Equine disease of the upper respiratory tract is one of the more common medical conditions faced by horses. Therefore, this study aimed to conduct a survey on the most common cause of upper respiratory disease of horses in relation to clinical, haematological and biochemical changes. Special attention was given to the effect of inflammatory respiratory disease on cardiac function and muscle enzyme activity and their relations with trace element status. The study was applied to a total number of 120 horses (10 control and 110 diseased showed upper respiratory disease signs). Blood samples obtained from control and affected animals. Swabs from abscessed L. ns were collected from diseased animals.  The most prevalent clinical findings that appeared on horses with upper respiratory tract affections in this study were inappetance, fever, pharyngitis, cough, dyspnea, dysphagia, serous, purulent and mucopurulent nasal discharge, painful swelling and abscesses in submandibular, parotid and retropharyngeal lymph nodes that occurred as complications of the disease in addition to guttural pouch empyema. Bacteriological results revealed isolation of Streptococcus. equi as a major causative agent confirmed by PCR and there were significant increases in white blood cells, neutrophils, platelets count, cardiac troponin I, creatine kinase-myocardial band, procalcitonin, tumor necrosis factor alpha, interleukein-6, total CK, aspartate aminotransferase, fibrinogen and ceruloplasmin. While significant decrease in red blood cells, hemoglobin, hematocrit, lymphocytes, eosinophils, monocytes, iron, zinc and selenium were recorded. In conclusion, these findings highlight the need of early detection and targeted treatment options for management of upper respiratory disease in horses.