Dioctophyma renale in 28 dogs: clinicpathological and ultrasonographic findings

Dioctophyma renale infection in dogs is being considered uncommon for most parts of the world. However, some regions show an increase of this infection; but many data of the epidemiology and the biological cycle of the parasite are still unclear. The present study describes the epidemiological, clinicpathological and ultrasonographic aspects of 28 cases of infection by Dioctophyma renale in dogs in the West Frontier region of Rio Grande do Sul, Brazil. Street dogs were the most affected and all of them had access to the banks of the Uruguay River. The renal and extra-renal lesions were predominantly characterized by atrophy of the renal parenchyma, sclerotic glomerulonephritis and granulomatous peritonitis, associated with free adult parasites and eggs in the abdominal cavity and erratic migration into the subcutaneous tissue. The ultrasound findings corresponded especially to the circular cross-sectional images with 0.6cm in diameter at most, with hyperechoic margin and hypoechoic center too. These findings were pathognomonic for Dioctophyma renale infection and this examination was essential for the definitive diagnosis by clinical evaluation. The results of the study demonstrate the importance of this parasitism in the region, alert that the diagnosis has being underestimated, and point out the need to clarify its epidemiology in order to reach effective control measures.