Some pathophysiological changes associated with infection of Eimeria zuernii in calves.

Twelve Holstein-Friesian calves were divided into two groups, one of which was infected with Eimeria zuernii. Fecal oocyst output, weight changes and various blood, cellular, protein and biochemical constituents were examined for both groups. Maximal fecal oocyst output occurred 21 days after infection. Both groups of calves gained weight in a linear fashion until day 21 postinfection when the infected group lost weight rapidly. The packed cell volume of the infected calves appeared markedly reduced. Although there was a reduction in plasma proteins it did not appear significant. There was a significant reduction in plasma Na+ and Cl- ions of the infected calves. There were no significant changes in the other blood constituents examined.