Dioctofimose na região Sul do Rio Grande do Sul: ocorrência, diagnóstico e atividade ovicida de extratos vegetais de Solanum lycocarpum

Abstract

Dioctophyme renale is a nematode with worldwide distribution and zoonotic potential, capable of parasitizing the kidneys of domestic and wild mammals, especially dogs. Since dioctophymosis is treated by nephrectomy, the use of plant extracts with ovicidal potential, such as Solanum lycocarpum, may contribute to controlling the disease. Therefore, this study aimed to verify the cases of dioctophymosis in dogs and cats in the extreme south of Rio Grande do Sul (RS), the elimination of helminth eggs in the urine of parasitized dogs after nephrectomy, as well as the ovicidal activity and cytotoxicity of aqueous extracts of S. lycocarpum on D. renale eggs. Data from dogs and cats diagnosed with the disease in veterinary centers were analyzed, as well as urine samples one day before and 10 days after nephrectomy of 15 dogs with dioctophimosis using the centrifugal sedimentation technique. Furthermore, two aqueous extracts (EA1 and EA2) were tested in vitro on D. renale eggs (0.31 to 10 mg.mL-1), and cytotoxicity was assessed on bovine kidney cells (0.31 to 40 mg.mL-1). There were 240 cases of dioctophimosis in dogs and nine in cats, most of which were mixed breed, female, young adults and had signs of hematuria. Furthermore, ultrasound was the most commonly used diagnostic method, and the right kidney was the most affected organ. Most of the animals had a history of outdoor use and were from Pelotas, Capão do Leão and Morro Redondo. In urine analysis, 93.33% of dogs eliminated D. renale eggs after nephrectomy, three of them up to day 10. The aqueous extracts of S. lycocarpum inhibited the embryonation of D. renale eggs by more than 99% after treatment with 0.62 mg.mL-1 (EA1) and 1.25 mg.mL-1 (EA2). The aqueous extracts were not cytotoxic at concentrations of 0.31 to 10 mg.mL-1 in extract EA1 and at concentrations of 0.31 to 20 mg.mL-1 in extract EA2. Therefore, it is concluded that the southern region of RS has the largest case series of dioctophimosis in dogs and cats in the world, with the municipality of Pelotas standing out. Furthermore, dogs with dioctophimosis can eliminate helminth eggs in their urine for 10 days after removal of the parasites, and extracts of S. lycocarpum have ovicidal potential in D. renale eggs, being promising for environmental control of the helminth.