Abscesses are usually caused by a bacterial infection which is localized at a certain point in the body. Dead white blood cells and bacterial matter create a build up of pus, which creates pressure. Abscesses in the hoof are especially painful, because the hoof capsule is a restricted environment – there’s little room for expansion, especially between the hoof wall and the coffin bone. To heal, abscesses need to break out to the surface of the body and drain, and they’ll follow the path of least resistance to get out. If an abscess isn’t able to break open and drain, the infection can become more widespread.
If your horse has a hoof abscess, your veterinarian is likely to recommend using a poultice to draw out infection. A poultice is a soft, moist mass that is applied to the hoof under a bandage, which can be purchased or homemade, using a variety of medicated, or natural ingredients.
Commercially-available products contain an anti-septic and a poulticing agent, such as tragacanth, a sap-like plant material, on a ready-to-use pad. You soak the pad in warm water, apply the poultice directly to the bottom of the foot, and bandage it in place. You can also use a homemade poultice such as a paste made from sugar and iodine or Betadine® solution. Sugar is osmotic, which means it will draw infection out. Iodine/Betadine® is added as a disinfectant. Another popular homemade poultice combines two parts wheat bran, one part Epsom salts and enough water to moisten the mixture.