White line abscess, Sub Solar Abscess (pus-in-foot, PIF)
Cause: an infection developing between the hoof capsule and the sensitive laminae of the foot.
Signs: a rapidly progressive lameness (12-24 hours) to virtually non weight-bearing, normally in one foot only. Bounding digital pulses. Sensitivity to hoof testers over the affected area.
Treatment: paring of the affected hoof in order to release the pus, subsequent tubbing and/or poulticing.
Please watch the following video. It is a horse that presented with a severe right hind lameness associated with swelling around the fetlock. The foot was examined and pain was elicited when hoof testers were used to squeeze the inside area of the foot. The shoe was removed and the white line was pared out using a hoof knife. A black tract was followed and pus soon appeared. A larger hole was created to allow the pus to drain. Treatment involved tubbing the foot and poulticing the pared out area.
Cause: a progression of PIF when the pocket of pus erupts from the coronary band. Secondary infection of tissues within the hoof capsule.
Signs: similar to PIF but also soreness at the coronary band, occasionally pus.
Treatment: may require partial wall resection, occasionally under general anaesthetic, and debridement of infected structures.
The following video illustrates the appearance and treatment of a quittor case