Mastitis in Dairy Cattle: On-Farm Diagnostics and Future Perspectives

SIMPLE SUMMARY: Mastitis is one of the most common diseases of the dairy industry and with it brings important economic losses. The most prevalent form of the disease is subclinical mastitis, which leads, in the absence of clinical signs, to decreased milk production, increased somatic cell count, and an increased risk of clinical mastitis during lactation. With the increasing public health concerns for antimicrobial use and its relationship with the development of antimicrobial resistance, nation-specific regulations and general pressure to reduce group-level prophylactic use of antimicrobials have been established. Selective dry therapy reserves antimicrobial treatment for cows or quarters suspected of having an intramammary infection. The treatment is administered after the last milking, while uninfected cows or quarters do not receive antibiotherapy. Since selective dry cow therapy was introduced, different methods of selecting infected cows or quarters have been reported. The aim of this article is to describe the management of mastitis in dairy cows and the main tools for its diagnosis, with a specific focus on on-farm instruments. ABSTRACT: Mastitis is one of the most important diseases in dairy cattle farms, and it can affect the health status of the udder and the quantity and quality of milk yielded. The correct management of mastitis is based both on preventive and treatment action. With the increasing concern for antimicrobial resistance, it is strongly recommended to treat only the mammary quarters presenting intramammary infection. For this reason, a timely and accurate diagnosis is fundamental. The possibility to detect and characterize mastitis directly on farm would be very useful to choose the correct management protocol. Some on-field diagnostic tools are already routinely applied to detect mastitis, such as the California Mastitis Test and on-farm culture. Other instruments are emerging to perform a timely diagnosis and to characterize mastitis, such as Infra-Red Thermography, mammary ultrasound evaluation and blood gas analysis, even if their application still needs to be improved. The main purpose of this article is to present an overview of the methods currently used to control, detect, and characterize mastitis in dairy cows, in order to perform a timely diagnosis and to choose the most appropriate management protocol, with a specific focus on on-farm diagnostic tools.