Association Between <i>Escherichia coli</i> Mastitis and Acute Laminitis in Dairy Cows

The objective of this retrospective case-control study was to examine the relationship between <i>E. coli</i>-induced mastitis and acute laminitis in dairy cows. Correspondingly, the medical records of 93 cows diagnosed with <i>E. coli</i> mastitis between 2012 and 2023 were analysed. The cows were categorised into three groups: (1) cows with mastitis scores of 1 or 2 without signs of acute laminitis; (2) cows with a mastitis score of 3 without signs of acute laminitis; (3) cows with a mastitis score of 3 and exhibiting symptoms of acute laminitis. Out of the 93 cows with <i>E. coli</i> mastitis, 19 were assigned to group 1 (20.4%), 46 to group 2 (49.5%), and 28 to group 3 (30.1%). A total of 74 cows (79.6%) scored 3 for mastitis, but 28 cows (37.8%) were also diagnosed with acute laminitis. A higher mastitis score was significantly associated with a higher incidence of acute laminitis (<i>p</i> = 0.0004). <i>E. coli</i> mastitis showed a higher incidence in parity ≥ 3 (73.3% to 78.6%) and occurred in cows of all three groups mainly during the first third of lactation (53.6% to 75.6%). Cows in group 1 had a median survival time of 512 days, while for cows in groups 2 and 3, these values were 93 and 178 days, respectively. Regarding survival times, only a trend but no statistically significant difference (<i>p</i> = 0.221) was found among the cows in the three groups. This could possibly be explained by the fact that additional comorbidities were diagnosed in 53.6% to 65.2% of the cows from all three groups. It is concluded that cows with severe coliform mastitis have a higher risk of developing acute laminitis, and that a thorough clinical examination of the claws should always be performed to avoid overlooking acute laminitis, which accompanied the <i>E. coli</i> mastitis in approximately 38% of cases.