Fc. Rulofson et al., Fecal shedding of Giardia duodenalis, Cryptosporidium parvum, Salmonella organisms, and Escherichia coli O157 : H7 from llamas in California, AM J VET RE, 62(4), 2001, pp. 637-642
Objective-To evaluate fecal shedding of Giardia duodenalis, Cryptosporidium
parvum, Salmonella organisms, and Escherichia coli O157:H7 from ilamas in
California with respect to host factors and management practices.
Animals-354 Ilamas from 33 facilities.
Procedure-Fecal specimens were collected and examined for G duodenalis and
C parvum by means of immunofluorescent microscopy. Salmonella organisms wer
e cultured by placing feces into selenite enrichment broth followed by sele
ctive media. Escherichia coli O157:H7 was cultured by use of modified trypt
ocase soy broth followed by sorbitol MacConkey agar, with suspect colonies
confirmed by means of immunofluorescent microscopy.
Results-12 of 354 fecal specimens (3.4%) had G duodenalis cysts. Younger Il
amas (crias) were more likely to be shedding cysts, compared with older Ila
mas. Farm-level factors that increased the risk of shedding were large numb
ers of yearlings on the property (> 10), smaller pen sizes, large numbers o
f crias born during the previous year (> 10), and large pen or pasture popu
lations (> 20). None of the 354 fecal specimens had C parvum oocysts. Seven
ty-six (from 7 facilities) and 192 (from 22 facilities) Ilamas were tested
for Salmonella organisms and E coli O157:H7, respectively. All fecal specim
ens had negative results for these bacteria.
Conclusions and Clinical Relevance-Shedding of G duodenalis was primarily l
imited to crias 1 to 4 months old. Llamas from properties with large number
s of crias born in the previous year, resulting in large numbers of yearlin
gs in the current year, were at greater risk of infection. In addition, hou
sing Ilamas in smaller pens or pastures and managing Ilamas and crias in la
rge groups also increased the risk of G duodenalis shedding.