R. Niskanen et al., Lack of virus transmission from bovine viral diarrhoea virus infected calves to susceptible peers, ACT VET SC, 41(1), 2000, pp. 93-99
None of 14 calves not previously exposed to BVDV became infected after bein
g forced to have nose-to-nose contact with a group of 5 calves primarily in
fected with BVDV. These were 5 male calves primarily infected with a type I
BVDV strain, after nose-to-nose contact with a persistently viraemic calf.
All 5 became infected and were clinically affected. They were slightly dep
ressed and pyretic at 8-9 days post-infection, with a body temperature of u
p to 41.6 degrees C, but no medical treatment was required. Seroconversions
to BVDV were detected in these calves at 14 to 21 days post-infection. The
14 healthy calves, proved to be free from BVD virus - as well as antibodie
s, were introduced 2 by 2 into the group of 5 primarily infected calves on
days 4, 7, 14, 21, 28, 35 and 42 after the 5 calves had been in contact wit
h the persistently BVDV-infected calf. Each pair of calves stayed within th
e primarily infected group for 2 days. None of these 14 calves seroconverte
d to BVDV.