Fractured Tail Bone in a Horse

A seven year-old gelding presented for a history of recent trauma via a pasture mate over the region of the tail head. The gelding was able to move his tail however there was firm swelling around the region and he was tender to palpation (Figure 1 and 2). Physical exam performed 2 weeks after the injury was first noted revealed moderate swelling yet no pain on palpation. In addition, the tail had a normal range of motion and there was normal tail anal tone.
.

Figure 1

Figure 2

A radiographic exam was performed and a mildly displaced fracture of the first coccygeal bone was identified. In Figure 3, the vertebrae in the center of the image has what appears to be a cap on the spinous process which represents the mildly displaced fracture. In Figure 4, the coccygeal vertebrae in question is magnified and the fractured bone is highlighted with the red arrows. The yellow arrow in Figure 4 identifies the fracture line through the spinous process of the first coccygeal vertebrae.

Figure 3

Figure 4

The fracture will heal with time and there should not be any negative, long term effects from this injury. However, there remains a concern of the development of a sequestrum (de-vitalized bone) at the fracture site. A sequestrum would develop if the fracture resulted in loss of blood supply to the fractured fragment. This would result in the likely development of a draining fistula as the body attempts to reject the sequestrum. The gelding will be given several weeks of rest and relaxation before returning to light riding. A follow-up radiographic exam will be performed in 2-4 months.