Review: Tail lesions in dairy cows - a summary of what's new about the old

This review summarises the most relevant literature on tail necrosis in cattle, with a particular focus on dairy cows. Tail inflammation and necrosis are widespread phenomena that have been recognised as affecting entire herds since the early 1970s. Initial reports from various European countries described a new health issue affecting beef cattle, with prevalence rates reaching 100% and severely impairing animal welfare. A review of the literature shows that, since these initial reports, the focus has remained relatively consistent on internal causes relating to feed-related rumen acidosis in beef cattle, since the clinical manifestation is pathomorphologically similar to microcirculatory disorders in the tail tip. In addition to internal causes, the review summarises other factors that have been discussed, such as housing conditions (e.g. slatted floors), stocking density, and trauma. While reports of tail injuries in cows are common, with dislocated vertebrae in the middle section of the tail often being described, lesions at the tip of the tail have become increasingly prevalent in recent literature. Comparing these lesions with those described in beef cattle in the context of tail inflammation and necrosis suggests that they are likely to represent the same phenomenon despite different terminology being used for their description. Although the aetiology of tail inflammation and necrosis is diverse and often remains to be elucidated, the incidence of the clinically diagnosed tail lesions is increasingly reported in dairy cows as well as in beef cattle. Given the animal welfare implications of this diagnosis, various hypotheses regarding the pathogenesis and predisposing factors for tail lesions are discussed, and suggestions for intervention strategies are addressed.