The morphometric characteristics of internal organs, the morphological composition of blood, and indicators of metabolic processes in the blood plasma and hepatopancreas of the two-year-old carp (<i>Cyprinus carpio</i> L.) from the conditionally clean pond and contaminated with sewage from a livestock enterprise pond were examined. It was established that the considered contamination caused increase of the spleen mass and its index respectively 1.63 and 1.65 times, but did not affect live weight, body length and height, body structure index, hepatopancreas mass and its index.
The hemoglobin concentration, number of erythrocytes, thrombocytes and monocytes in blood of carps from the contaminated pond was lower than in control, whereas number of the segmented neutrophils and ESR were higher, and the number of leukocytes, eosinophils, lymphocytes and rod-nucleated neutrophils did not differ.
Wastewater from the livestock enterprise affected metabolic processes in carp, particularly caused increase of the glucose and total protein concentration, the lactate dehydrogenase, aspartate aminotransferase and creatine kinase activity in blood plasma and hepatopancreas. At the same time, there were no differences between specimens from the conditionally clean and contaminated pond in terms of content of triglycerols, cholesterol, urea, creatinine, calcium, inorganic phosphorus, AlAT and AsAt activity in blood plasma and hepatopancreas and total protein content and LHD activity in hepatopancreas, content of total protein, glucose, creatinine, urea, the glucose content in hepatopancreas.
The established changes in internal organs, morphological composition of blood and metabolic parameters, particularly concentration of hemoglobin and the erythrocytes number in blood, glucose and total protein content, and activity of lactate dehydrogenase and creatine kinase in carp enabled to propose to use these parameters as supplementary over assessment of the ecotoxicological state of ponds contaminated by wastewater from livestock enterprises.