A recent study shows that antibiotics can be effective in treating coliform mastitis.

This refutes the long-held notion that antibiotics aren’t effective in treating coliform mastitis, which has people saying it’s now time for a paradigm shift.

“For me, this study shows that we always need to keep an open mind to how disease states change and how therapies can change,” says Roger Saltman, veterinarian and group director of Cattle Technical Services at Pfizer Animal Health.

Saltman acknowledges, “Even old dogs can learn new tricks.”

The study, published in the December 2011 Journal of Dairy Science by Saltman, along with practicing veterinarians in New York state and researchers from Cornell University, offers new hope for treating coliform mastitis.

Study details

Basically, the study showed a high cure rate for coliform mastitis with extended antibiotic treatment.

According to study co-author Ynte Schukken, veterinarian and director of Quality Milk Promotion Services at Cornell University, there was, in fact, a very large difference between treated animals and non-treated controls. The cure rate in treated animals was about 90 percent for E. coli and 75 percent for Klebsiella, compared to 25 percent for E. coli and 20 percent for Klebsiella in non-treated animals. (A small number of non-treated animals did experience a spontaneous cure in the absence of antibiotic treatment.)

The study shows that with certain antibiotics, you have a higher cure rate and a more predictable cure rate, Schukken says.

• “Cure,” in this case, refers to the absence of the organism that was present at the start of the case. Specifically, the offending organism does not show up in two milk samples taken after treatment.
• Cows in the treatment group received ceftiofur hydrochloride via intramammary infusion at 24-hour intervals for five days.
• These were mild to moderate cases of coliform mastitis with no signs of systemic illness.
• The study dispels the myth that Gram-negative bacteria like E. coli do not respond well to antibiotic therapy.

“Treatment of non-severe clinical Gram-negative mastitis with ceftiofur hydrochloride resulted in significant bacteriological improvement compared with non-treated control animals, particularly in animals infected with E. coli or Klebsiella,” the researchers said.

Saltman adds, “This study shows that the old paradigm of ‘don’t treat coliform infections’ was actually wrong because if you don’t treat them, they don’t get better — at least most of the time.”

Researchers have been looking for a long time to find management options for dairy farmers in the case of coliform mastitis, Schukken says, and now there is hope for getting a better handle on the problem.