Equine & Livestock Product & Promotions Guide

8 Covetrus | 855.724.3461 | northamerica.covetrus.com What we often don't know, but could (and should) What we often don't know, but could (and should) Too often, treatment decisions are based on "knowable" unknowns or on assumptions that may or may not be true. Taking steps toward more thorough mastitis evaluation and better recordkeeping can provide useful information to guide treatment decisions. Below are examples of how in- depth investigations could turn "unknowns" into "knowns," thereby potentially improving mastitis treatment success. Identify the cause of mastitis before treatment. If milk culture results can be obtained within 24 hours, then treatment decisions can be pathogen-based. Remember, cases of mastitis that are culture negative or that are caused by Gram-negative organisms rarely benefit from IMM antimicrobial therapy. Therefore, not treating cases of mild mastitis with signs confined to the mammary gland that are culture negative or caused by Gram-negative organisms with an IMM antibiotic results in both treatment cost savings and decreased selection for resistant organisms. Although there are few differences in cure rates between IMM antibiotics when evaluated against all pathogens, producers may want to work with their veterinarian to select treatments based on spectrum of activity against specific Gram-positive pathogens. If milk culture results cannot be obtained in 24 hours, consider collecting and immediately freezing milk samples from a subset of clinical cases prior to treatment. Give these samples to your veterinarian for culturing. This provides useful insight into the prevalence of each of the mastitis- causing pathogens in your herd and serves to monitor for particularly troublesome pathogens like Staphylococcus aureus. In cases where treatment is initiated prior to or without the results of milk culture, the default treatment should be short- duration therapy with an antibiotic that has outstanding Gram- positive coverage. The default treatment should not be extended therapy without the benefit of a bacteriological diagnosis. Don't rely solely on past experience. The most common reason cited by producers for choice of a specific IMM treatment product is: "It worked before." This selection criterion may not always be accurate, particularly since most clinical cases spontaneously cure regardless of treatment. Keep in mind also that human memory is fallible, and that we tend to remember and place much greater weight on single, clinically severe cases we did not expect to cure but did, as well as clinically mild cases that we expected to cure but did not. We may come to a different conclusion regarding effectiveness of a given treatment after objective analysis of actual treatment results. Nearly all farms could benefit from keeping more complete treatment records and carefully evaluating those records to determine product efficacy. Accurately measure culling due to mastitis. On many farms, the true "reason for culling" is difficult to determine from the records. Better recordkeeping systems could help evaluate failures to cure that lead to culling, potentially influencing future treatment decisions.

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