Treating mastitis and responsible antibiotic use

Defining a mastitis problem and developing an effective treatment plan often requires a team approach involving veterinarians, milking machine technicians, and other dairy advisors. Once the issue has been investigated and clearly identified, the team can create a plan with you that works for the farm. Discuss technote 4 with your vet with regards to finding, treating and recording clinical cases.

Have a procedure for treating mastitis on your farm

Once mastitis has been detected, there should be a clear procedure for treatment. This may include:

1: Using MRS T – A system to clearly mark cows that have been treated:

M – Mark - when you have decided a cow needs antibiotic treatment.
R – Record - cow number and treatment details. All treatments must be recorded.
S – Separate - from the milking herd.
T – Treat - refer to farm treatment plan for most suitable treatment.

2. Collecting milk samples for culture

Taking a sterile milk sample for culture is recommended especially when a herd problem emerges, when there are more clinical cases than is acceptable or when somatic cell count (SCC) is rising.

Why milk sample?

Taking milk samples for culture can help identify the bacteria causing mastitis and support better treatment decisions. Some infections are more likely to benefit from antibiotics, while others may recover without them and can be managed with supportive care.

Using culture results helps target treatment, reduce unnecessary antibiotic use, and support good animal health outcomes. On-farm culture systems can provide results quickly, helping farmers and their vets make timely, informed decisions about the best course of action.

Non-antibiotic ways to manage mastitis treatment

• Frequent stripping/milking out: Regularly milk out the affected quarter to remove infected milk and toxins. This helps reduce pressure and discomfort but is less effective than antibiotics for curing infection.
• Anti-inflammatories: Non-steroidal anti-inflammatory drugs (NSAIDs) can reduce inflammation, pain, and fever. These are supportive treatments and may be especially useful in severe or toxic cases.
• Effective teat spray protocols: focus on the correct coverage and preparation of the teat spray solution. Regular checks of your equipment and mixing process can ensure that the spraying is effective and helps avoid increases in mastitis infections.
• Effective teat care protocols: Regular teat scoring and monitoring to prevent teat damage is essential to preventing mastitis.
• Intravenous or oral fluids: For cows with toxic mastitis or those showing signs of shock, large volumes of fluids (IV or oral) can improve survival chances.
• Drying off the affected quarter: In cases where a quarter does not respond to treatment, drying off that quarter can be considered to prevent further infection and discomfort.
• Culling: For cows with persistent or chronic infections that do not respond to other measures, culling may be the best option to protect herd health.

It's important to note that while these methods can support recovery and cow welfare, they are less effective than antibiotics at achieving a bacteriological cure. Always consult your vet before making treatment decisions for mastitis. Our healthy udder guide has some tips for minimising mastitis and how to treat it.

Podcast: Mastering mastitis

For practical advice for managing mastitis in your dairy herd, listen to the podcast with Mike Shallcrass, Fonterra’s Veterinary programme manager, and Jane Lacy-Hulbert, DairyNZ Senior scientist, as they discuss and share practical tips on monitoring, managing, and minimising mastitis.

Treat mastitis with antibiotics only when necessary

Antibiotics are a valuable tool for managing mastitis and other bacterial diseases in dairy cows. But, as with humans, overuse of antibiotics in animals can lead to a greater risk of bacteria developing resistance to specific antibiotics. By using antibiotics in a responsible way, under veterinary guidance, we can minimise this risk.

What's the issue with antibiotics?

Internationally, there are concerns about the use of antibiotics in food-producing animals, especially those antibiotics that are critical to human health.

When bacteria develop resistance, this may:

• Reduce the ability of antibiotics to cure infections in both animals and humans.
• Require the use of different drugs.
• Increase the risk of spreading resistant bacteria to other animals, farms or humans.

Managing antibiotic use on NZ dairy farms

Responsible use of antibiotics is best achieved by farmers meeting regularly with their vet to develop a herd animal health plan. This may involve a milk quality consultation, to review mastitis and milk quality management.

It will involve a restricted veterinary medicine (RVM) review, to identify the types of products allowed on farm, and situations when these can be used. Many veterinarians are using a “traffic light” approach to support responsible use of antimicrobials on farm.

This may impact the types of products recommended to treat clinical cases of mastitis. This method has altered the way we use antibiotics when we dry cows off. For more details, see the NZ Veterinary Association (NZVA) publication, Antibiotic judicious use guidelines.

Antibiotic use in other countries

Several countries are moving away from routine antibiotic use for mastitis. The Netherlands halved dry cow antibiotic use after banning whole herd treatment, while also reducing mastitis cases. Scandinavia requires confirmed infection before treatment, and the United Kingdom, France, and Belgium have set reduction targets. Work with your veterinarian to set antibiotic reduction targets for your farm and reduce the risk of resistance.