Mycoplasma Mastitis
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EmailA unique pathogen that presents challenges for dairy farmers.
Many bacterial species can cause mastitis on dairy farms, but some pathogens are more difficult to detect, control and prevent. Unlike other mastitis pathogens such as E. Coli and Klebsiella, Mycoplasma species have several unique characteristics that make them uniquely challenging.
Mycoplasma are difficult to identify using on-farm culture
Many dairy farms use on-farm culturing as a mastitis detection strategy. However, Mycoplasma species require specialized nutrients that most standard bacteriological media do not supply. Additionally, Mycoplasma species take longer to appear, and some can take up to 28 days to grow visible colonies. Even then, these colonies can be easily obscured by other faster-growing species if there is any contamination. Alternate diagnostic methods, such as PCR and bulk tank testing, are recommended as part of a mastitis control program.
Mycoplasma can infect both calves and adult cows
Beyond causing infections in adult dairy cows, Mycoplasma can spread to calves through infected colostrum or by direct respiratory contact. Mycoplasma can cause middle and inner ear infections in calves, leading to a head tilt or unilateral drooping ear. This means that if you detect Mycoplasma on your dairy farm, your population at risk isn’t just your lactating cows, it’s the entire herd!
Beta-lactam antibiotics are completely ineffective
Penicillin, amoxicillin and cephalosporin antibiotics work by disrupting bacterial cell walls, either by preventing repair, causing cell rupture or binding to enzymes necessary for cell wall integrity. However, Mycoplasma have no cell walls, so these antibiotics are completely useless. Most Mycoplasma infections do not spontaneously resolve, so these infections often become chronic and subclinical with intermittent pathogen shedding. If a cow has a confirmed case of Mycoplasma mastitis, then segregation or culling should be considered to protect the rest of the herd.
Mycoplasma spreads through the bloodstream
While some mastitis pathogens can cause secondary infections, Mycoplasma can enter the bloodstream and travel through the body. While other mastitis pathogens typically infect one quarter of the udder at a time after entering the teat canal, Mycoplasma can travel to multiple quarters through the bloodstream, causing multi-quarter mastitis at the same time. Beyond mastitis, Mycoplasma can travel through the bloodstream and cause many other symptoms, including polyarthritis, bovine respiratory disease, chronic non-responsive pneumonia and urogenital tract infections.
Uncontrolled Mycoplasma infections are expensive
Several studies have estimated that the costs of uncontrolled Mycoplama exceed $100 million per year on American dairy farms. Many Mycoplasma mastitis infections are subclinical and are characterized by a persistent decrease in milk yield. Recent research estimates that cows with mastitis caused by Mycoplasma lose 6.5 to 7 lbs. of milk production per day. Over the course of a lactation, this represents a real economic loss for a dairy farm.
Interested in learning more about Mycoplasma on dairy farms? Go to YouTube.com @topmilkquality to view the video series on Mycoplasma as well as many other videos on mastitis, antibiotic stewardship, and milk quality. Pamela Ruegg’s website, topmilk.msu.edu also contains mastitis resources for dairy farmers.