Clinico-hematological, patho-anatomical and molecular based investigation of blackleg disease in Cholistani cattle

Clostridium chauvoei, causing myonecrosis in livestock animals, lives in the feces, surface water and soil. The blackleg due to C. chauvoei is very common in dairy animals. Still, no report is available about the pathophysiology of disease in Cholistani cattle kept under tropical and desert conditions of Cholistan, Pakistan. Therefore, in this study, we report for the first time the pathophysiology of a visceral form of blackleg infection in indigenous cholistani cattle breed reared in desert conditions of Cholistan. Clinically morbid animals exhibited different signs of infection including fever, crepitation sounds, gaseous swelling and edematous lesions. Blood was collected for hematological and serum biochemical investigation. Hematological examination indicated a significant increased erythrocyte sedimentation rate, lower red blood cells, hematocrit, and total white blood cell count. Results on serum biochemistry showed significantly (p<0.02) increased creatine kinase levels, creatinine, urea, alanine aminotransferase, aspartate aminotransferase, alkaline phosphates, creatinine phosphokinase and lactate dehydrogenase in infected cattle. At necropsy level, light pink color fluid under swelling areas of skin, gas bubbles, dark to black in color of affected muscles and crepitation sounds at palpation were observed. Necropsy showed marked myocarditis, petechial hemorrhages, consolidation and severe pulmonary edema. Spleen showed petechial hemorrhages and congestion. Histological analysis of muscular tissues indicated severe inflammatory reaction comprising of cellular infiltration, marked edema, necrosis and disruption of myofibrils. PCR confirmed the presence of C. chauvoei in muscles, heart and exudates of the lungs. This is the first report on molecular detection of Clostridium chauvoei from a visceral form of Blackleg disease in cholistani breed of cattle naturally infected in the Cholistan desert of Punjab, Pakistan.