What form of mastitis is hidden from sight?

Sub-clinical mastitis is often referred to as hidden mastitis because it does not exhibit visible symptoms that can readily be seen on the udder or in the milk. Unlike clinical mastitis, where there are clear signs such as swelling, redness, or abnormal milk, sub-clinical mastitis may present with normal-looking udder and milk, making it difficult for herdsmen to detect without specific testing.

In many cases, sub-clinical mastitis is characterized by elevated somatic cell counts (SCC) in the milk, which indicates inflammation and infection occurring at a level that isn't outwardly observable. This form of mastitis is significant because it can persist undetected in a herd, potentially affecting milk production and quality while also serving as a reservoir for the pathogens that can cause clinical mastitis.

The other forms of mastitis, such as clinical mastitis—where clear symptoms are present, acute mastitis—which can present suddenly with severe symptoms, and severe mastitis—indicating a drastic level of infection and often serious symptoms, are all visible or symptomatic and therefore are not hidden from sight.