3/3/2026: 

Our new article “Campylobacter bilis caused spotty liver syndrome in laying hens in the Netherlands” was recently published in Veterinary Quarterly. Spotty liver disease is a condition observed worldwide in laying hens, particularly in free-range systems. The main causative agent reported is Campylobacter hepaticus.

Since 2019, we have been able to culture the causative agent of spotty liver disease from liver and bile samples from chickens after necropsy. In this paper, we report the detection of C. bilis in clinical cases of spotty liver disease in the Netherlands. The species was first described in 2022, based on a sample collected in 2018. C. bilis is closely related to C. hepaticus. While C. hepaticus is widely reported across multiple continents, C. bilis has so far only been documented in Australia (since 2018) and the USA (since 2025).

We, in collaboration with Miriam Koene (WBVR), confirmed the presence of C. bilis in Dutch clinical cases from 2020 using both whole genome sequencing and MALDI TOF MS. The pathological lesions were undistinguishable compared to lesions caused by C. hepaticus.

Our findings suggest that C. bilis may be globally more widespread than previously assumed, and this could have implications for treatment decisions and prevention strategies.

Read the full article in Veterinary Quarterly

Authors: Erik van Engelen, Miriam Koene (WBVR), Robert Jan Molenaar, Annet Heuvelink