Prevalence of Cryptosporidium, Giardia and Eimeria infections in post-weaned and adult cattle on three Maryland farms

The prevalence of Cryptosporidium, Giardia and Eimeria, in healthy, asympto matic, post-weaned and mature cattle was investigated on three Maryland far ms. One farm, a dairy research facility, had 150 multiparous Holstein milki ng cows; 24 were examined and Cryptosporidium andersoni was detected in thr ee (12.5%) but neither Giardia nor Eimeria was detected. The second farm, a commercial dairy, had 57 multiparous Holstein milking cows and an equal nu mber of heifers. Of 19 cows examined, C. parvum, Giardia duodenalis, and Ei meria bovis and/or E. ellipsoidalis were detected in two (10.5%), two (10.5 %) and one (5.26%) cow, respectively. Of 23 heifers examined, C. parvum, Gi ardia, and E. bovis and E. ellipsoidalis, was detected in two (8.7%), four (17.4%), and five (21.7%), heifers, respectively. The third farm, a beef ca ttle breeding and genetics research facility, had 180 7- to 9-month old pur ebred black Angus. Of 118 examined for C. parvum and Giardia, 34 (28.8%) an d 44 (37.3%) were positive, respectively, of 97 examined for E. bovis and/o r E. ellipsoidalis 32 (33.0%) were positive. These findings, based on a met hod with a minimum detection level of 100 oocysts of C. parvum/g of feces, which underestimates the number of infected cattle, clearly demonstrate the presence of low level, asymptomatic infections in post-weaned and adult ca ttle in the United States and indicate the potential role of such cattle as reservoirs of infectious parasites. Published by Elsevier Science B.V.