<i>Campylobacter bilis</i> caused spotty liver syndrome in laying hens in the Netherlands

Spotty liver disease in laying hens can be caused by <i>Campylobacter hepaticus</i> or by <i>Campylobacter bilis</i>. While <i>C. hepaticus</i> is widely distributed around the world, <i>C. bilis</i> has thus far only been documented in Australia and the USA. We investigated five outbreaks of spotty liver disease in laying hens in the Netherlands. In November 2020 <i>C. bilis</i> was cultured as the causal agent of the outbreak on one of these farms, while <i>C. hepaticus</i> was cultured from hens from the four other farms. Clinical and pathological features were indistinguishable, but MALDI-TOF and WGS identified these species unambiguously. To our knowledge, this is the first report of <i>C. bilis</i> outside Oceania and the USA.