Lumpy Jaw


Lumpy jaw is a disease of the jaw bone caused by a bacterial infection. The causative organism (Actinomyces bovis) of Lumpy jaw enters the soft tissue of the mouth through open wounds. These wounds can be created by foreign bodies (sticks, wire), plant awns, foxtail awns, or rough coarse feeds. The bacterium can be found in the mouths of healthy cattle.

Clinical signs

Lumpy jaw is a disease that produces permanent hard swellings on the jaw bones of cattle. Once an infection is established, bacterial by-products begin breaking down the bone. In response to the bone infection, the body tries to repair itself by creating new bone. This process creates honeycombed bone structures with tiny abscesses filled with pus. As the disease progresses, large cavities may open up, draining grainy pus. Because of the nature and location of the disease cattle may have difficulty eating and drinking. The animal often begins losing condition, and with time death may result.

Disease Transmission

In general, lumpy jaw is not considered highly contagious, but the bacteria can be spread from one animal to the next through infected saliva and draining pus that contaminates feed and water. The disease usually only affects one or two animals, but outbreaks can occur in herds being fed coarse, rough hay or on pastures with abrasive feeds.


Cases of lumpy jaw are often identified based on clinical signs alone. Microscopic examination of smears made from pus, along with cultures are the best ways to confirm this infection.


Infected animals are usually treated with intravenous administration of iodide compounds, such as sodium iodide. Follow-up treatments may be required at weekly intervals for several weeks. Tetracycline and penicillin are also commonly included in the treatment protocol. Administer them for 7-10 days. All feeding areas should be disinfected when possible. Surgical drainage of the affected areas may be necessary. Opened pockets must be flushed and packed with iodine for several days. Distorted bone may not return to its original shape even after curing the infection. Relapses of lumpy jaw are common.


There is no vaccine available for lumpy jaw. Not feeding coarse feed and properly treating and isolating infected animals are the best preventions.


For more information, or if you suspect any animal health related concerns, please contact the Chief Veterinary Office or call 204-945-7663 in Winnipeg.