Urinary Tract Parasites

Capillaria plica is a helminth parasite of the canine urinary bladder. C. felis-cati is the feline counterpart. The ova are similar to those of Trichuris spp. in that they are oval in shape and have bipolar plugs (see picture). Since fecal contamination of the urine could result in the presence of whipworm eggs, the two must be differentiated. If the ova were seen in a well- handled urine collected by cystocentesis, fecal contamination could be ruled out. Additionally, the ova of C. plica are colorless and rougher in texture compared to the smooth, yellowish eggs of T. vulpis. Dioctophyma renale, the giant kidney worm, has large, yellow-brown, thick-walled ova with a characteristic wavy surface (not pictured). Eggs may be seen in urine if a gravid female worm is present. Though endemic in areas of Canada, the infection is very rare in the United States.

Last Updated: January 16, 1996