Carbohydrate alimentary overload laminitis.
Authors: Pollitt, Visser
Journal: The Veterinary clinics of North America. Equine practice
Summary
# Editorial Summary: Carbohydrate Alimentary Overload Laminitis Pollitt and Visser's 2010 review examines the pathomechanics of carbohydrate-induced laminitis, a condition where excessive dietary fermentable carbohydrates precipitate structural failure at the lamellar dermal–epidermal junction—the critical load-bearing interface of the distal phalanx. The authors synthesise histopathological findings to establish a grading system that tracks sequential changes within secondary epidermal lamellae, basal cells, and the basement membrane as acute laminitis develops, providing a framework for understanding disease progression from subclinical to overt mechanical failure. Whilst the review clarifies the consistent microscopic pattern of lamellar pathology, it identifies a significant knowledge gap: the precise biochemical and inflammatory trigger mechanisms linking carbohydrate overload to lamellar cell death remain unidentified. For practitioners, this means recognising that dietary management—particularly strict limitation of nonstructural carbohydrates and rapid fermentable substrates—remains the most reliable preventative strategy despite incomplete understanding of underlying pathophysiology. Understanding both the structural consequences and the identified mechanistic gaps should prompt closer attention to forage quality, grazing management, and feed composition in laminitis-prone horses, whilst highlighting the need for continued research into causative triggers.
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Practical Takeaways
- •Understanding the lamellar failure site helps explain the biomechanics of laminitis but does not yet provide targets for preventing carbohydrate-induced cases
- •Histopathologic grading provides a standardized method to assess laminitis severity and progression, useful for research and prognostication
- •Until trigger factors are identified, dietary management remains the primary preventive strategy for carbohydrate-sensitive horses
Key Findings
- •In acute laminitis, failure occurs at the lamellar dermal/epidermal interface at the level of the suspensory apparatus of the distal phalanx
- •A grading system for laminitis histopathology is based on consistent patterns of changes to secondary epidermal lamellae, basal cells, and basement membrane
- •The specific trigger factors of carbohydrate-induced laminitis remain unidentified despite documented histopathologic patterns