Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 13, 2000
Publication Date: N/A
Technical Abstract: Cryptosporidium parvum is one of the most common causes of diarrheal disease in calves. There are no vaccines or effective drug treatments available for this parasite. We previously demonstrated that oral dosing of mice with compounds that affect polyamine metabolism resulted in significant protection from infection. Therefore, we assessed the ability of these compounds to protect calves from C. parvum infection. Calves were dosed orally with either putrescine, SL11047 (a synthetic spermine analog) or agmatine (a key intermediate in C. parvum polyamine metabolism). The number and timing of doses was similar to those previously found to be effective in mice. Calves were infected with C. parvum at 4-7 days of age depending on the treatment regimen. Diarrhea and oocyst shedding was evaluated and compared with that seen in calves not receiving treatment. Putrescine and SL11047 were not effective in preventing infection and caused neural toxicity in calves receiving the highest doses. Agmatine was not toxic, but failed to prevent infection at doses 5 times higher than those effective in mice. These data indicate that the parameters required for effective chemoprophylaxis in an animal model of C. parvum infection may be different for the target species.