Increasing Cases of Toxic Mastitis
by Carrie Bargren, DVM
With the hotter, more humid weather now upon us, we have seen an increasing number of down, toxic mastitis cases, which may continue in frequency for the next few weeks. Toxic mastitis is a more severe form of mastitis that becomes a systemic infection with a death/cull rate of 30-40%.
It is most commonly caused by bacteria found in manure, such as E. coli and other coliforms, that enter the mammary tissue through the teat canal. They begin rapidly dividing, reaching peak concentrations in only a few hours. The immune system responds rapidly and most infections are cleared without treatment with few or mild clinical signs: watery or yellow milk; a hard, swollen or painful quarter. The unlucky cows that are unable to clear the local infection develop a systemic infection where the whole body is affected and they will develop a fever, go off-feed and eventually go down. When a cow has these symptoms, she should be seen quickly so treatment can be started.
The key to treatment is hydration and supportive care. When the bacteria are killed by the immune system, they release a toxin that can cause fatal damage to the kidneys. Giving a cow IV fluids and pumping her with water and Appetite Drench keeps her hydrated and flushes the kidneys to minimize damage. In addition, she needs an anti-inflammatory (like Banamine) to reduce her fever and reduce the inflammation caused by the toxin.
An antibiotic, like oxytetracycline, is needed systemically for a few days to fight the infection in the body, but is also necessary in the mammary gland itself as systemic antibiotics have a hard time getting into the mammary tissue. Spectramast is the only intramammary treatment that is effective against E.coli and other coliforms and should be given for up to five days. The cow should also have some calcium as it is used in fighting the infection and could be contributing to her not being able to get up if she is already down. Depending on the severity of her infection and how soon treatment was started, the cow may need to be given additional fluids in the following days. Before starting treatment, a milk sample can be taken for an in-house culture and sensitivity to ensure the correct antibiotic is being used.
Between the lost milk, treatment and labor, the cost of a case of toxic mastitis can become fairly expensive, so prevention is often the best option. Since the bacteria are picked up from the environment, good milking hygiene is important; especially the pre-dip which provides control against environmental bacteria. The post-dip controls contagious bacteria that are passed between cows on the milking machine itself. Whether it’s a pre- or post-dip, check your aim and make sure the entire teat gets covered! Also, make sure the teat is completely dry before putting on the milking machine. Having clean, dry bedding is ideal to reduce the bacteria growing in it, but keeping the cows standing immediately after milking gives the teat sphincter time to close before she lays down.
There are a few vaccines available against E. coli which will reduce the severity of clinical signs, but will not prevent infection J-Vac, by Merial, is labeled to reduce clinical signs of E. coli mastitis as well as the effects of endotoxemia caused by E. coli and Salmonella typhimurium. Another product, Enviracor J-5 by Zoetis, is labeled to reduce the clinical signs of E. coli mastitis. The vaccination schedule for both products is the same: vaccinate at 7 and 8 months pregnant followed by a third dose starting at 1-2 weeks post-calving but can be given as late as 6 weeks fresh/prebreeding. The dosing is 2mL of J-Vac in the muscle or under the skin and 5mL of J-5 under the skin. An option for herds that consistently struggle with toxic mastitis is to vaccinate the herd quarterly on a calendar basis.
The costs are about $2.40 per dose of J-Vac and $1.84 per dose of J-5. At $7.20 (J-Vac) and $5.52 (J-5) per cow per lactation respectively, 35 cows can be vaccinated for the same cost of the initial treatment of one cow with toxic mastitis, not to mention follow-up treatments and the loss in milk production. If you have any questions, we’d be happy to discuss them with you by phone or the next time we are at your farm.
Low Cost Spay/Neuter
Do you have just the right number of barn cats and aren’t looking for more? Having these cats spayed or neutered will help control the wild feline population. It can actually help cats live longer, happier lives by eliminating the risk of cancer in the reproductive organs as well as reduce aggression and their tendency to roam.
The Dane County Friends of Ferals offers monthly spayathons where cats are brought into Madison from nearby counties to be spayed or neutered. The event is free with a recommended donation of $25 per cat and provides excellent experience for vet students and vet tech students under the supervision of licensed veterinarians and technicians. If you’re interested, email firstname.lastname@example.org to learn more and sign up.
The Iowa County Humane Society is now offering a low income spay/neuter program for household cats and dogs. Once your application is approved, ICHS will provide a voucher to discount the cost of the procedure at participating veterinary clinics. Find the application and more information at www.ichs.net and scroll down.
The Spay Me! Clinic in Madison also specializes in low cost spay/neuter services. For more information, their website is www.spayme.com.
Newborn of the Month:
It is our pleasure to announce the arrival of the newest member of the River Valley Vet team: Graham Allan Kruse was born on July 29th at 5:35am, weighing 9lbs 15oz and 20inches. Dr. Ashley and Graham are doing well as is the rest of the family!