|pharynx]] and [[Larynx - Anatomy & Physiology|larynx]] may result in dyspnoea and the development of pneumonia.
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*May lead to death.
  
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This is a disease associated with ''[[Fusobacterium necrophorum]]'', which is a strict anaerobic bacteria found everywhere in the environment. The disease is usually trasmitted by oral ingestion of the bacteria. It is often a secondary invader, meaning prior tissue damage must have to occur for the bacteria to gain entry, however it can be a primary pathogen in some cases. There are two forms of calf diptheria; oral and laryngeal.
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=====Macroscopically=====
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*Grossly, there is a firm swelling visible on the outer aspect of the [[Cheeks|cheek]]
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*On the mucosal surface there is a deep, irregular ulcer, covered by a thick diphtheritic membrane.
  
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'''Oral form''' - common yet sporadic in occurrence and is often associated with poor hygiene especially in housed calves that are bucket fed, although it can occur in calves at pasture. Calves are usually less than three months old and the disease is often predisposed to by teeth eruption, rough feed, poor use of dosing gun or presence of a concurrent disease.
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=====Microscopically=====
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*There is complete loss of the surface epithelium:
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**a mass of necrotic debris
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**polymorphs and fibrin is found overlying severely inflamed subepithelial tissues in which bacterial colonies may be seen and around which there may be marked fibrosis in an attempt to “wall off” the lesion.
  
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'''Laryngeal form '''- is less common can be seen in animals of all ages, but particularly calves up to the age of one year.
 
  
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[[Image:Necrotising laryngitis.jpg|right|thumb|100px|<small><center>Necrotising laryngitis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
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[[Image:Tracheitis in calf diphtheria.jpg|right|thumb|100px|<small><center>Tracheitis in calf diphtheria (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]
  
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== Clinical Signs ==
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*Synonyms: '''laryngeal diphtheria, calf diphtheria'''
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*Common disease in cattle, and can occur in swine
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*Caused by infection with [[Fusobacterium necrophorum|''Fusobacterium necrophorum'']] 
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*Lesions may also be found in other parts of the [[Pharyngitis|oropharynx]] 
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*The bacterium usually gains entry through damaged mucosal surfaces e.g. after viral infections or injury following (poor!) use of dosing guns, coarse poor quality roughage
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*Results in severe acute neutrophilic [[Larynx Inflammatory - Pathology#Infectious causes of laryngitis|laryngitis]]
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*Extensive accumulation of fibrin and necrotic cellular debris on the ulcerated mucosal surface
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*Lesions appear as dry plaques of fibrinonecrotic exudate and ulceration on the laryngeal mucosa
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*Inhalation of exudate and bacterial organisms may cause [[Bronchi and Bronchioles Inflammatory - Pathology#Infectious causes of bronchitis or bronchiolitis|broncho]][[Lungs Inflammatory - Pathology#Infectious causes of pneumonia|pneumonia]]
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*Death may result from toxaemia or asphyxiation
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*Also may occur in pigs
  
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Swelling of the rostral cheek and salivation are the main clinical signs.
 
  
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Upon physical examination, there may be a foul smell emitting from the mouth and deep necrotic lesions may be found on the cheek or tongue. These irregular shaped ulcers will be covered by a thick, diphtheritic membrane. In severe cases, sloughing of the tongue may occur.
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[[Category:Tongue_-_Pathology]][[Category:Oral Diseases - Cattle]][[Category:Respiratory Diseases - Cattle]][[Category:To_Do_-_Clinical]]
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[[Category:Oral Diseases - Pig]][[Category:Oral Diseases - Sheep]]
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If the larynx or pharynx are involved, swelling may lead to dyspnoea and the presence of pneumonia. These animals will also be pyrexic. They usually die fairly quickly as exudate may block the airways.
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[[Category:Respiratory_Bacterial_Infections]]
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== Diagnosis ==
 
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Unhygienic housing conditions, poor general health, along with clinical signs and signalment of the animal are indicative of the disease.
 
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Thorough oral examination with a gag is required for a definitive diagnosis. Differential diagnoses may include [[Foot and Mouth Disease|Foot and Mouth Disease Virus]], foreign bodies, [[Bovine Papular Stomatitis|Papular Stomatitis]] and [[BVDV|BVD mucosal disease]]. Appearance of the lesions should exclude all of the above differentials.
 
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== Treatment and Control ==
 
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The animal should be isolated from the herd and cross contamination between its and others' feed buckets and equipment should be prevented.
 
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Treatment with anaerobic specific [[antibiotics]] should commence immediately, either parenterally or orally for three to five days. In the laryngeal form, treatment should continue for longer.
 
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Control focuses on hygiene with recommendation to disinfect all feed buckets regularly and improve the quality of feed.
 
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{{review}}
 
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{{OpenPages}}
 
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[[Category:Tongue_-_Pathology]] [[Category:Oral_Diseases_-_Cattle]] [[Category:Respiratory_Diseases_-_Cattle]] [[Category:Expert_Review - Farm Animal]] [[Category:Oral_Diseases_-_Pig]] [[Category:Oral_Diseases_-_Sheep]] [[Category:Respiratory_Bacterial_Infections]]
 

Revision as of 17:06, 17 February 2011

  • Caused by Fusiformis.

Fibrinous/Diptheritic Inflammation

  • Severe damage to epithelium produces exudation of fibrin - with formation of dry white fibrinous deposit - diptheritic membrane.
  • Usually associated with organism Fusobacterium necrophorum found everywhere in environment (but strict anaerobe).
  • Produces lesions that damage epithelium due to toxin that damages vessels.
  • Often a secondary invader but can be a primary pathogen.

Clinical

  • Seen in animals kept in cold, damp, muddy conditions.
  • Usually associated with poor general health.
  • Animals usually less than 6 months old, in groups and poorly kept.
  • Lesions affect tongue, inside of mouth and larynx.
  • Usually die fairly acutely as exudate blocks airway.
  • May occur in young lambs secondary to orf (parapox) virus infection that can spread from lips to the inside of the mouth.
(These lesions then become secondarily infected with Fusiformis.)
  • Involvement of the pharynx and larynx may result in dyspnoea and the development of pneumonia.
  • May lead to death.
Macroscopically
  • Grossly, there is a firm swelling visible on the outer aspect of the cheek
  • On the mucosal surface there is a deep, irregular ulcer, covered by a thick diphtheritic membrane.
Microscopically
  • There is complete loss of the surface epithelium:
    • a mass of necrotic debris
    • polymorphs and fibrin is found overlying severely inflamed subepithelial tissues in which bacterial colonies may be seen and around which there may be marked fibrosis in an attempt to “wall off” the lesion.


Necrotising laryngitis (Image sourced from Bristol Biomed Image Archive with permission)
Tracheitis in calf diphtheria (Image sourced from Bristol Biomed Image Archive with permission)
  • Synonyms: laryngeal diphtheria, calf diphtheria
  • Common disease in cattle, and can occur in swine
  • Caused by infection with Fusobacterium necrophorum
  • Lesions may also be found in other parts of the oropharynx
  • The bacterium usually gains entry through damaged mucosal surfaces e.g. after viral infections or injury following (poor!) use of dosing guns, coarse poor quality roughage
  • Results in severe acute neutrophilic laryngitis
  • Extensive accumulation of fibrin and necrotic cellular debris on the ulcerated mucosal surface
  • Lesions appear as dry plaques of fibrinonecrotic exudate and ulceration on the laryngeal mucosa
  • Inhalation of exudate and bacterial organisms may cause bronchopneumonia
  • Death may result from toxaemia or asphyxiation
  • Also may occur in pigs
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