What are carrier animals and what role do they play in outbreaks?
• The issue of carrier animals has been generally greatly over-exaggerated. Carrier animals are those individuals in which virus can be detected more than 28 days after infection. The virus has been recovered from the throat of Domestic sheep for up to nine months post infection and from Domestic cattle for 3 years. Numerous scientific experiments under biosecure conditions over the decades have failed to demonstrate transfer of virus from carrier livestock to susceptible animals. There is some epidemiological (field) evidence suggesting that carriers may be sources of infection for other livestock occasionally.
