Bumped kinase inhibitor 1294 (BKI-1294) treatment every other day at 10 mg/kg produces a marginal clinical response in Cryptosporidium parvum–infected calves despite a significant reduction in parasite propagation. A, Daily clinical health scores were significantly better in treated calves on days 3, 4, and 6–9 after infection (asterisks), compared with values for control calves (P < .05). B, Daily fecal consistency scores were significantly better in treated calves on days 4 and 6–10 after infection (asterisks), compared with values for control calves (P < .05). C, Daily oocyst shedding was significantly reduced for all days after infection in treated calves as compared to control calves (P < .005). D, The total number of oocysts shed over the duration of the trial was significantly reduced in treated calves as compared to control calves (P < .05). Data are for 6 control calves and 6 BKI-1294–treated calves. Scores for clinical health, fecal consistency, and oocyst counts (daily and total) were examined for significant differences by the 1-tailed Student t test. Abbreviation: SD, standard deviation.