Samples of faeces were taken from 183 healthy pet dogs in a census-based, cross-sectional study in Cheshire; culture methods were used to detect any Campylobacter species and a direct PCR was used to detect Campylobacter upsaliensis. Forty-six of the dogs were positive for C upsaliensis by either culture or direct PCR, giving a prevalence of 25.1 per cent (95 per cent confidence interval [CI] 19.0 to 32.1 per cent). One sample was positive by culture for Campylobacter jejuni (95 per cent CI 0.0 to 3.0 per cent) and one for Campylobacter lari. Multivariable logistic regression identified risk factors for the carriage of C upsaliensis by a dog as: living with another dog that also carried C upsaliensis; being small rather than medium-sized; being less than three years old; living in a household that kept fish; being fed commercial dog treats; and being fed human food titbits, particularly in the dog's bowl.