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AFA CERTIFIED FARRIER, ROOD & RIDDLE EQUINE HOSPITAL The equine hoof is a unique struc- ment is to remove all of the dead/infected tissue and begin Thrush is a term used to describe an infection of the frog of the foot by keratolytic bacteria. Fusobacterium necrophorum is a gram-negative obligate anaerobic bacillus that has been associated with this type of infection. Thrush usually presents as foul smelling black matter in the sulci of the frog.
Thrush commonly occurs as a result of poor environmental con- ditions but may occur in horses that are well kept. If the hoof has abnormalities such as excessive length, contracted heels, or shod with a full pad thrush may be more likely to develop.
Horses may have thrush but not show lameness until the sensi- tive structures are involved. To eliminate thrush it is important is more likely to develop an abscess or “white line disease” to provide a clean environment and give the hoof a balanced because the bacteria and fungi are able to invade the abnormal trim to remove the necrotic tissue. Chlorine dioxide is a com- hoof involved. Infections of deep structures such as the coffin bone, coffin joint, navicular bone/bursa, digital tendon sheath, Canker is an uncommon infection seen in poor environ- or collateral cartilages carry a more guarded prognosis than mental conditions and usually associated with draft breeds.
infection of superficial structures.
Canker is a gram-negative bacterial infection that affects the frog Early identification of hoof infections can greatly and heel bulbs. The characteristic yellow-white tissue covering improve the case outcome. Recognition of lameness and a good the frog and heel bulbs is caused by abnormal keratin produc- examination of the injured foot are necessary. Often, the injury tion. Treatment of this condition consists of debridement of the or insult is obvious such as a puncture wound with the foreign abnormal tissue and topical antibiotic therapy. A paste of body still in the foot. When the problem is not as obvious hoof metronidazole and oxytetracycline is very useful in the treatment testers can be useful to localize the affected area. It is very of this disease. While treating this condition, it is necessary to important for the veterinarian to obtain good quality radiographs keep the foot clean and dry. This can be accomplished with of the injured foot. If there is a foreign body in the foot, it is important to take radiographs to outline its location. However, White line disease is caused by keratinolytic bacteria if the foreign body could potentially cause more harm if left in and fungi found ubiquitous in the environment. The pathogenic place while trying to obtain radiographs; remove the object.
organisms digest the keritanized tissue between the stratum Other advanced imaging techniques such as MRI or CT may be medium and stratum internum of the hoof wall. This type of useful to localize the diseased area.
infection is usually associated with abnormalities or defects in Foot abscesses are a very common problem in the the hoof. Chronic laminitis, excessive hoof length, hoof cracks, equine patient and if not identified and treated properly may and poor quality horn are all conditions that predispose the develop into a more serious problem. The best approach to hoof horse to “White Line Disease.” This type of infection may go abscesses is to establish drainage, protect the sensitive area, and unnoticed until lameness is apparent and the problem is very provide a clean environment. Topical antiseptics such as iodine- severe. Chlorine dioxide is often used to treat this disease once based solutions are commonly used over the abscess site. If the abscess does not resolve easily and is draining excessively, addi- In conclusion, early identification and treatment are the tional measures should be taken. Your veterinarian should cul- keys to resolving hoof infections. It is important to remember ture the site and an antibiotic sensitivity test performed. The that the hoof like any other injured or infected area needs a draining tract should be thoroughly cleaned and radiographs clean dry environment to heal. This can be accomplished in taken. If the coffin bone is infected, it may be necessary to per- many ways such as a treatment plate shoe, foot cast, or a simple form surgery to remove the dead and infected tissue. Broad- foot bandage in some cases. We must also remember that stabi- spectrum systemic antibiotics should be initiated lization of the foot is necessary if the supporting structures of Quittor is the horseman’s term for an infected collateral the hoof have lost integrity. Finally, a regular trimming/ shoe- cartilage. This type of infection can occur due to an abscess, ing schedule of ~ 6 weeks will help maintain the integrity of the puncture wound, laceration, or even pressure necrosis from blunt hoof and help prevent unwanted infections.
force trauma. This condition presents as a draining tract fromthe coronary band or just above the coronary band. The treat-

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