Control of rabies in foxes: what are the appropriate measures?

Abstract

Until recent years, the depopulation of reservoir species was the only feasible measure to break the transmission chain of rabies in wildlife. In Europe at the beginning of this century, when applied with compulsory muzzling and restrictions on movement, dog depopulation was shown to be effective before any large scale vaccination of dogs. Some examples of the success of the application of depopulation measures on wild carnivores in the past are described. But in the case of enzootics of rabies in the fox, the control measures applied to fox populations sometimes decreased the prevalence or postponed the invasion of an area but did not free or protect an area permanently. Some examples taken from France illustrate the difficulties of drawing clear conclusions from the results of control measures. Conversely, the oral vaccination of foxes was demonstrably successful in preventing the spread of rabies. However, mathematical modelling, historical considerations and first observations in areas in which foxes have been vaccinated strongly suggest that the 'traditional' methods of controlling fox populations, at least by hunting, should not be restricted because they complement the effects of vaccination.