The role of intramammary pathogens in dairy goats

Pathogens involved in goats mastitis and the strategies for their prevention and control are revised. Staphylococcus aureus is an important clinical pathogen but coagulase negative staphylococci (CNS) are the most prevalent in subclinical mastitis (more than 50% in most of the studies). Incorrect milking machine routines are usually involved in high prevalence of CNS. Contagious agalactia (CA) is an important disease affecting goats and antibiotic treatment and vaccination are controversial. Streptococci and Gram negative bacilli (GNB) are major intramammary pathogens but not very frequent in goats and are associated with poor hygienic conditions in housing and the milking parlour. Because of the lower prevalence of GNB mastitis in goats than cows, physiological and environmental factors protecting goats from GNB infection are discussed. Other pathogens affecting the caprine mammary gland are also discussed, such as Arcanobacterium pyogenes, Bacillus spp., Clostridium perfringens, Nocardia asteroides and lentiviruses (caprine arthritis-encephalitis virus).