The effect of dexamethasone on bovine coccidiosis.

When dexamethasone was administered intramuscularly to Hereford calves at the time of inoculation with Eimeria zurnii and E. bovis, there was no apparent effect on the resulting infection. Medication at the time of appearance of the clinical signs caused sufficient aggravation of the disease to result in the death of the animals. Administration of the drug after subsidence of the clinical signs did not cause a clinical relapse, but resulted in prolonged oocyst discharge in the feces. Treatment of uninoculated normal calves with dexamethasone caused a brief period of increased oocyst discharge without clinical signs.