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'''Lumpy jaw''' is a chronic infectious condition which affects cattle. It is caused by the anaerobic filamentous bacteria [[Actinomyces bovis|''Actinomyces bovis'']]  

'''Lumpy jaw''' is a chronic infectious condition which affects cattle. It is caused by the anaerobic filamentous bacteria [[Actinomyces bovis|''Actinomyces bovis'']]  

Actinomyces is a normal commensal of the oral cavity, upper respiratory tract and digestive tract of cattle, it gains entry to underlying soft tissues when the mucosa is damaged by trauma or eruption of teeth. It causes an inflammatory reaction, the connective tissue proliferates and is followed by infiltration of leukocytes which results in the formation of a walled off granuloma. The granuloma invades the bones of the head, in particular the mandible, and continues to grow in size.

Actinomyces is a normal commensal of the oral cavity, upper respiratory tract and digestive tract of cattle, it gains entry to underlying soft tissues when the mucosa is damaged by trauma or eruption of teeth. It causes an inflammatory reaction, the connective tissue proliferates and is followed by infiltration of leukocytes which results in the formation of a walled off granuloma. The granuloma invades the bones of the head, in particular the mandible, and continues to grow in size.

Lesions are charcterised by gross swelling, abscesses and draining fistulae overlying granulation of the madible and maxila. In some cases the [[Oesophagus - Anatomy & Physiology|oesophagus]] and [[Oesophageal groove|oesophageal groove]] may become involoved but the lymph nodes are not affected.

Lesions are characterised by gross swelling, abscesses and draining fistulae overlying granulation of the mandible and maxilla. In some cases the [[Oesophagus - Anatomy & Physiology|oesophagus]] and [[Oesophageal groove|oesophageal groove]] may become involved but the lymph nodes are not affected.

==Signalment==

==Signalment==

The condition affects cattle''' 2-5 yrs''' old. It is found worldwide but is most prevelent in Western and mid-western states of the USA.

The condition affects cattle''' 2-5 yrs''' old. It is found worldwide but is most prevalent in Western and mid-western states of the USA.

==Diagnosis==

==Diagnosis==

The condition is easily diagnosed on clinical signs and can be confirmed by crushing and staining the yellow granules expressed with the pus from skin leisions to reveal '''gram-positive filamentous rods'''.   

The condition is easily diagnosed on clinical signs and can be confirmed by crushing and staining the yellow granules expressed with the pus from skin lesions to reveal '''gram-positive filamentous rods'''.   

    

    

===Clinical signs===

===Clinical signs===

*Facial distortment

*Facial distortment

*Granuloma formation overlying the mandible and maxila

*Granuloma formation overlying the mandible and maxilla

*Fistulae draining small amounts of thick pus with yellow granules

*Fistulae draining small amounts of thick pus with yellow granules

*Difficulties with mastication

*Difficulties with mastication

==Prognosis==

==Prognosis==

Treatment is rarely successful in advanced cases and recurrence of leisions is common; slaughter is advised.   

Treatment is rarely successful in advanced cases and recurrence of lesions is common; slaughter is advised.   

==References==

==References==