Transmission of louping-ill virus in goat milk.

The course of louping-ill virus infection was examined in lactating goats. Seven goats were inoculated subcutaneously and titres of virus in blood and milk were monitored. All goats became viraemic with maximum titres of between 10(1.6) and 10(4.0) plaque forming units (pfu)/0.2 ml. Virus was also detected in the milk of all goats at maximum titres of between 10(0.6) and 10(5.7) pfu/0.2 ml. Only one of these goats exhibited clinical signs which were transient. In contrast, five of the 13 kids sucking these goats became infected and all showed marked clinical signs and one died and two were killed in extremis. It is considered that goats do not represent an efficient maintenance host for louping-ill virus but the excretion of virus in milk could represent a public health hazard.