High prevalence of Capillaria plica infections in red foxes (Vulpes vulpes) in Southern Germany

The nematode Capillaria plica is an ubiquitous parasite of the urinary tract of Canidae and Felidae. It causes a wide spectrum of clinical symptoms, ranging from asymptomatic infections to urinary bladder inflammation, pollacisuria, dysuria, and hematuria. Foxes serve as reservoir hosts and are considered to be a potential source of infection for companion and hunting dogs as well as domestic cats which acquire the infection by ingestion of earthworms which are the intermediate hosts. Despite its importance, epidemiological studies on this parasite are scarce and almost entirely lacking altogether for Central Europe. Therefore, we examined 116 red foxes (Vulpes vulpes) for the infection of C. plica by pathologic examination of the urinary bladders and microscopy of mucosal smears and urine sediments. The parasite was detected in 90 (78%; 95% CI, 68.9–84.8%) of the foxes, originating from all administrative districts of Bavaria (Southern Germany). Since Bavaria is characterized by a high number of forests and wildlife sanctuaries that provide ideal living conditions for foxes, the corresponding risk of infection of companion and hunting dogs by oral ingestion of earthworms as the intermediate hosts can likewise not be excluded. Because of the scarcity of reports on prevalences of C. plica worldwide, we also include a brief review of the available literature.