Dairy cows: controlling contagious mastitis 

Mastitis treatment and control is one of the highest costs to the UK dairy industry and has a major impact on dairy cow welfare. Udder infections can be picked up from the environment or less commonly transmitted from cow to cow, i.e. contagious transmission. 

Recent analysis shows that as an overall herd pattern, contagious transmission is much less common than infection from the environment.*  

Contagious mastitis-causing bacteria typically live on the cow’s udder and skin of the teats. In contagious transmission, this bacteria transfers from the affected cow or quarter to healthy cows or quarters during milking. They adhere easily to the skin, colonising the teat end and then growing into the teat canal, where infection occurs. 

This set of pages looks at the measures you can take to prevent the spread of contagious mastitis. For more information, find out about our QuarterPro programme, visit the Dairy Mastitis Control Plan and use our Mastitis Pattern Analysis Tool (MPAT) for a simple, automated way of understanding transmission patterns in your herd. 

*In 2018, the AHDB Dairy Sentinel Herds group found that contagious mastitis patterns affected only 8% of herds, with the rest having mainly environmental mastitis patterns. 

Mastitis can be caused by numerous different types of bacteria, also known as pathogens. Find out about the most common types of bacteria responsible for contagious mastitis in UK dairy herds. 

Find out about the measures you can take to reduce the risk of mastitis spreading through your herd, including how to reduce the number of cases in the herd and the importance of clearly marking affected cows. 

We look at antibiotic treatment for contagious mastitis, giving you practical advice on effectively identifying and treating mastitis in milking cows. 

The California Milk Test (CMT), also known as the California Mastitis Test, can be used to detect which quarters are likely to be affected and targeted for treatment with intramammary antibiotics. 

With chronic mastitis, it’s important to understand which cows to cull to lessen the risk to the rest of the herd. Read about this and other measures you can take to prevent infection spread. 

Post-milking teat disinfection isn’t just an essential part of a good milking routine; it’s critical to controlling contagious mastitis. Read our tips for the best possible results. 

Find out how to keep milking machinery running smoothly and how to ensure your milking routine is optimised to minimise the risk of contagious mastitis spread. 

If you would like to order a hard copy of the Control of contagious mastitis guide or Control of heifer mastitis please contact: publications@ahdb.org.uk or telephone: 0247 799 0069