Prototheca bovis has been linked to mastitis since 1952. However, within the last five years, its prevalence has significantly increased. It is a non-photosynthetic, yeast-like microalgae thrives in high humidity and plentiful damp organic matter.
Similar to Staph aureus and mycoplasma, Prototheca is hard to detect, has no known cure and is contagious by intermittently shedding from cow to cow. Reservoirs include, but are not limited to soil, holding areas, waterers, forage, bedding materials, cattle feces to milkhouse floors, teat dip containers, milking parlor wash water and other cow-barn surroundings.
Source: Dairy Herd Management, October 28, 2022. Link.
Prototheca bovis mastitis has shown resistance to a wide variety of pharmacological products, including antibiotics. Because this mastitis is incurable, infected cows should clearly be identified and milked last in the milking order until they can be culled.
INSIGHTS: Note that early and mild inflammation signs of Prototheca may escape producers. Telling them what to watch for is important, as is reinforcing cleaning and disinfection protocols.