Mastitis in sheep: a disease to be taken seriously

Abstract

Mastitis is the inflammation of the mammary gland, whether infectious or not. Nonetheless, bacteria are the main aetiological agents of this disease. A diversity of bacterial genera and species has been reported to cause mastitis. Mastitis in sheep are the source of serious economic losses due to mortality, premature culling, decreased lamb growth and survival, and reduced milk production. Other negative outcomes of sheep mastitis include the hampering of cheese ripening and decrease in its quality. Mastitis control in sheep has been somehow neglected, as clinical mastitis prevalence is generally low. Notwithstanding, subclinical mastitis prevalence may be extremely high, resulting in decreased milk yield and reduced milk quality economically impairing milk farmers and cheese producers. Mastitis control has been based on the use of antimicrobials exerting a selective pressure on resistant strains and enhancing the transfer of resistance genes from mastitis causing pathogens to bacteria belonging to the human microbiota. Farmers and veterinarians should permanently be aware of this Public Health concern. The present chapter addresses a comprehensive review of sheep mastitis. It covers up-to-date reports on aetiology and epidemiology, important features of the disease, such as pathogenesis, clinical signs and diagnosis, and the current knowledge on treatment and prophylactic strategies for mastitis control. With the concern of safeguarding human and animal health, for one health protection, alternative approaches to antimicrobials for the control of mastitis in sheep are highlighted.