Sequestrum

Meet ‘Ishink’. She is a yearling thoroughbred filly that sustained a severe wound to her hind leg when she was a foal. The wound exposed a large part of cannon bone and stripped the lining of the bone. This caused disruption to blood supply and a superficial piece of bone died which became a ‘sequestrum’. A bone sequestrum promotes infection and delays wound healing.

The wound will not heal until the sequestrum has been removed. X-Rays are used to diagnose the location and size of a sequestrum, but they will not be evident on X-rays until at least 2 weeks after the injury is sustained.

Ishink had her sequestrum diagnosed in February 2022, she underwent a general anaesthetic and surgery to remove the dead piece of bone and the abnormal infected tissue. Following surgery she had twice weekly bandage changes.

The area of the wound the wound was large, and despite the tissue being healthy, it still took 4 months for complete healing by ‘second intention’, which refers to wounds that must heal a large defect without being sutured.

Firstly granulation tissue is laid down, then new skin forms over the granulation tissue, as the wound edges contract.

Horses are prone to development of ‘proud flesh’ with such wounds, this can also delay wound healing as it prevents contraction and the growth of new skin cells over the tissue.

During Ishinks care the proud flesh was trimmed back to skin level as required, again to assist in promotion of healing.