Prothrombotic changes occurring in the prodromal stages of carbohydrate-induced laminitis were investigated. Hemostatic alterations were evaluated by determining platelet counts, platelet survival, activated partial thromboplastin time, one-stage prothrombin time, and monocyte procoagulant activity. Thrombosis of vessels in the hoof wall was evaluated by contrast arteriography and histologic examination. Of 5 horses, 4 became lame between 28 and 52 hours after carbohydrate administration. Mean platelet count in laminitis-affected horses was lower throughout the prodromal stages of laminitis, compared with that in control horses, but differences were not statistically significant. However, survival of indium-111-labeled platelets was less than the value in control horses by 6 hours after carbohydrate administration. Arteriography of disarticulated feet revealed marked reduction in blood supply to hooves in laminitis-affected horses. Histologic examination of the laminar dermis disclosed microthrombi in venules of the laminar dermis in 2 of 4 affected horses. Statistically significant changes in prothrombin time were not observed, and changes in activated partial thromboplastin time were slight and occurred only at the onset of lameness. Statistically significant changes in monocyte procoagulant activity were not observed. Plasma endotoxin-like activity was not detected in laminitis-affected horses. These data indicate that platelet survival was decreased within the first 6 hours after induction of carbohydrate-induced laminitis, but systemic activation of the coagulation system was not detected.

Forty-five claw lamed cows with pododermatitis circumscripta, hyperplasia interdigitalis, and dermatitis verrucosa were treated surgically through resection of necrotic tissues, currettage, antibiotics application, and compressive bandage, under retrograde intravenous regional anesthesia of claw. At 7 days postoperation were showed lameness score 0, absense of swelling of extremitis, without fistulation and purulent exudate in wound. Mean duration time of action of local anesthetic drug was 75 minutes and mean operation time for treatment of pododermatitis circumscripta, hyperplasia interdigitalis, and dermatitis verrucosa was 35 minutes, 20 minutes, and 21 minutes, respectively.