Bovine mastitis, which affects cows, leads to reduced milk production and can be fatal if left untreated. The USDA National Animal Health Monitoring System has reported cases in 99.7% of all dairy operations in the U.S., making it the most prevalent disease on dairy farms. Bovine mastitis, which affects cows, leads to reduced milk production and can be fatal if left untreated. The USDA National Animal Health Monitoring System has reported cases in 99.7% of all dairy operations in the U.S., making it the most prevalent disease on dairy farms. Cell & Microbiology Agriculture Phys.org – latest science and technology news stories