Although it is widely acknowledged that the excessive use of specific drugs within a farm indicate the presence of management or health issues, it can also be hypothesized that the use of certain drugs (e.g., local antibiotics, anti-inflammatories) may mask the presence of other health problems (e.g. mastitis, lameness) that impair animal welfare. The aim of this preliminary study was to investigate the potential relationship between the welfare of dairy cows and the use of drugs. Inspections were carried out in 6 free-stall dairy farms located in Northern Italy (average size: 292 heads, 115 lactating cows). In each farm, the welfare of the lactating cows was assessed using the Welfare Quality protocol, and data on drug use during the year before the visit was collected from the farm register. Descriptive analysis showed that antibiotics were by far the most commonly used drugs (ranging between 30 and 100% of treatments in the different farms). Pearson correlation coefficients highlighted the presence of positive relationships between the number of animals and 1) treatments/head/year (r=0.8496, P=0.032), 2) antibiotics/head/year (r=0.8325, P=0.038), and 3) systemically administered antibiotics (r=0.8427, P=0.035). These results suggest an increased challenge in preserving the animals\u2019 health in larger farms, probably due to a relative farmhand shortage (numerically higher animals:stockpeople ratio) observed in these farms. In one farm, which showed the lowest number of intramammary antibiotic treatments, a high somatic cell count was reported, likely indicating that the use of these drugs might mask the presence of mammary infections thus leading to an overestimation of the cows\u2019 welfare level. Further research on a wider number of farms is needed, but these preliminary results indicate that drug use should be included in the assessment for a more holistic approach to animal welfare evaluation
