Acute Babesia bovis infections: renal involvement in the hypotensive syndrome

Splenectomised calves in metabolism cages were infected with Babesia bovis. During the infection, urine samples were collected and analysed for electrolytes, proteins, kinin, and urinary kallikrein. During the later stages of the infection there were significant reductions in urinary volume, water intake, urinary kinin, kallikrein, and electrolytes. Proteinuria was detected from 3--8 days postinfection of which 15--20% was haemoglobin and most of the remainder was albumin (70--75%). Fibrin degradation products, fibrinogen-like products, and haptoglobin were not detected. Degeneration of cortical tubules was detected by histological studies. As these tubules produce urinary kallikrein it seems probable that diminished glomerular blood flow and hence glomerular filtration rate are due to decreased production of this enzyme.