Methods of Control and Prevention

Since caseous lymphadenitis is effectively untreatable with antibiotics, prevention and control of the disease relies on the application of strict management and hygiene practices. The pus in the abscesses contains huge numbers of active and infectious bacteria and any sheep with lesions has the potential to contaminate the environment.

Future efforts to eradicate the disease may focus on the development of vaccination programmes (Hodgson et al., 1994) and testing programmes to identify carriers (Laak and Schreuder, 1991; Schreuder et al., 1994).

If the disease is confirmed in the flock, infected sheep should be isolated and removed from the flock for slaughter. When sheep are being sheared the clipper blades should be dipped in strong disinfectant between animals. Any cuts on sheared sheep should be treated with antiseptic (Paton et al., 1988; Paton et al., 1996; Serikawa et al., 1994). Iodine may be used for this purpose under organic management. Any pus discharged onto floors or bedding should be cleaned up and the area disinfected. Dipping should be carried out no sooner than 2 weeks after shearing (Nairn and Robertson, 1974). Farmers should maintain good hygiene during lambing, docking and castration.

It is advised that all new arrivals should be quarantined and examined prior to mixing with existing stock and if any animals are showing swelling or discharging abscesses they should be isolated and checked out (Scott et al., 1997). A closed flock policy, such as many organic farmers apply, will reduce the risk of introducing the disease.

Since the disease has been known on rare occasions to transfer to humans, it is wise to pay extra attention to personal hygiene when handling affected animals.