Canker is an infection of the horn producing tissues of the foot. The infection begins in the frog. It can affect the sole, hoof wall, and bars of the foot as well. Although it most commonly affects draft breeds, any breed of horse can develop canker.

Rhodococcus equi is a bacteria that lives in the soil. It is an important cause of disease in foals between 3 weeks and 6 months of age.

Antibiotics are commonly used in horses for a variety of conditions. In order to determine which antibiotic is appropriate for a specific condition, a culture of the affected organ/ area needs to be performed.