Specimens should be collected from sacrificed animals or as soon after death as possible.
Viruses start losing viability when the animal dies.
Collect appropriate specimens aseptically with the same care as for bacteriologic specimens. It is most important that specimens for virologic studies be kept cold after collection and during shipment. Freezing is not necessary unless there will be a long delay before reaching the laboratory and it may interfere with some of the tests. If this is impractical, remove the head at the atlantol-occipital joint. The cerebrospinal fluid and cord may be infectious.