# Identification of Hydatigera Species in Wildcats (Felis silvestris) from Central Spain

## TL;DR

This study identifies two new tapeworm species in wildcats from central Spain using DNA methods and develops a tool to distinguish them.

## Contribution

The study reports the first detection of two Hydatigera species in Spanish wildcats and introduces a new molecular tool for their identification.

## Key findings

- 73% of wildcats in central Spain were infected with Hydatigera tapeworms.
- Two Hydatigera species were identified for the first time in Spanish wildcats.
- A new multiplex PCR test was developed to differentiate between the species.

## Abstract

The European wildcat (Felis silvestris) is a wild feline found in various regions of Spain, with a diet primarily consisting of mice and rabbits. These animals can become infected with intestinal parasites, such as tapeworms of the genus Hydatigera. Some of these parasites are very difficult to distinguish under a microscope but can be identified using DNA-based methods. In this study, 26 road-killed wildcats from central Spain were examined, and 73% were found to be infected with Hydatigera tapeworms. Using molecular tools, researchers identified two different Hydatigera species never before reported in Spanish wildcats. A rapid genetic test was also developed to differentiate them. This study extends the known geographical range of the species in the H. taeniaeformis complex (Hydatigera kamiyai and an unnamed Hydatigera sp.) in Europe and provides a reliable molecular tool for identifying them, which is essential for further epidemiological studies.

The European wildcat (Felis silvestris) is a mesocarnivore widely distributed across Europe, with populations in the Iberian Peninsula experiencing decline due to habitat fragmentation, hybridization with domestic cats, and anthropogenic factors. Among the parasites commonly found in wildcats are cestodes of the genus Hydatigera, which includes cryptic species within the Hydatigera taeniaeformis complex. This study aimed to identify Hydatigera species within this complex infecting wildcats in central Spain using both morphological and molecular methods. A total of 26 road-killed wildcats were collected between 2021 and 2023 from Castilla and León and Castilla-La Mancha. Cestodes were recovered from 73% of individuals, yielding a total of 240 Hydatigera specimens. Molecular analysis of the mitochondrial cox1 gene and a newly developed multiplex PCR targeting cox1, cytb and nad4 genes enabled differentiation between Hydatigera kamiyai and European Hydatigera sp., confirming their presence in definitive hosts in Spain for the first time. Mixed infections were detected in 60% of infected wildcats. The high prevalence and parasite load observed highlight the role of rodents in the transmission cycle. This study expands the known distribution of the H. taeniaeformis complex species in Europe and provides a reliable molecular tool for their identification, essential for further epidemiological investigations.