# Clinical form of babesiosis caused by Babesia canis in Polish foxes (Vulpes vulpes)

## TL;DR

This paper reports the first cases of clinical babesiosis in Polish foxes caused by Babesia canis, suggesting foxes may act as a new reservoir for this parasite.

## Contribution

The study presents the first documented clinical cases of Babesia canis infection in red foxes in Poland.

## Key findings

- Four foxes showed clinical signs of babesiosis, including apathy, anemia, and brown urine.
- PCR and sequencing confirmed Babesia canis infection in all four foxes.
- Foxes may serve as a new reservoir for B. canis in areas with D. reticulatus ticks.

## Abstract

The red fox (Vulpes vulpes) is known to be a reservoir host of various vector-borne protozoan parasites. However, the impact of infections caused by Babesia canis on the health status of the red fox remains unknown, and research on this topic conducted on fox populations in Poland and worldwide has been fragmentary. It is known that these animals can become infected with Babesia canis, but it is unclear whether a clinical form of the disease can develop in them. This study aimed to present for the first time the cases of clinical babesiosis in foxes in Poland. The observations covered four foxes aged 3–6 years with apathy, anemia, brown color of urine and thrombocytopenia. The PCR and sequencing results confirmed that all the animals had been infected with Babesia canis protozoa. The diagnosis of clinical cases of babesiosis due to B. canis in foxes from this region of Europe suggests a contribution of red foxes to the establishment of this animal species as a new reservoir of B. canis. These animals may play a role as a host for B. canis, and previously unexposed red fox populations may be more prone to infection in areas colonized by D. reticulatus.