Foot abscesses are quite common when there is environmental change such as wet and muddy conditions after a dry summer. Recurrence can also indicate a weakened immune system.
Grit or soil can enter the hoof or sole through a small fissure, or via the ‘white line’ (where the sole and hoof meet). The foreign body becomes trapped and causes an inflammatory response, leading to infection and consequent abscess formation.
All abscesses must be drained out by careful trimming into the hoof. This requires localisation (by using hoof testers), and usually involves removal of the shoe. The vet or farrier will use a knife to pare and relieve the pressure and establish drainage. Assuming the horse has had tetanus prophylaxis, management will then be by hot tubbing and poulticing. Your farrier should be consulted about the best management of the situation.
Establishing drainage is a far more potent analgesic than giving painkillers such as ‘Bute’ or NSAIDs. Antibiotics are rarely appropriate. After a few days of hot tubbing and poulticing the horse should rapidly become sound. The foot can then be hardened off by dry dressing, exposure to air and perhaps the use of an astringent such as formalin or iodine.
Ideally the horse should be box rested in a dry environment whilst lame. If turned out, e.g. with a boot or tape bandage, the favouring of one leg can lead to injury of the `good’ leg. If the horse does not become sound after 5 days or so, or if the abscess recurs, the vet should be consulted. It may be necessary to x-ray with special packing to see the extent of the abscess. The `hole’ may need to be packed (e.g. with hoof putty or Stockholm tar/cottonwool plug) and the foot may need to be re-shod with a pad to protect the area.
Once dressings have been completed and the shoe is back on, the horse can then be turned out or resume work almost straight away.