Mastitis caused by Prototheca zopfii in a Hungarian dairy herd

Abstract

Mastitis is one of the diseases resulting in the greatest economic losses in dairy herds. It is a polyetiological, polyfactortial disease in dairy cows. The most frequent pathogens causing mastitis are Staphylococcus and Streptococcus spp as well as E.coli. In recent years however another pathogen has been seen to be an increasing cause of mastitis. This is the unicellular alga Prototheca zopfii. It occurs worldwide in tropical and temperate climates and appears sporadically in therapy resistant form. However, in poorly managed dairy herds it may be endemic, causing serious economic losses as a result of decreased milk quality and quantity and culling of infected animals. Prototheca zopfii is classed as an ‘in between’ pathogen and its presence indicates a low level of milking and housing hygiene at farm level. Prototheca zopfii is impossible to diagnose outside the laboratory and because few clinical signs are evident in diseased cows infection spreads undetected in dairy herds. To date there is no antibiotic available to treat this condition as it is extremely resistant so the only option available to farmers who want to eradicate this disease is culling. Milking parlour hygiene, hygienic milking and cleanliness of feeding passages and walking ramps remain the main methods for preventing this disease, as with any environmental mastitis pathogen.