4. Contagious Mastitis
Dr. Keller then asks to see the herd treatment records that Oliver maintains. The records indicate that at least 25% of the herd was treated for clinical mastitis at least once during each lactation period. Dr. Keller explains that a 25% rate of clinical mastitis is typical for most dairy farms, and indicates that this herd’s problem with high SCC is likely due to subclinical mastitis and not due to excessive clinical mastitis.