State laminitis cannot occur in

• A. Vasoconstriction
• B. Vasodilation
• C. Calving
• D. Ruminal acidosis

Answer: (A)

Laminitis is driven by vascular and inflammatory events in the hoof, where increased blood flow and leakage (vasodilation) in the hoof capillaries contribute to edema and damage to the laminae. Conditions like ruminal acidosis and the associated endotoxemia promote this inflammatory, vasodilatory state, and the stress of calving can also predispose to these systemic changes. Vasoconstriction, on the other hand, reduces perfusion to the laminae and dampens the inflammatory cascade, making the development of laminitis unlikely. So the state that laminitis cannot occur in is vasoconstriction.