Studies on laminitis in the horse II-pathogenesis

ABSTRACT

The microscopic evaluations in acute laminitis were classified into two main phases. Vascular phase The first changes were detected in the vasculature in the form of microthrombosis in the dermal capillaries, severe interstitial edema and hemorrhage in the primary dermal laminae during the first three days. These changes were manifested clinically by wariness of the hoof wall and coronary b and and bounding in digital pulsation. Epithelial phase The main epithelial changes were disconfiguration, epithelial cell hyperplasia, hyperkeratinization, necrosis of the laminae within 20 and 30 days. Clinically, there were marked rotation of the third phalanx, flattening of the sole, coronitis, appearance of laminitic rings and spesis of the foot. Progressive pathological changes leading to hoof wall deformity as a result of formation of intermediate degenerative layers separating the stratum lamellatum and third phalanx from the hoof wall, rotation, perforation of the solar aspect and sepsis and appearance of the air or gas in the laminar region of the hoof wall on lateral radiographic during chronic laminitis