## 1 Introduction  
In the past, sheep and goat farming has been considered as an \"inferior\" form of animal husbandry and a sign of economic underdevelopment. This was especially true for the Mediterranean countries. The main reasons for this were that in large areas of these countries sheep and goat farming was an important occupation of the poorest part of the rural populations and the simplistic methods by which these animals were handled. Practically most of the farmers were herding their animals in a manner much similar to that in classical antiquity. Nevertheless, things have changed during the last two decades [1; 2; 3; 4]. The markets acknowledged the organoletic and the nutritional value of the sheep and goat's dairy products and the demand for these products increased [3; 5; 6; 7; 8]. Many of these products have received the characterization PDO (Protected Designation of Origin) which adds commercial value [1; 7; 10]. The governments tried, through subsidiations and other economic means, to support the farmers, and the dairy industry has also invested on these farms. It is not a surprise that the landscape in sheep and goat farming has changed dramatically. New farms have emerged with better facilities, automatization, genetically improved livestock and with well implemented nutritional practices. On the other hand, in mountainous and remote areas many farms still function in a traditional manner and thus a phenomenon of two-speed farming has been observed ([11] & personal data). The impact of this differentiation on various parameters that determine the quality and the safety of the milk has not been thoroughly investigated. Subclinical mastitisis the most prevalent health ailment in these herds. The disease although has no clinical signs but is of great importance due to the reduction of the milk yield up to 8% per animal as well as the technological defects of the final product [12]. There is a consensus in scientific literature that the Coagulase Negative _Staphylococci_ (CNS) are among the main causative agents of subclinical mastitisitis in small ruminants and account for more than 65% of cases [13, 14]. However, quite a few researchers agree that some CNS can play a protective role to the health of the udder [15, 16]. This effect is probably strain and species specific and wherever it is observed one should expect a reduction in the use and consequently in the misuse of antibiotics, an aspect neither clearly understood nor investigated. The misuse of antibiotics in some farms is a fact. As [PERSON] (2014) [17] puts it, most medicines are registered for cows and relatively few are registered for mastitis treatment in small ruminants, yet most veterinarians use these drugs licensed for bovines, empirically in goats and sheep. This results to deviating dosage issues (overdose or underdose), a problematic therapeutic efficacy and an unknown withdrawal period [17]. In some countries the same active substance (usually a \(\beta\)-lactam) is used not only in the treatment of mastitis but also in many other clinical ailments (e.g., diarrhea, skin lesions, etc.). These conditions lead to residues of antibiotics in the milk. Residues of antibiotics are not affected by the thermal treatment of the milk. Neither the heat treatment nor any other process of the milk decomposes or deactivates the residues and therefore they accumulate in the food chain and reach the consumer causing allergies, toxicities, cancer, mutagenesis and antimicrobial resistance to the intestinal microbiome [18, 19]. These residues cause also significant technological failures with consequent financial loses in the dairy industry and particularly in the fermentation processes [20]. According to the EU legislation, milk containing residues of antibiotics should be discarded as category 2 ABP (Animal by-products) [21, 22]. It follows that it is of utmost importance to detect the residues and the best place to undertake that is at the production site, in the milk of the bulk tank of the farm, before the milk reaches the dairy.