Dairy cows: Treating mastitis in heifers 

Find out how to treat mastitis in heifers, including what treatments to avoid.  

Treating existing mastitis infections with antibiotics should be viewed as a short-term approach rather than as a method of ‘control’. For longer-term success, it’s important to improve your herd management and put strategies in place to prevent infections. To find out more about prevention, read our page on preventing mastitis in heifers.  

Prompt, effective treatment is important in heifers, as mastitis infections may affect lifetime saleable milk yield. Do a California mastitis test (CMT) on all heifers with a cell count over 200,000 at first recording and discuss the merits of treating infected quarters with your vet.  

A key part of treating summer mastitis is regularly stripping the affected quarter to remove as much affected material as possible.   

Use intramammary antibiotics to treat the bacterial infection in the quarter, and an anti-inflammatory injection to counter the systemic effects of bacterial toxins. Only use an antibiotic injection if the heifer is unwell.  

Antibiotic dry cow therapy will cure existing major pathogen infections when used before the expected calving date, but it should not be used to control mastitis infections in heifers. This is due to the variation in infection pressure between herds, the long withdrawal periods and the importance of prudent use of antibiotics.  

Don’t use injectable antibiotics to control heifer mastitis infections prior to calving. There’s no published evidence to suggest that they improve the chance of a cure or reduce the risk of new infections around the time of calving.  

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