Successful Treatment of Gram-Negative Mastitis
US - Research from Cornell University, recently published in the Journal of Dairy Science,1 shows an 89 per cent cure rate of mild or moderate Escherichia coli mastitis infections — characterized by the cow not being sick or off feed but with visible signs of mastitis — when treated with extended intramammary antibiotic therapy.Conducted at five large dairy herds of 500 or more cows in New York, the trial uniquely looked at mild and moderate cases of Gram-negative mastitis and evaluated the efficacy of treating for five consecutive days with SPECTRAMAST® LC (ceftiofur hydrochloride) Sterile Suspension. The results showed that treated cows had significantly higher cure rates than untreated cows.
“Until now, no research has so vividly demonstrated treatment success of mastitis infections caused by Gram-negative bacteria like E. coli,” says Roger Saltman, DVM, MBA, Group Director, Pfizer Animal Health Cattle Technical Services.
“Our team set out to determine how well such infections would respond to extended antibiotic therapy; and we found that, in the majority of cases, they responded very well.”
Dispelling the myth of a self-cure
The results support a new way of thinking — that antibiotic treatment of Gram-negative mastitis can be successful. Specific revelations from the research include:
- For clinical mastitis caused by E. coli, 89 per cent of the cows treated with SPECTRAMAST LC showed bacteriological, or complete, cures, compared with 53 per cent of untreated control cows.
- Cows that were completely cured gave 8.8 more pounds of milk at the second test day when compared with cows that were not cured.
- Herd survival also was significantly higher in completely cured animals versus animals that were not cured.
“These results dispel the belief that Gram-negative bacteria do not respond to intramammary antibiotic therapy or that these infections will self-cure,” Mr Saltman says.
“For those already putting an extended duration of therapy protocol into practice for Gram-negative infections, the results have always been apparent. Now, however, research clearly supports such treatment decisions.”
Extended therapy makes a difference
Coliform mastitis can cause adverse impacts on dairy operations. Gram-negative bacteria, like E. coli, cause 40 per cent of all clinical mastitis cases. Supported by this research, dairy producers can confidently fight Gram-negative infections using extended duration of therapy with SPECTRAMAST LC.
One of only two FDA-approved intramammary mastitis treatments labeled for extended duration of therapy (two to eight consecutive days of treatment), SPECTRAMAST LC is efficacious against E. coli and other environmental pathogens, including coagulase-negative staphylococci and Streptococcus dysgalactiae.
Study background and details
In this randomized study, researchers evaluated both clinical and complete cures, with bacterial strain-typing performed to classify infections as “new,” “persistent” or “cure” across the course of treatment and recovery. After completion of the treatment and at equivalent time points for untreated control cows, two follow-up milk samples were cultured and strain-typed after the last treatment.
Important Safety Information: Inappropriate dosage or treatment intervals for SPECTRAMAST LC or failure to adhere to proper milk discard period will result in violative milk residues. SPECTRAMAST LC requires a 72-hour milk discard period and a two-day pre-slaughter withdrawal period following the last treatment. As with all drugs, SPECTRAMAST LC should not be used in animals found to be hypersensitive to the product.
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