# Carcass-Based Surveillance of Amphibian Herpesviruses, Ranaviruses and Batrachochytrium dendrobatidis in Schleswig-Holstein, Northern Germany

## TL;DR

This study surveyed dead amphibians in Germany to detect viruses like herpesviruses and Bd, finding evidence of herpesviruses without visible symptoms.

## Contribution

The study confirms the presence of amphibian herpesviruses in northern Germany using carcass-based surveillance and highlights its limitations.

## Key findings

- BfHV1 was detected in nearly half of Bufo bufo (common toads) and RaHV3 in 23.6% of Rana temporaria (common frogs).
- Bd was found in one Bufo bufo, but ranaviruses were not detected in any samples.
- No visible or histological lesions were observed despite herpesvirus presence, suggesting possible asymptomatic infections.

## Abstract

Amphibian populations are undergoing dramatic global declines, with infectious diseases recognized as major contributors. While chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), and disease caused by ranaviruses are well known, herpesviruses in amphibians remain comparatively neglected. We conducted a passive survey using carcasses collected between 2022 and 2025 in Schleswig-Holstein, northern Germany. Dead amphibians (n = 187) were dissected. Skin, kidney, liver, and brain samples were screened for Bd, ranaviruses, bufonid herpesvirus 1 (BfHV1), and ranid herpesvirus 3 (RaHV3) by PCR. BfHV1 was detected in nearly half of the Bufo bufo (common toads; 48.6%), while RaHV3 was identified in 23.6% of the Rana temporaria (common frogs) examined. Bd was detected in a single B. bufo, while ranaviruses were not detected. BfHV1 was present in skin, liver, kidney, and brain samples, whereas RaHV3 was detected exclusively in skin samples. No macroscopical or histological lesions characteristic of herpesviruses or Bd were found. However, the carcass-based approach frequently limited detailed examination due to compromised sample quality. Our findings confirm the presence of amphibian herpesviruses (BfHV1 and RaHV3) in the region without associated lesions, raising questions about their potential to cause systemic infections. Furthermore, our results highlight the limitations of carcass-based surveillance and underscore the need for complementary diagnostic approaches, such as immunohistochemistry and meta-omics.