Which of the following is a common indicator of mastitis in a dairy cow's milk?

• A. Milk clots and thickens without SCC changes
• B. Elevated somatic cell count (SCC) and visible abnormalities
• C. Lower milk yield is the only sign
• D. Color change to blue indicates infection

Answer: (B)

Mastitis triggers an immune response in the udder, causing an increase in somatic cells in the milk and inflammation that changes how the milk looks. An elevated somatic cell count is a reliable, direct signal of intramammary infection, and visible changes in the milk—such as clots, thickening, or discoloration—reflect that inflammation. Together, these two signs provide the clearest indication that mastitis is present. Relying on milk yield alone can miss subclinical infections, a blue color change isn’t a recognized sign of infection, and clots or thickening can occur without SCC changes, so they’re not as dependable on their own.