Welly boots and spreadsheets: A rough guide to production animal medicine for medical writers There have been countless columns written about “herd immunity” during and since the COVID-19 pandemic. But what does it take to write about a real-life herd? As in a herd of domestic cattle, sheep, llama or buffalo? In this article, large-animal-veterinarian-turned medical writer Rhona Fraser draws on her experience as a dairy practitioner in New Zealand. She highlights the aspects of production animal health that are different from those of human and companion animal practice that should be reflected in all medical communications based on these species.