A total of 125 horses, 4-12 years old from both sexes were used in this study, among these, 100 animals were clinically suffering from acute and chronic laminitis and 25 clinically normal horses served as controls. Results indicated to the presence of different etiological factors exhibited laminitis in horses, such as dietetic causes concerned with consumption of large quantities of carbohydrates and lush green food ,post parturient metritis, repeated and Iatrogenic use of corticosteroids, bad shoeing, lameness due to defective legs, enteritis of different causes, pneumonia, pleurisy and babesiosis. Diseased horses exhibited different clinical sings according to the severity of the disease, forward the forelimbs or downward the hind limbs under belly with uncomforted standing, pain and increased hoof temperature, palmer (digital) pulsation, severe sweating, lameness with uncontrolled movement and recumbency, moreover, because of chronic affection, deformities and fissures have been encountered on hoof wall. Statistically significant increase in body temperature, respiratory and heart rate were encountered in horses suffered from acute type of laminitis. Evaluation of lameness according to Obel grad were also encountered in this study and results show, (12%) of affected horses classified as grad (1), (61%) were classified as grad (2), (21%) were classified as grad (3) and (6%) were classified as grad (4). Results were also showed significant increased in PCV and TLC in horses affected with acute type of laminitis. Neutrophilia and lymphopenia were detected in horses show acute laminitis. Laminitis have substantial effect on clotting factor indices and the results indicated significant decrease in total platelets count with significant increase in their size and distribution rate, moreover, significant increase have been also recorded in clotting time, prothrombin time and activated partial thromboplastine time, in animals affected with acute laminitis. Results of biochemical tests revealed significant increase in Matrixmetalloproteinaes-2, hapotoglobin in horses affected with acute type of laminitis, however fibrinogen values were increased significantly in horses affected with acute and chronic laminitis.