CC: Equine laminitis: A revised pathophysiology

Vasodilation precedes the development of carbohydrate overload laminitis. Circulating laminitis trigger factors activate lamellar enzymes, which lyse the attachments between the distal phalanx and the inner hoof wall. The clinical signs of laminitis occur when the lamellar architecture disintegrates. The amount of pain correlates with the extent of lamellar pathology. A substance produced by Streptococcus bovis from the equine hindgut activates lamellar enzymes and causes in vitro laminitis. The S. bovis laminitis trigger factor may be the ‘‘missing link’ ’ connecting events in the hindgut with the development of laminitis in the foot. Author’s address: Australian Equin