The effect of respiratory diseases of serum lactate dehydrogenase and its isoenzyme patterns in calves

In this study we examined the serum activity of lactate dehydrogenase (LDH) and its isoenzyme patterns in 28 calves of a lowland black spotted breed and its crossbreeds at the age of 2-6 months suffering from clinically noticeable manifested respiratory diseases – bronchopneumonia (BRD Group). As a control group we used 35 clinically healthy calves of the same age, breed and nutrition (Healthy Group). The sick calves did not show clinical signs or pathological lesions on other organ systems. The results found in sick calves showed a significantly higher total activity of LDH than in clinically healthy animals (P<0.01). The mean activity of LDH was 2012 U/l in healthy calves and in calves with respiratory diseases 2529 U/l. The differences in all LDH isoenzyme patterns between both groups of animals were significant (P