Infectious diarrhoea of neonatal calves is common worldwide. Several pathogens,
e.g. rotavirus and coronavirus, enterotoxigenic Eschericia coli bacteria and the
protozoan parasite Cryptosporidium parvum have the potential to cause diarrhoea
in calves. In this study, which was part of a larger project on calf diarrhoea in
South Vietnam, the occurrence of C. parvum in dairy calves was investigated.
One hundred and twenty faecal samples were collected from dairy calves in 4
state farms, each housing several hundred cows, and 35 household farms with 1-
100 cows in 6 districts between September and November 2006. Both diarrhoeic
and non-diarrhoeic calves, aged 1-60 days, were sampled. Fifty seven samples
were collected from state farms and 63 samples were collected from household
farms. Analyses were conducted by C. parvum antigen ELISA. The samples were
also used in a cooperating study to estimate the prevalence of rotavirus.
In total, 10 samples (8%) were positive for C. parvum, 3 of these were co-infected
with rotavirus. Forty five samples were from calves with diarrhoea. Four of them
were infected by C. parvum, and another 2 were co-infected with C. parvum and
rotavirus. Of the 75 samples collected from clinically healthy calves, 3 had C.
parvum only and 1 was co-infected with C. parvum and rotavirus.
Eight (80%) of the C. parvum positive samples were collected in state farms and
the remaining two were from household farms with 5-20 cows. The 3 samples that
were coinfected with C. parvum and rotavirus were from state farm calves. The
average occurrence of diarrhoea among the calves sampled in state farms was
54%, whereas 25% of calves sampled in household farms were diarrhoeic.
The results show that C. parvum and rotavirus are present among calves in South
Vietnam and might have clinical sig...
