Ultrasonographic Signs of Dioctophyma renale (GOEZE, 1972) in a Maned Wolf (Chrysocyon brachyurus)

Abstract

The ultrasonographic signs of dioctophimosis in a captive maned wolf (Chrysocyon brachyurus) at the Federal University of Mato Grosso (UFMT) Zoo are described in this study. On ultrasonographic examination, the right kidney exhibited marked alterations in size and architecture, with small hyperechoic ring-shaped structures of similar diameter in the transverse plane, immersed in anechoic fluid beneath a hyperechoic capsule. The animal underwent total right nephrectomy and the parasite (Dioctophyma renale) causing the disease was identified on macroscopic examination. This nematode is recognized as the largest parasitic roundworm in domestic carnivores, primarily affecting the kidneys of these animals. The maned wolf described in this report had no prior history of renal disease, and the routine examinations were part of the zoo’s preventive health program. The use of ultrasound images should be considered a screening test for lobos-guará, even asymptomatic ones, and may be useful for the identification, treatment and control of this parasitic disease, because the renal deterioration caused by D. renale may reduce the survival of lobos-guará in their natural habitat, leading to a decline in the population of these animals. The ultrasonographic appearance of the lesions was highly characteristic, facilitating the exclusion of other diseases and supporting the use of ultrasound for the diagnosis of dioctophymosis in this species.

Keywords: Dioctophimosis. Zoo. Wild Animals. Nematode. Renal Parasite.