Prevalence of Agglutinating Antibodies to Neospora caninum in Raccoons, Procyon lotor

Neospora caninum is an apicomplexan parasite that causes neonatal neuromuscular disease in dogs and abortions in cattle. Dogs are the only proven definitive host. Little is known about the prevalence of antibodies to this parasite in wildlife. Sera from 99 raccoons (Procyon lotor) were examined for agglutinating antibodies to N. caninum using the modified agglutination test employing formalin-fixed tachyzoites as antigen. Raccoons originated in Florida (n = 24, collected in 1996), New Jersey (n = 25, collected in 1993), Pennsylvania (n = 25, collected in 1999), and Massachusetts (n = 25, collected in 1993 and 1994). Ten (10%) had antibodies to N. caninum; 9 had titers of 1:50, and 1 (1%) had a titer of 1:100. The present study indicates that raccoons have minimal exposure to N. caninum. The sera were also tested for agglutinating antibodies to Toxoplasma gondii and 46 (46%) were positive; 16 had titers of 1:50, 8 had titers of 1:100, and 22 had titers of ≥1:500.