Detection and quantification of Dioctophyme renale eggs in dog urine after nephrectomy

Dioctophyme renale is a zoonotic nematode that parasitizes mainly right kidney of domestic and wild canines, and can affect humans, and its eggs are eliminated in urine. The duration of egg dissemination after surgical treatment is unknown. Therefore, the objective of this study was to identify, quantify, and verify the duration of the elimination of D. renale eggs in dog urine after the surgical removal of nematodes. The study involved 15 dogs in which female specimens of D. renale were detected in kidneys. Urine samples, preferably first-morning urine samples, were collected before and for the first ten days after nephrectomy. For egg quantification, 40 µL samples of urinary sediment were analyzed in triplicate. In laboratory analyses, between 900 and > 6,000 eggs/urine sample were detected in 86.7% of the dogs prior to surgery, and in 40% of the dogs on postoperative day 1. Of the 15 dogs evaluated, 14 (93.3%) eliminated D. renale eggs on each of the first ten postoperative days. Egg elimination peaked on postoperative day 1. Our results indicate that dogs can continue to be sources of D. renale infection even after the helminths have been removed from a parasitized kidney, underscoring the novelty of these findings and their importance for the One Health approach.