Capillaria plica in Red Foxes (Vulpes vulpes) from Serbia: Epidemiology and Diagnostic Approaches to Urinary Capillariosis in Domestic Carnivores

Purpose: This study aimed to determine the presence of C. plica in red foxes and to point out the possibilities of different diagnostic methods, that could be used for diagnosis of urinary capillariosis in domestic carnivores. Methods: Seventeen red foxes from hunting grounds in the Kolubara District, Republic of Serbia, were examined in February 2019. Animals to be shot were selected based on the criteria of gamekeepers and the permission of the competent Ministry. After hunting, the foxes were examined by ultrasound and autopsied. After the necropsy, biochemical and sediment analysis of urine morphological identification of isolated adult parasites, and macroscopic/microscopic examination of the urinary bladder and kidney tissue were performed. Results: Adults of C. plica were detected in 3/17 foxes (17.6%) by ultrasound imaging and in 6/17 foxes (35.3%) by necropsy examination. Parasite eggs were found in the urinary sediment of 9/17 foxes (52.9%). The predominant histopathologic changes were amyloid degeneration of the renal glomeruli and proximal tubules (8/17 foxes-47%) as well as acute cystitis (7/17 foxes-41.2%). The occurrence of C. plica was determined in 12/17 (70.6%) of the examined foxes. Discussion: This study is the first record of the C. plica in red foxes in the Republic of Serbia. Diagnostic methods used in this study could make possible the early revealing of capillariosis in domestic carnivores and could provide reliable clinical and parasitological screening of suspect animals. Conclusion: The study presents the first report of urinary capillariosis in a fox population in Serbia. The established high prevalence of C. plica in foxes could presume its higher prevalence in domestic and wild carnivores in the future.