Occurrence of dioctophymosis in canines within a riparian zone of the Río de La Plata watercourse, in Ensenada, Buenos Aires Province, Argentina.

Dioctophymosis is a parasitic disease occasioned by the so-called "giant kidney worm", Dioctophyme renale, a nematode with an indirect life cycle. This parasite's definitive host is the mink, Mustela vison, though numerous wild and domestic mammals as well as man can serve as final hosts. The worms also can be in ectopic locations in the body. We surveyed 692 canines by ecography, urine sampling, surgery, necropsy, and clinical examination and diagnosed 244 cases of dioctophymosis (35.3%). Of the cases of dioctophymosis identified, 30.7% were obtained by ecography, 45.9% by urinalysis, and 17.6% by both those techniques -in addition to positive findings through surgery (2.5%), necropsy (2.5%), and the spontaneous elimination of the parasites (0.8%). Cases of dioctophymosis were observed in animals as young as 4months of age up to 15years. The frequency of D. renale diagnosis throughout the sampling period varied significantly. There was a statistically significant association between risk factors (swimming in the river, eating frogs, fish or eels, drinking ditch water) and the prevalence of infection. It was discussed the period missing after infection in canines.

Prevalence of a zoonotic parasite, dioctophyma renale (goeze, 1782), among male canines in a wild riverside area of la plata river, province of Buenos Aires, republic of Argentina

Dioctophymosis is an helminthiasis with an indirect life cycle caused by Dioctophyma renale. It mayaffect both humans and other mammals. The purpose of this study was to determine the prevalenceof the parasite in male canines of different ages, living in a wild riverside area of La Plata River with favourable characteristics for the development of eggs, intermediate or paratenic hosts and completionof the life cycle of D. renale. 171 animals were surveyed and samples were collected through urethral catheterization. The samples were processed by means of centrifugation at a relative centrifugal force of 700 g and microscopic observation of sediments. 42.1 percent of canines exhibitedpatent Dioctophymosis in their kidneys. Male canines between the ages of 2 and 5 showed the highest frequency of positive results. Several epidemiological risk factors are discussed that, whenassociated, might favour the high prevalence of this parasite in the area. The need for equipment for the indirect diagnosis of the disease in canines and other animals prone to infection is clearly demonstrated.

La Dioctofimosis es una helmintiasis de ciclo de vida indirecto causada por Dioctophyma renale. Puede afectar a los seres humanos y diferentes mamíferos. El propósito de este estudio fue determinar la prevalencia del parásito en caninos machos de diferentes edades, que viven en una zona rivereñaal Río de la Plata con características favorables para el desarrollo de los huevos, los huéspedes intermediarios o paraténicos y para el ciclo vida de D. renale. Fueron encuestados 171 animales, se recogieron muestras por medio de sondaje uretral. Las muestras se procesaron por centrifugación a una fuerza centrífuga relativa de 700 g y se observaron los sedimentos microscópicamente. El 42,1 por ciento de los caninos exhibió Dioctofimosis patente en sus riñones. Los caninos de sexo masculino con edades comprendidas entre 2 y 5 años presentaron la mayor frecuencia de resultados positivos. Se discuten varios factores de riesgo epidemiológico que asociados, podrían condicionar la elevada prevalencia de parasitosis en la zona. Se hace evidente la necesidad de equipos para el diagnósticoindirecto de la enfermedad en los caninos y otros animales propensos a infectarse.