Epizootiology of canine distemper in New Jersey raccoons

Seventeen epizootics of canine distemper (CD) involving at least 615 raccoons (Procyon lotor) were identified between 1 September 1977 and 25 March 1991 in New Jersey (USA). Epizootics occurred three times at four year intervals in three areas. Based on this cycling, the wide distribution of CD cases, and their occurrence between epizootics, I propose an enzootic status for CD in New Jersey raccoons. The peak period prevalence of raccoon canine distemper cases occurred at the end of the mating season in March. Another period of CD activity began with increased movements of the young in September. Epizootics were associated with river drainages and other wetlands. Age and sex distribution of raccoons with CD was not significantly different (P > 0.05) from that of an asymptomatic composite sample of four northern New Jersey raccoon populations. Lethargy was the most commonly reported clinical sign in raccoons with alert or aggressive behavior rarely observed.