Footrot in Cattle (Interdigital phlegmon, Foul in the foot)
Description Signs of foot rot include swelling of the coronary band with spreading of the toes and/or necrosis of tissue between the toes. This is a common cause of lameness in cattle. Caused by a combination of anaerobic bacteria. Untreated cases often develop secondary joint and tendon sheath infection.
Footrot is a subacute or acute necrotic infection originating from a lesion in the interdigital skin that leads to a cellulitis in the digital region. Pain, severe lameness, fever, anorexia, loss of condition, and reduced milk production are major signs of the disease. Footrot has a worldwide distribution and is usually sporadic but may be endemic in intensive beef or dairy cattle production units. The incidence varies according to weather, season of year, grazing periods, and housing system. On average, footrot accounts for ~15% of claw diseases.
The fore- or, more commonly, the hindlimbs can be affected, but more than one foot is rarely involved at the same time in mature cows. However, footrot can occasionally develop in several feet in calves. The first sign is swelling and erythema of the soft tissues of the interdigital space and the adjacent coronary band. The inflammation may extend to the pastern and fetlock. Typically, the claws are markedly separated, and the inflammatory edema is uniformly distributed between the 2 digits. The onset of the disease is rapid, and the extreme pain leads to increasing lameness. In severe cases, the animal is reluctant to bear weight on the affected foot. Fever and anorexia are seen. The skin of the interdigital space first appears discolored; later, it fragments with exudate production. As necrosis of the skin progresses, sloughing of tissue is likely to follow. A characteristic foul odor is produced.
Hematogenous infection of the tissues of the interdigital space may account for peracute cases of footrot, which are referred to as either “blind” or “super foul.” This form of footrot is characterized by the initial absence of a skin lesion, extreme pain, and the tendency to progress despite aggressive therapy.