engleski

MORPHOLOGY OF ORGAN DYSFUNCTION IN DOGS WITH LETHAL BABESIA CANIS INFECTION

Babesiosis, caused by tick-transmitted, hemoprotozoan parasite Babesia canis, is a hemolytic disease which significantly affects Croatian dogs. Organ dysfunction in this systemic infection was so far accurately described through hematological and plasma proteins deviations. Pathological survey on dogs that died due to B. canis infection has never been systematically conducted. To describe morphology of organ dysfunction, 17 dogs found with jaundice, anemia, hepatosplenomegaly, pigmenturia, parenchymal and serosal petechiation were dissected during a two-year period. Genotyping from affected organs confirmed B. canis, as a cause of infection in all dogs. Lungs, heart, liver, spleen and kidney were selected for histology. In all cases, minimally three organs were morphologically changed. In the lungs of 16 dogs, capillary dilation and multifocal necrosis of alveolar septa followed with leakage of protein-rich fluid and erythrocytes caused hemorrhagic edema. Liver damage was evident in all dogs in form of centrolobular necroses, compressive atrophy, degeneration and dissociation of hepatocytes, mostly caused by hypoxia or severe diffuse dilation of sinusoids and spaces of Disse due to accumulation of protein-rich fluid. Massive red pulp histiocytosis with marked extravascular hemolysis was a constant finding in spleen samples, while segmental infarctions and hemorrhages were found in five dogs only. In 10 of 17 dogs, renal lesions differed from mild tubular epithelial degeneration, pigmenturia with pigment and protein tubular cast formations up to necrosis of tubular epithelial cells. Myocardial lesions were recorded in six dogs ; it consisted of endomisial edema, focal necroses and hemorrhages. Presence of microthrombi within capillaries indicating disseminated intravascular coagulation were present in the liver of three dogs and in the lungs of five dogs. B. canis causes vital organ damage by hypoxia due to hemolysis and massive capillary network dilation accompanied by increased vascular permeability. Cellular atrophy, and degeneration as well as single cell necrosis are consequence of aforementioned pathogenesis. Focal or disseminated segmental necroses and hemorrhages are direct outcome of capillary and/or venous and arterial thrombosis.

morphology ; organ dysfunction ; Babesia canis ; pathology ; histology ; genotyping

nije evidentirano