Clinical Presentation of Tail Inflammation and Necrosis in Dairy Cows: A Possible Manifestation of Bovine Inflammation and Necrosis Syndrome (BINS)

Tail inflammation and necrosis in dairy cows are increasingly reported, yet the early stages of their development and dynamics remain unclear. We conducted a longitudinal study to characterize the macroscopic pathogenesis of tail lesions throughout the entire lactation period to identify the initial stages and vulnerable phases of lactation. Fifty-one cows were examined weekly. We scored the distal spineless tail for bloody lesions. Change point analysis and first-order Markov chains were used to describe the timing and transitions probabilities. Overall, 60.8% of the cows developed at least one bloody lesion, with 49.0% experiencing lacerations and 25.5% undergoing autoamputation. On average, autoamputation shortened tails by 4.0 cm. Three progression types were identified: laceration with healing and preservation of the tip, autoamputation after laceration and spontaneous autoamputation. Regarding the frequency of occurrence, 65.5% began as bloody lacerations and healed in 93.2% of cases. Of these, 4.0% progressed to autoamputation, 12.7% underwent spontaneous autoamputation from an intact tip. Significant changes in lesion severity occurred in lactation weeks 8 and 40. These patterns are consistent with an endogenous microcirculatory mechanism and support the hypothesis that tail inflammation and necrosis may represent a manifestation of Bovine Inflammation and Necrosis Syndrome.