Javier Aníbal Origlia¹ | Marcos Javier Butti² | María Manuela López³ | Nelly Grisell Martínez³ | Luis Fazzio⁴ | María Inés Gamboa² | Nilda Radman²

1. Cátedra de Patología de Aves y Pilíferos, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina y Estación de Cría de Animales Silvestres (ECAS), Dirección de Flora y Fauna, Ministerio de Desarrollo Agrario, Buenos Aires, Argentina; Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias, Cátedra de Parasitología Comparada, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina; 2. Laboratorio de Parasitosis Humanas y Zoonosis Parasitarias, Cátedra de Parasitología Comparada, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina; 3. Estación de Cría de Animales Silvestres (ECAS), Dirección de Flora y Fauna, Ministerio de Desarrollo Agrario, Buenos Aires, Argentina; 4. Laboratorio de Patología Especial Veterinaria (LAPEVET) Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina.

Ponente: Javier Aníbal Origlia, javieroriglia@yahoo.com

Dioctophimosis is a helminthiasis caused by Dioctophyme renale, nematode known as "giant kidney worm", which affects various species of wild and domestic carnivores. The Pampas fox (Lycalopex gymnocercus) is the most abundant wild canid from South America. This wild canid inhabits natural, peri-urban and highly modified by agricultural activities areas. The aim of this study was to describe a case of dioctophymosis in a Pampas fox. In May 2022, a Pampas fox wandering in a peri-urban area around the city of La Plata, Buenos Aires (57°57'16.3 W; 34°55'17.22 S), Argentina, was rescued and housed at the Estación de Cría de Animales Silvestres (ECAS) to assess its health status and subsequent relocation. The animal died suddenly 72 hours after rescue and an abbreviated necropsy examination was performed. Pathological findings included the presence of an adult female specimen of Dioctophyme renale, 40 cm long and 0.6-0.7 cm in diameter, accompanied by a marked reduction of the right kidney parenchyma and considerable enlargement of the left kidney. Other findings were diffuse haemorrhages in the mesentery, a greyish-white area in the right lateral lobe of the liver and a yellowish-white, fatty-looking mass 0.5 cm in diameter at the base of the heart. The rest of the organs showed no lesions. The identification of the nematode was based on its morphological characteristics: size, characteristic red colour and small mouth without lips, surrounded by six papillae on the anterior extremity. In addition, the transversely striated cuticle and obtuse caudal limb with terminal anus were observed. Dioctophyme renale has been reported in several countries in different mammal species. This is the first record in a Pampas fox. This finding was recorded in an endemic area for this parasitosis in domestic dogs. Further studies should assess the contribution of this species to the dynamics of Dioctophyme renale.