Todayโs path rounds are on ๐ฅ๐ฎ๐ฆ๐ฉ๐ฒ ๐ฃ๐๐ฐ!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐ฎ๐ฆ๐ฉ๐ฒ ๐ฃ๐๐ฐ is probably one of the more descriptive veterinary disease names, being literally a disease causing a lumpy jaw! This is a type of ๐ฆ๐๐ง๐๐ข๐๐ฎ๐ฅ๐๐ซ ๐จ๐ฌ๐ญ๐๐จ๐ฆ๐ฒ๐๐ฅ๐ข๐ญ๐ข๐ฌ, or a bacterial infection of the mandibular bone.
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
Cattle get this disease! Other small ruminants like sheep and goats can probably get it too, but it is by far most common in cattle.
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
Lumpy jaw is caused by a bacteria called ๐๐๐ญ๐ข๐ง๐จ๐ฆ๐ฒ๐๐๐ฌ ๐๐จ๐ฏ๐ข๐ฌ. The bacteria normally lives in the mouth of cattle, and only becomes a problem when there is some kind of damage to the gums, lips or cheeks. One of the most common causes of oral tissue damage leading to this disease is rough or pokey material in the hay or pasture that the cattle are grazing, such as foxtail. The bacteria will enter the wound and cause an infection, that eventually works its way to the bone via the lymphatic vessels.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
Once in the bone, the bacteria forms a severe inflammatory reaction with accumulation of pus. In response to the infection, the bone begins to undergo ๐ซ๐๐ฌ๐จ๐ซ๐ฉ๐ญ๐ข๐จ๐ง (removal of bone) and ๐ฉ๐ซ๐จ๐ฅ๐ข๐๐๐ซ๐๐ญ๐ข๐จ๐ง (depositing new bone) at the same time. This leads to the mandible becoming enlarged, with the bone having a holey, Swiss cheese appearance due to the combined removal and deposition of bone. This can become so severe that the normal shape of the mandible is completely loss, and the animal can even begin to loose teeth or have them encompassed in the boney mass.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Most of the time this condition can be diagnosed based on appearance and clinical suspicion. If a veterinarian really wanted to confirm it, an X-ray would show the holey, poorly shaped mandible that is essentially ๐ฉ๐๐ญ๐ก๐จ๐ ๐ง๐จ๐ฆ๐จ๐ง๐ข๐ (not much else can cause that condition). The veterinarian can also take a sample of the tissue to look for the organism under the microscope.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐?
The treatment of choice is sodium iodide, given into the vein, repeated at 7-10 day intervals. This is fairly effective at killing the bacteria and stopping the growth of the lesion, however the mandible itself will never return to a normal shape or structure. If the animal is unable to eat properly or has other issues preventing it from having a good quality of life, it is often euthanized.
๐๐ก๐จ๐ญ๐จ๐ฌ
1-2) Some cross-sections of lumpy jaw cases with the tissue still present.
3-4) โBoiled outโ mandibles with no tissue remaining, showing the Swiss cheese appearance of the bone. 
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 1. Sixth Edition.
Photos 1-3 courtesy of University of Calgary Diagnostic Services Unit.
