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Treating for a cure: Extended therapy provides best chance

PD Staff Published on 13 May 2011

Times are changing and treating just to clear up visible mastitis is no longer an acceptable goal. Reaching a complete cure, not just a clinical fix, is critical for producers to meet that demand: improved milk quality, a healthier bottom line and productive cows at maximum performance.

In this roundtable, three veterinarians share their focus on quality milk management and their approach to partner with clients to do more than just clear up abnormal milk. Their passion is on eradicating the pathogen for each mastitis case by using an extended mastitis therapy protocol to achieve a bacteriological cure.



Curing infections the first time around will prevent relapse, reduce retreatment costs and limit the development of chronically infected cows.

Panelists include:
• Garth Millard, Vet Logic Inc. in Nampa, Idaho.
• Ed Harness, Dairy Vetrinary Management in Jerome, Idaho.
• Bradley Mills, DVM, Vetrinary Operations, Pfizer Animal Health in North Carolina

Q: How do you develop mastitis management programs with your customers?


Millard: First, I discuss the producer’s goals. Some dairy operations are content with a somatic cell count (SCC) under 500,000 cells/mL. Others aren’t happy if their SCC is more than 100,000.


It all depends on the goals of the individual and what he or she is seeking from the bulk tank SCC and individual treatment success rates. From there, I can sit down and look at culture and treatment records and write a protocol that best fits the dairy operation’s needs.


Harness: I try to be a very integral part of my customers’ mastitis control program. I look at everything they do, including record-keeping, treatment protocols, measurement of success and training.

Reliable record-keeping is extraordinarily important and records provide valuable information for decision-making.

Mills: The key to a successful program is working with the herd veterinarian to develop protocols.



As a veterinarian, I can look at culture records to understand mastitis pathogens common on the dairy operation and help best match the antibiotic treatment to the bacteria.

I can also take into account my professional experiences with treatment success from other dairies.

Q. What factors do you consider when developing a treatment protocol?

Millard: Culture records are the #1 consideration. Our practice has a lab that processes individual cow samples each day.

Along with culture results, I provide my customers with a list of cows that need to be treated, which receive the same extended mastitis therapy protocol. The culturing program allows us to base treatment on individual cow records and be smart about antibiotic use.

Harness: Many factors go into the decision of what kind of treatment to utilize. We need to look at historical events and what we learn from those experiences. Records play an important role. You need records to know if protocols are working – whether you are a 50-cow dairy or a 5,000-cow dairy.

Mills: Matching the bug to the drug is critical. Other factors play a role, including grading infections by severity, past treatment history of the individual cow and analyzing records to determine duration of therapy.

For example, a cow infected with Staphylococcus aureus should be aggressively treated with a longer, eight-day extended therapy.

Q. What treatment length do you recommend? When is extended therapy appropriate?

Millard: If a dairy producer wants to treat mastitis with a cure as the end goal, extended therapy is the only protocol of choice. I recommend an extended therapy protocol for every treatable case of mastitis. The prescription I give is a seven-day treatment regimen with a mastitis tube labeled for extended therapy.

Harness: At a minimum, I prescribe a two-day to five-day mastitis treatment for all cases or cases without culture records to consult. Often, I recommend a longer duration of therapy – eight days of treatment – for contagious pathogens, in order to ensure the infection is eliminated so it isn’t passed to herdmates.

Mills: In general, I recommend at least a four-day to five-day mastitis treatment for every case of mastitis. We want to treat the infection early and aggressively, and maintain therapy at a concentration level above the minimum inhibitory concentration (MIC) for an extended duration.

This will kill the bacteria and help achieve a complete cure. A good rule of thumb is to treat two days past a clinical cure, or two days after the milk appears normal.

Q. What are the benefits of extended therapy?

Millard: There are several benefits of extended therapy that I communicate to my customers. By using an extended therapy protocol, producers can experience fewer re-treats, reduce the loss of milk production in the lactation, have fewer culling costs associated with treated cows and achieve better treatment success.

My customers use fewer mastitis tubes because cows are cured the first time and aren’t returning to the hospital pen for re-treatment – saving on both product and labor costs.

Harness: In the current economic climate, there is a paradigm shift in the thought process. With milk quality bonuses of greater importance, our producers need to think about finding a bacteriological cure, not just treating the clinical symptoms, to reduce chance of relapse. Extended therapy is the only tool for prevention of extended illness.

Mills: Extended therapy protocols provide a better chance for a complete cure. Successful treatment has many benefits – less chance of relapse, lowered SCC (sometimes by as much as three to four linear scores), higher productivity of the treated cow in that lactation, less chance of scar tissue in the udder or of other long-term health issues and a decreased chance of contagious pathogens passing to herdmates.

Research in chronically infected cows shows a two-day treatment with a cephalosporin approved for extended therapy reaches a 40 percent cure rate, but the same product given for an eight-day duration can reach a cure rate of 66 percent.

Q. Does the entire treatment protocol need to be followed?

Millard: It is extremely important to follow the full treatment protocol. I work with my customers to conduct employee training to ensure all milkers and hospital pen workers understand the treatment protocols and follow them to the end. The protocols are also laminated, in English and Spanish, and placed in the main hall or office for the workers to reference.

Harness: There are two types of protocols: Protocols that are followed and protocols that aren’t followed. Employee buy-in at all levels of the dairy operation is essential to implementation success.

Training must not only be on the protocols but the reasoning behind them. If a milker makes a change on day three of a three-day treatment protocol, the results we see aren’t valid and the producer can’t accurately measure the success of his treatment decision.

Mills: Yes. When setting up an extended therapy protocol, it is imperative the entire treatment protocol is completed to fully knock out the infection. Training of employees is important to make sure they understand what they are doing. Cleanliness and proper treatment administration, as well as following milk and meat withdrawal times, are all vital parts of protocol adherence.

Q. Why is it important for veterinarians to be involved in mastitis treatment decisions?

Millard: Veterinarians can help their customers utilize records to develop protocols based on data and science. Those records also provide a powerful tool for measurement of mastitis control programs.

Harness: I believe that for any mastitis management program to be successful, it is essential the vet is involved in decisions up front to help drive decisions on animal health management and protocol development.

Mills: In a time of increased scrutiny on antibiotic use and on-label antibiotic treatment, written protocols and prescriptions from a herd veterinarian are mandatory. Dairy producers need to work with their veterinarian to ensure they are utilizing on-label treatments and have written protocols completed and available at the dairy operation. PD


Garth Millard, DVM
Vet Logic Inc., Nampa, Idaho
• Dairy-exclusive practice serving 33,000 dairy cattle. Provides producers with sensible and effective mastitis treatment advice.


Ed Harness, DVM
Dairy Veterinary Management, Jerome, Idaho
• Serves approximately 20,000 head of dairy cattle and calf ranches representing nearly 40,000 head. Specializes in protocol development and management.


Bradley Mills, DVM
Veterinary Operations, Pfizer Animal Health
• Based in North Carolina and provides consultation to dairy producers across the United States on comprehensive milk quality and other animal health management programs.