Lumpy Jaw
Causative Agent
  • Lumpy jaw is the result of an infection of the jawbone with the bacteria, Actinomyces bovis.
  • A. bovis is normally found in the mouths of healthy animals.
  • Bacteria may enter small wounds in the mouth, caused by tooth eruption or by coarse feed.
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Lumpy Jaw
Swelling of the jaw bone subsequent to bacterial infection causes the formation of conspicuous "lumps".
Geographic and Seasonality:
  • Can occur throughout the year and throughout BC.
Hosts, Transmission and Life Cycle
  • Occasionally found in wild ungulates such as white-tailed deer (Odocoileus virginianus), mule deer (O. hemionus), moose (Alces alces), caribou (Rangifer tarandus) and mountain sheep (Ovis canadensis).
  • This disease does not normally spread from animal to animal, but draining wounds can spread bacteria on common feed sources.
Signs and Symptoms
  • Once bacterial infection is established, bacterial by-products break down existing bone and promote the growth of new bone; consequently, affected areas of the jaw expand forming lumps or thickened areas of bone, honeycombed with tiny abscesses.
  • Tissues within the mouth may become swollen and there can be spread to nearby areas of the mouth.
  • Difficulty chewing.
  • Tooth loss and impaction of feed usually occurs in affected areas.
  • Other than lesions in the mouth, animals may appear healthy but are often thin since jaw lesions may interfere with the ability to eat.
Meat Edible?
  • Affected areas of the jaw should not be consumed; otherwise, the rest of the carcass is suitable for human consumption.
Human Health Concerns and Risk Reduction
  • Although lumpy jaw cannot be contracted from animals, care should be taken not to cut into the swellings of the jaw as pus can spread and contaminate other parts of the carcass.
Samples for Diagnosis
  • Lower jaw and surrounding tissue.
Further Reading
  • Alaska Department of Fish and Game Lumpy Jaw
  • Wobeser G. 2001. Actinomyces and Arcanobacterium infections. Pp. 487-488 in E.S. Williams, I.K. Barker (eds.), Infectious Diseases of Wild Mammals. 3rd Ed. Iowa State University Press. Ames, IA.
  • Elkin B., Zamke R.L. 2001. Common Wildlife Diseases and Parasites in Alaska. Alaska Department of Fish and Game. Anchorage, AK.
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