ated, choose a cost-effective agent which provides appropriate antimicrobial coverage for the diagnosis that is suspected, and prescribe the optimal dose and duration for the antimicrobial which maximizes clinical therapeutic effect while minimizing both drug-related toxicity and the development of antimicrobial resistance. More simply, we still have the same rules . . . it must be safe for the animal, it must be effective in treating the disease, it must be cost- effective, no antibiotic residues in marketed product, and it should not result in antibiotic resistant bacteria.
These principles are broad and suggest a couple of places that you can start. First, establish what antimicrobials are used on your farm and where they are used. The obvious first place to look is the medicine storage for the lactating and dry cows, but don’t forget to look at what might be used for young stock and calves.
While most antibiotics are going to be administered by injection or pill, some also can be administered in feeds and water. Check with your nutritionist and feed supplier about ALL the ingredients in the feeds you purchase, and review the ingredients with your nutritionist and veterinarian. In particular, milk replacers and feeds for yearlings often have antibiotics.
Not all the antibiotics that we use on the farm carry the same weight for creating bacterial resistance. The main products that do not concern public health are the ionophores (monensin also known as Rumensin and lasalocid also known as Bovatec) and the coccidiostats (decoquinate also known as Decoxx). It’s not that imprudent use of these antibiotics won’t create resistance, it’s that any resistance that might occur does not have implications for the treatment of disease in people. Residues still are a consideration, so use these products as labeled.
Review all the antibiotics you have on hand with your veterinarian, and properly dispose of any that are outdated, no longer used, or not indicated for the diseases that you are treating currently. As mentioned in a previous article (August 25, 2010, page 551) in this series, antibiotic resistance is not an unusual event and is a consequence of exposing bacteria to antibiotics. In the end, nearly all the antibiotics that are in our medicine toolbox are important and critical for animal and human health and must be used carefully, that is, judiciously.
First, do all things preventive. Having to treat a cow or calf is expensive. It requires extraordinary efforts on the part of yourself and your employees because it is not part of the daily routines. For your calves, use effective colostrum management and feeding programs, feed for growth, and keep feeding and housing areas clean.
For your cows, routine prevention includes an effective feeding program, a well-designed close-up or transition cow program, an effective udder health program, and keeping housing areas clean.
Think before you treat
Remember that antibiotics are not the first line of treatment. There are many conditions that do not require antibiotic therapy or are not bacterial. Calf scours may be effectively treated with fluids. Cows with high body temperatures initially may be effectively treated with aspirin or other nonsteroidal drugs that might control fever. Cows lame due to laminitis do not need to be treated for an infection.
Here again, your employees are the key to making this work. Providing them with high-quality training and consistently monitoring the effectiveness of treatment protocols and their implementation will result in judicious use of antibiotics. Work with your veterinarian to develop good approaches to correctly diagnose, treat, and monitor success or failure of a treatment protocol.
When you use an antibiotic, use it only when indicated, choose a cost-effective agent which provides appropriate antimicrobial coverage for the diagnosis that is suspected, and choose the optimal dose and duration that maximize clinical therapeutic effect while minimizing both drug-related toxicity and the development of antimicrobial resistance. Many of our d