Laminitis is more common and more important than it is usually given credit for. There is some (probably unnecessary) disagreement over the naming of this condition, since there are no laminae on the sole in cattle, meaning a more accurate name would be 'coriitis'. Inflammation of the sensitive corium causes pressure pain and loss of cohesion between the horn and the underlying structures of the foot. The inflammation can also compromise the blood supply to the horn-producing papillae at the coronary band and across the sole. This leads to the production of poor quality horn, which explains why laminitis predisposes cattle to sole ulceration and white line disease. A transient period of laminitis can cause the production of a double sole.
Acute laminitis is the most problematic. The animal will be reluctant to stand or walk, preferring to remain recumbent. The feet will have increased blood flow and hence a raised temperature compared to normal, and strong digital pulses. It is associated with acute ruminal acidosis (eg by carbohydrate overload) or acute endotoxaemia (eg toxic mastitis, toxic metritis). Non-steroidal anti-inflammatory therapy should be given.
Chronic laminitis is characterised by changes in claw shape as a result of the long term aetiology. The claws become flat and square and often have horizontal ridges. It is associated with continuous high energy feeding, which should be addressed to treat the condition. There is a proven hereditary predisposition in Jerseys.