Causes of non-inflammatory laminitis

• A. Breakdown of collagen attachment, laxity of collagen attachment, epidermal growth
• B. Endotoxin
• C. Ruminal acidosis
• D. Relaxin

Answer: (A)

Non-inflammatory laminitis stems from weakening of the laminar attachments themselves, not from an inflammatory process. The hoof wall and the distal phalanx are held together by collagen-based attachments in the laminae; when these attachments break down, the connection weakens and laminar separation can occur under normal or excessive load. Laxity of the collagen attachments means they are easier to pull apart, increasing the risk of micro-separation, rotation, or sinking of the coffin bone. Epidermal growth reflects remodeling of the hoof tissue in response to this injury, which can contribute to structural changes in the hoof. Inflammatory triggers like endotoxin or ruminal acidosis drive immune and vascular responses that characterize inflammatory laminitis, not the non-inflammatory variety. Relaxin is not a relevant factor in this hoof pathology. So the combination of breakdown and laxity of collagen attachments with epidermal growth best explains non-inflammatory laminitis.