A bone sequestrum is a portion of dead bone which generally occurs due to direct trauma to bone. Bone sequestrums are not very common and can be seen 2-3 weeks after injury.

How they do they occur?

Direct trauma damages cortical bone (outer layer of bone) which causes bone death due to loss of blood supply and bacterial infection.

What does it look like?

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The animal may show mild to moderate lameness. They are often non-healing wounds which can respond to antibiotics but recur once the antibiotic course ends. We often see pus coming from a small drain hole on the leg wound.

How is it diagnosed?

History of trauma, draining tracts and non-healing wounds.  We can also ultrasound or radiograph the leg to identify damaged bone.

- Radiograph: Abnormal bone circled.

- Ultrasound: Normal, smooth bone (white curve) is displayed on the left. Sequestrum is displayed on the right where the bone is interrupted (red arrow).

How do we treat this?

Surgery is required to remove the damaged portion of bone. Without surgery, the dead bone acts as foreign material causing a persistent source of irritation and infection

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