Why do horses get hoof abscesses and how are they treated?

Foot abscesses can be excruciating for horses in fact they can make the horse so lame that it can look like the horse has broken his leg! But why do they happen and what can be done about them?
Damage to the hoof capsule from a nail or a stone can allow bacteria to enter the hoof. This bacteria then gets trapped inside as the entrance closes up. Inflammatory cells build up inside this small pocket and with nowhere to go the pressure inside the foot increases making the foot extremely painful. The first thing you will notice is lameness with the foot also being warm to the touch and strong pulses being felt in the pastern area. 

Drainage drainage drainage
Sometimes an abscess will make its way out through a soft area of the foot such as at the heel bulbs or coronary band but often the abscess will need to be cut open to allow drainage relieving the pressure in the foot. The location of the abscess can be confirmed by your vet who will use an instrument called a hoof tester to press on the sole of the foot looking out for any sensitive areas. Once the vet is confident about the site of the abscess they will use a hoof knife to pare the sole of the foot away producing a dark smelly discharge. 
To encourage drainage of the abscess a wet poultice is placed on the foot for several days being changed daily to check for progress. Once the discharge has stopped the poultice can be removed but the hole may need to be covered to prevent further contamination from soil or bedding material. A course of antiinflammatories may be recommended to make your horse feel more comfortable but treatment with antibiotics is not necessary in most