Cylicospirura felineus in Puma (Herpailurus yagouaroundi) in southern Brazil - Macroscopic and microscopic aspects.

ABSTRACT

Parasites of the Cylicospirura genus are known to affect domestic and wild carnivores by causing the formation of nodules within the gastric mucosa and pyloric region of parasitized animals. C. felineus is a specimen of this genus that has been reported in Brazil in animal species such as Leopardus geoffroyi and Puma concolor. However, as far as the authors of the present study are aware, reports of C. felineus in jaguarundis (Puma yagouaroundi) do not yet exist. This wild feline species native to the Americas is found only in a few countries - and it is possibly extinct in others, such as the United States. In Brazil, the P. yagouaroundi species is classified as vulnerable by government environmental agencies. Consequently, identifying the diseases and their relevance to this species is of utmost importance for P. yagouaroundi's preservation. This study aims to describe the histopathological lesions found in jaguarundis parasitized by the genus Cylicospirura, and to identify the parasitic species observed in these animals. Eight specimens of P. yagouaroundi necropsied between 2010 and 2020 in the Laboratory of Veterinary Pathology of the Federal University of Paraná (UFPR) in Palotina, Brazil, were studied. Seven specimens were wildlife roadkills, and one was from the Municipal Zoo of Cascavel, Paraná, Brazil. Seven of the necropsied animals presented - in the greater curvature of the stomach, near the cardia - one or more parasitic nodules of 0.5 to 3.0 cm in diameter that contained several intralesional reddish filiform parasites. Histologically, these nodules were characterized as transmural parasitic granulomas surrounded by reaction with deposition of dense connective tissue. The parasitological evaluations by light and scanning electron microscopy identified morphological C. felineus' characteristics through the presence of unequal spicules in males, the position of the vulva, and location of the pedunculated papillae. Despite the gastric lesion caused by the parasite, the apparent low pathogenicity to the gastrointestinal system of the evaluated animals, massive infections or large nodules can lead to death - other members of the Spirocercidae family are known to cause organ rupture, esophageal obstructions, and mesenchymal neoplasms. Therefore, C. felineus should be included in the list of gastric parasites with pathogenic potential in the species P. yagouaroundi.