Bubba is a 2 year old small crossbreed who presented to us with a history of lameness in the left forelimb for a period of 2 weeks. According to the the owner, the lameness was intermittent and seemed about the same intensity for the two week period. From the history, there was no known incident oftrauma to the leg or any excessive exercise, which might have brought on the lameness.
On physical exam, the dog was painful in the region of the elbow. At this point, our rule-outs included a joint injury such as a sprain or strain of ligaments, or partial fracture of the bone. In order to find out what was wrong, we sedated Bubba and took radiographs of the limb. On inspection of the radiographs, we noted an area below the elbow where the bone looks as if it is eaten away. Note the hole in the images below:
The possible causes of this type of lesion include: bone cyst, bone tumor, or bone infection with either bacteria or fungus. Typically, tumors tend to eat away the bone and have more dramatic changes in the bone. Infections also tend to leave a bone which looks more “angry” as the bone responds to the infection.
Because bone tumors often spread to the lungs (metastasize), we took pre-operative radiographs of the lungs to look for tumors. Fortunately, the lungs were normal and thus we moved on towards getting our diagnosis.
In order to distinguish exactly what was going on in the leg, we took Bubba to surgery and took a core biopsy out of the lesion. These radiographs show the bone after the biopsy.
Bubba recovered from anesthesia without incident and we stabilized the leg for 2 weeks with a splint to support the bone as it heals from the surgery.
The biopsy specimen was sent to the lab for analysis. Typically bone specimens take up to 1 week to be analyzed because the calcium has to be leeched out of the bone so it can be sliced and prepared for the pathologists. When we received the results, we were pleased and somewhat surprised to find out that this was a benign lesion which probably arose from prior trauma to the area. The trauma may have injured the blood supply to that area of the bone and/or the bone cells themselves so they were unable to create solid bone.
Removing the injured tissue has reduced the lameness and Bubba is recovering nicely.