Q: How do you locate an abscess in a hoof?
A: A hoof abscess is a localised accumulation of purulent fluid (pus) within the horse’s hoof. The pus is produced as a reaction by the horse’s body to infection. A hoof abscess generally causes sudden-onset, severe lameness. Despite the dramatic onset and severity of the lameness associated with a hoof abscess, it is thankfully usually relatively quick and easy to treat and in most cases does not result in any long-term issues. However, if left untreated or complicated by other issues hoof abscesses can cause damage to the internal structures of the hoof itself.
Apart from the sudden lameness, an owner may also notice swelling of the coronary band above the hoof, heat coming from the hoof, heat generally in the limb, a low-grade fever, draining tracts from the abscesses (pus, often grey or black in colour seen at the sole/coronary band), an increased digital pulse and evidence of the hoof-injury that has led to the introduction of the bacteria. If an abscess is left untreated or is situated deep within the hoof, you can sometimes see bone erosion on x-rays secondary to the destructive nature of the infection.
Vets generally begin by feeling for the digital pulse in that limb. If this is palpable and they have strong suspicions that the cause is an abscess, the first step is usually to remove the shoe (if shod) and clean the foot. Hoof testers are then used focally to find the area in which the abscess is situated. When the foot is examined or trimmed, a black spot may be visible on the sole or sole-wall junction. This black spot is the tract through which the abscess is draining. The original crack or puncture wound that caused the infection in the first place is also often seen. This can all help lead your vet to the precise location of the abscess itself.