# Babesia Species Detected in Deer from Southwest England

## TL;DR

Babesia parasites were found in deer in Southwest England, suggesting they could spread to livestock and affect farming.

## Contribution

This study identifies Babesia species in wild deer in Southern England for the first time.

## Key findings

- B. divergens/capreoli was detected in both red and fallow deer.
- A Babesia species related to B. odocoilei was found in a single fallow deer.
- The findings suggest wild deer may act as a reservoir for Babesia parasites in Southern England.

## Abstract

Babesia species have been detected in deer across Europe, and deer grazing in the same location as livestock may increase the risk of transmission of species such as the parasite B. divergens. Bovine babesiosis and the cost of treatment increase the economic burden on farmers. To determine the presence of Babesia species in wild deer populations in the counties of Devon and Somerset, Southwest England, blood samples were collected from red (Cervus elaphus) and fallow (Dama dama) deer as part of routine deer management during late 2022 and early 2023. Extracted DNA samples were tested for the presence of piroplasm DNA by polymerase chain reaction. Amplicons were sequenced to identify the species present in samples based on single-nucleotide polymorphisms within the 18S rRNA gene. Two species of Babesia were detected: a B. divergens/capreoli species detected in both red and fallow deer and a Babesia species related to B. odocoilei in a single fallow deer, a species that has been detected in deer across Great Britain. The presence of B. divergens/capreoli in deer blood from these areas provides evidence that wild deer could serve as a reservoir for this parasite within Southern England.