Mastitis is not just a somatic cell count issue anymore
Escherichia coli is different from the mastitis cases we used to see. It’s not simply a somatic cell count issue — it’s a cow health issue.
“Since I graduated from veterinary school almost 30 years ago, there have been big shifts in the types of mastitis found on farms,” stated Stephen Foulke, DVM, DABVP, Boehringer Ingelheim. “We used to mostly deal with contagious mastitis cases, which we’ve done a good job of managing. Now the mastitis we’re seeing more often are environmental cases, including Gram-negatives like E. coli.”
As environmental pressures such as herd size, stocking density and milk production continue to increase, we’re going to continue to be challenged with Gram-negative mastitis. “When cows come down with E. coli, they can get knocked back hard,” Dr. Foulke said. “They become sick enough that their milk production shuts down, and it can even be fatal. Animals that do recover never really make it back to the peak production they once were at.”
Preventing E. coli on a dairy operation is a twofold process, addressing the cow's environment and building up the cow's immunity.
Address cow’s environment
“E. coli and other types of Gram-negative mastitis strains are found virtually anywhere cows are housed, such as in bedding, the milking parlor and manure,” pointed out Dr. Foulke. “We have to keep their environment as clean, dry and comfortable as we can to prevent teat ends from getting exposed to manure.” This includes frequent scraping of alleys and holding pens, as well as keeping stalls, or wherever cows lie down, well-bedded and maintained.
“We also need to continue to follow good milking procedures,” advised Dr. Foulke. “That means making sure milking equipment functions properly, and teats are clean and dry before attaching milking equipment. You’ll want to use an effective teat dip immediately after milking and maintain good udder hygiene between milkings.”
Build up immunity
If faced with E. coli, cows need to have a robust immune response to fight off the infection. Building immunity involves a strong nutrition program that includes trace minerals and plenty of water, as well as vaccination.
Vaccination is critical in reducing the severity and incidence of E. coli.1 “Most E. coli infections are going to happen right around freshening, due to increased stress, so I recommend getting ahead of the problem by vaccinating all cows at dry off, then giving a booster vaccine four weeks later,” added Dr. Foulke. “The vaccine you choose should have a short meat withdrawal and provide protection against E. coli, endotoxemia caused by E. coli and Salmonella Typhimurium.”
If you think you’ve got an animal experiencing a case of E. coli, intramammary antibiotic treatment may not be necessary. “We know from research that not all mastitis cases have to be treated,” Dr. Foulke noted. “In some cases, the cow will cure herself.” That’s why, for mild or moderate mastitis, he recommends producers take a milk sample, culture it and wait for results before treating.
“Gram-negative mastitis grows very fast, so you can culture and know by the next day what kind of bacteria you have,” said Dr. Foulke. “For those infections that need treatment, such as Gram-positive organisms, knowing the bacteria involved can help you select antibiotics that will be most effective.” However, if cows are visibly sick, start treating immediately with fluids, anti-inflammatories and injectable antibiotics, then adjust treatment as needed based on the culture result.
“Dealing with E. coli starts with your veterinarian,” Dr. Foulke concluded. “He or she can help you create a management and prevention protocol best suited for your operation.”