Lumpy jaw refers to infection with swelling of the upper or lower jaw bones caused by the bacteria, Actinomyces bovis, a normal resident in the mouth. Establishment of infection may follow tooth eruption in maturing cattle or secondary to damage to the oral mucosa from coarse and prickly feeds.
Infection is accompanied by slow and progressive swelling of the affected area due to inflammation, necrosis and deposition of new bone. In time infection breaks out through sinuses in overlying skin, draining sticky pus with yellow gritty granules. Local lymph nodes are unaffected. The bony distortion interferes with chewing and weight gain.
Lumpy jaw is a sporadic disease affecting small numbers of animals. The disease may be difficult to detect until advanced and associated with obvious facial distortion or other clinical signs. Exclusion from the export process will require specific inspection of both sides of the head. Identifying affected animals is important in case they are rejected at destination.
Affected areas in the upper or lower jaw will be associated with a hard, immovable swelling. Discharging skin sinuses, drooling and weight loss may be present.
Laboratory confirmation in live animals requires smears of pus from deep within the lesion. Confirmation in dead animals should also include tissue sections in buffered formalin for histology.
Differential diagnoses include woody tongue, oral foreign bodies, jaw bone fracture, subcutaneous abscess and food impacted in the cheek recess behind broken teeth or missing teeth.
Lumpy jaw is difficult to treat successfully. In valuable animals with early lesions, extended treatment with ceftiofur, oxytetracyclines and/or sodium iodide may be attempted but results are uncertain and relapse may occur. Strong consideration should be given to salvage slaughter of affected animals before weight loss and the risk of condemnation occur.
The sporadic occurrence doesn't warrant special preventative measures. Awareness of the condition and systems for early detection and exclusion from the live export process are the main preventive strategies.