The present study was planned to demonstrate the clinical findings, post mortem lesions of BEF and to study the
effect of the disease on blood picture including red blood cells, hemoglobin concentrations, total and differential
leucocyte counts as well as total serum protein, serum albumin, glucose, alkaline phosphatase in addition to Kidney
function tests as creatinine and urea and finally biochemical parameters which include the estimation of serum
inorganic phosphorus, calcium and magnesium. The study was conducted on 30 Friesian dairy cows from private
farm at El-dalangat, Behera Governorate. 10 cows were clinically healthy and kept as control while 20 cows were
diagnosed clinically and confirmed by immunofluorescent (IF) test as bovine ephemeral fever. The results showed
clinical signs in the form of fever 40-41.5° C with waves of muscle shivering, fall in milk production and
accelerated heart and respiratory rates, depression, anorexia, ruminal atony, salivation, a generalized stiffness or a
shifting lameness of diseased cows, recumbency occurring in Many animals for 12-24 hours with sever tympany
but are able to rise if sufficiently stimulated. Recovery begins after sever clinical signs disappear and early
improvement that fever disappears in most cattle. A range of complications occurred in five cases. Death occur
suddenly in one case during febrile phase. Recumbency persist for three weeks in (2) cases and recovery from the
longer-term recumbence complete after three weeks and abortion occur in (2) cases in a late stage of pregnancy
(eighth month of pregnancy). The observed post mortum lesions were pulmonary emphysema, alveolar collapse,
exudate found in bronchioles and bronchioles became completely occluded by exudate, fibrin-rich exudate in
pleura, pericardial and in the joint capsules and Lymphadenitis. A significant decrease (p<0.01) in RBCs count and
hemoglobin concentration in cows suffering from bovine ephemeral fever. Also, there were marked leukocytosis,
neutrophilia and lymphopenia, but Monocytes, eosinophils and basophil percentage did not seem to be influenced,
In addition, total proteins, albumin, globulin, glucose, Inorganic phosphorus, calcium and magnesium showed
significant decrease (p<0.05), while alkaline phosphatase activity, urea and creatinine increased significantly
(p<0.01) in these diseased cows. It can be concluded that ephemeral fever in cattle has a range of hematological
and biochemical changes in blood which are characteristic of an inflammatory response, These information will
help to plane a strategy to decrease losses of the disease through effective treatment specially hypocalcaemia.