Toxocariasis and toxascariasis in wild felids of southwestern Primorsky Krai

Long-term parasitological studies in southwestern Primorsky Krai reveal near-identical helminth communities in the Amur tiger and Far Eastern leopard, with Toxocara cati representing the dominant parasite species, albeit with fluctuating prevalence rates. We provide morphological characterization of fourth-stage larvae for both T. leonina and T. cati, along with developmental observations of T. leonina to adulthood. During 2018 summer surveys in protected areas, cyst-encapsulated third-stage larvae morphologically and morphometrically consistent with T. cati and T. leonina were identified in the hepatic serosa of two rodent species serving as intermediate hosts: the Korean field mouse and striped field mouse. The paper provides a morphological description of the larvae. Epidemiological analysis demonstrates that Amur tigers and Far Eastern leopards acquire toxascariasis primarily during peak rodent population cycles (from 3 to 4 year intervals), while the Amur forest cat maintains persistent toxocariasis infections throughout its lifespan.