Pathomorphological changes of the hepatorenal system in dogs with babesiosis

Abstract

Canine babesiosis is a highly relevant parasitic disease characterized by systemic involvement of the organism and the development of severe complications associated with massive intravascular hemolysis. The aim of this study was to determine the morphological features of liver and kidney alterations in dogs affected by babesiosis and to analyze the underlying pathogenetic mechanisms of these changes. A comprehensive approach was applied, including necropsy examination, macroscopic assessment, and histological analysis of liver and kidney samples obtained from infected animals, followed by microscopic evaluation of structural alterations. The study demonstrated that hepatic lesions develop as a consequence of intravascular hemolysis, which triggers a cascade of toxic–hypoxic disturbances accompanied by endogenous intoxication, endothelial injury, and microcirculatory disorders manifested as stasis and sludge phenomena. Progressive hepatocellular hypoxia leads to granular and vacuolar degeneration, followed by necrobiotic and necrotic changes with disruption of hepatic trabecular architecture. In addition, sinusoidal congestion, cholestasis, and hemosiderin accumulation were observed, reflecting the intensity of hemolytic processes. Renal lesions were characterized by organ enlargement, venous congestion, and interstitial edema. Histologically, pronounced microcirculatory disturbances were observed, including capillary hyperemia, stasis, partial glomerular collapse, and dilation of Bowman’s space. The most severe alterations were detected in the tubular epithelium, where granular and vacuolar degeneration, epithelial desquamation, karyorrhexis, and karyolysis were present, along with the formation of hemoglobin pigment casts within tubular lumina. These changes corresponded to acute tubular necrosis and hemoglobinuric nephrosis, leading to the development of acute renal failure. The obtained results indicate that morphological alterations in the liver and kidneys in babesiosis are systemic in nature and result from the combined effects of hemolytic intoxication, hypoxia, and microcirculatory disorders. These mechanisms form the basis of hepatorenal syndrome and largely determine disease severity and high mortality in affected dogs. The findings contribute to a deeper understanding of babesiosis pathogenesis and may be useful for improving diagnostic approaches and prognostic assessment in veterinary practice.