Culling and disposal

Inspecting animals and setting up checkpoints are important parts of the process of implementing movement controls; however, sometimes it is not possible to contain all animals and animal products. Checkpoints on major roads may cause unacceptable disruption, be too expensive to maintain or simply lead to people redirecting their animals onto minor roads where control points are known not to be present. Small livestock and poultry are readily concealed in vehicles and can be smuggled outside restricted areas.

Movement restrictions will be most effective when they have minimal impact on the animal owners. Restrictions that are considered to be temporary or of short duration are likely to receive more popular support. Perhaps an assessment of the relative risks will suggest that some animal products could be allowed to move with little risk of disease dispersal (e.g. those that are routinely treated so that they would be made safe or extremely unlikely to contaminate animals given their destination). Allowing a low level of risk, such as the movement of pasteurized egg products, might encourage compliance with some other measures that would have much greater useful impact.

Fear of losing their animals is an incentive for owners to move them away from an outbreak. This can be reduced if culling strategies are only applied to the extent necessary and where compensation is adequate and rapidly delivered. Further, effort must be taken to reassure owners that their animals will only be culled when it is really necessary and that they will be compensated.

When applying movement restrictions, good communication is essential and it goes hand in hand with disease control.

cullIng and dIsPosal

For most animal disease emergencies, some degree of culling is likely to be necessary. The greatest source of the infectious agent is actively infected and excreting animals. These animals are the most dangerous direct source of infection, but they may also lead to indirect infection through the movement of the infectious agent on inanimate objects (i.e. fomites), including vehicles, clothing and particularly people’s footwear. Production of the infectious agent effectively ceases when the animal is killed, although the carcasses may remain contaminated for a period after death.

Disposal of the dead animals is not an essential element of disease control, but it is important. Communities will usually object to dead animals being left lying exposed for more than a couple of days and the environmental impact of this is also great. There is a risk of disease being spread from these carcasses by scavengers, but most organisms of concern are relatively sensitive to the changing conditions in a carcass. For instance, FMD virus is destroyed quickly at a pH below 6 and most of a dead carcass achieves this quite quickly in most tissues. So the ability to dispose of culled animals must be taken into account as well as the ability to kill them.

Culling4 must be carried out in a humane manner. The actual method used varies from situation to situation. Where killing by free bullets is to be used, a careful assessment must be carried out to ensure that the firing lines are clear of people who could be accidentally injured. Those shooting the animals must be trained marksmen with experience in shooting

4 Culling methods vary and further advice may be obtained from the Terrestrial Animal Health Code and other

GEMP materials.