Targeted mastitis therapy for dairy cows is a two-step approach: first identifying the mastitis-causing pathogen through culturing and then making a thoughtful treatment decision based on the results, according to Boehringer Ingelheim.
“When we culture mastitis, cases come in three flavors, so to speak: Gram positive, Gram negative and no growth,” Dr. Stephen Foulke with Boehringer Ingelheim said, noting that the focus should be on the first one. “We now know that Gram-negative and no-growth mastitis typically does not require treatment,” he added. “We could potentially cut up to 60% of treatment costs by only focusing on Gram-positive pathogens.”
“Targeting and treating Gram-positive mastitis cases can save dairy producers money on antibiotics and discarded milk as well as reduce hospital pen density,” said Dr. Daryl Nydam, a professor at the Cornell University College of Veterinary Medicine and faculty director at the Cornell Atkinson Center for Sustainability. “It also demonstrates the dairy industry’s commitment to thoughtful antibiotic use.”
Nydam outlined the two steps in a targeted approach to mastitis treatment:
1. Identify the pathogen. For mild to moderate mastitis, culturing helps identify the right animals to treat.
“In broad brush strokes, when you culture, the results are generally equally distributed as one-third no growth, one-third Gram negative and one-third Gram positive,” Nydam explained.
- No growth -- A no-growth case means that the cow has cleared the infection on her own and does not need antibiotic treatment. “Occasionally, it might be due to a different pathogen like mycoplasma that doesn’t grow under standard conditions or an intermittently shed bacteria like Staphylococcus aureus,” Nydam said.
- Gram negative -- “A Gram-negative infection stimulates an acute immune response that can cause inflammation and more systemic signs,” he added. However, most Gram-negative mastitis cases, including those caused by Escherichia coli, will self-cure, and antibiotic treatment will not alter the outcome. Not only that, but most antibiotics have limited efficacy against this pathogen.
- Gram positive -- Gram-positive mastitis cases do require antibiotic treatment and can become chronic if left untreated. Often, Gram-positive infections stimulate a less-acute immune response that results in prolonged inflammation and localized signs, Nydam said.
2. Make a thoughtful treatment decision. “When looking for an antibiotic, find a product that is effective against Gram-positive bacteria such as staphylococci and streptococci,” Foulke advised. “Ideally, the tube has a tip that allows for partial insertion, since long tips can actually drag bacteria up into the teat. Before using any kind of treatment, try to be diligent about properly disinfecting the teat ends with an alcohol pad. We also want a short-duration treatment (one to three days) to get cows back in the tank as soon as possible.”
“A treatment program should be designed in consultation with a herd veterinarian,” Nydam said. “For any mastitis control program to work, it is important to focus on having healthy, immunologically robust cows that are housed in clean, dry and comfortable environments. We also want to ensure proper milking procedures are in place, which includes cleaning and drying teats before milking, as well as properly maintaining milking equipment. Keeping animals healthy will be far better for the cows, the farmers and the public than any treatment plan.”