This study aimed to assess the prevalence and seasonal distribution of respiratory pathogens in cattle in the UK, using clinical samples submitted for laboratory PCR analysis. Data were retrospectively collected from a central laboratory in Scotland, comprising 407 pooled clinical samples provided by 95 veterinary practices across the UK between November 2020 and September 2022. Analyses included spatial mapping using choropleth techniques, chi-squared tests, and both Poisson and logistic regression models to explore associations. Analysis showed that 77.6% of samples contained multiple bacterial species, while 17.7% harbored more than one virus. The odds of infection with certain respiratory pathogens were significantly lower in the warmer months (March–August) compared with autumn and winter (September–February). Poisson regression indicated modest but significant univariable associations between weekly age and both total viral load (coefficient = ‒0.01, SE = 0.004, 95% CI = ‒0.02 to ‒0.003) and total pathogen count (coefficient = ‒0.005, SE = 0.002, 95% CI = ‒0.008 to ‒0.002). This study is inherently limited by its reliance on a single laboratory’s submissions, introducing potential sampling bias, and by the retrospective nature of the analysis. Most bovine respiratory disease (BRD) cases involved multiple pathogens, with bovine coronavirus—typically not considered a major BRD contributor in the UK—being frequently detected.
