The use of antibiotics in animal agriculture is under more scrutiny than ever. Obviously, some control is good; we have one of the safest food supplies in the world. However, certain regulations may seem cumbersome and lack scientific support.
The recent proposed ban on extra-label use of cephalosporins highlights the need to take a step back and access the need for antibiotic use on a case-by-case basis. There is debate as to the role antibiotic use on dairies has in creating resistant bacteria, but the reality is tighter control of drug use is in our future. Prudent antibiotic use goes a long way in retaining the tools we need.
Prevention is always your first line of therapy. Do not look for a cure in a bottle. Through proper herd management, good facilities, adequate nutrition and a sound vaccination program, you can prevent many of the common diseases that require antibiotic use.
When faced with a sick cow or calf, first ask if antibiotic treatment is necessary.
Have you performed a physical examination and determined what the disease is? A lame cow with a foot wart is not in need of systemic antibiotic therapy. Many producers successfully treat viral infections with non-steroidal anti-inflammatory drugs and supportive therapy. Likewise, many cases of calf scours respond as well to supportive care without antibiotics.
When it becomes necessary to treat an animal, follow protocols that have been developed with your herd veterinarian.
Choose antibiotics based on the condition being treated. The type of bacteria and site of infection helps determine which specific antibiotic will have the greatest likelihood of cure. Bacterial cultures also help determine the type of antibiotic and duration of treatment, especially for mastitis.
Once treatment begins, it is important to administer the correct dose for a given duration. You cannot expect to give a 1,300-pound, first-calf heifer the same dose as a 1,600-pound cow. If the drug is labeled for twice-daily injection, then don’t double the dose once per day. This diminishes the response and may cause resistance. Likewise, you cannot treat for a few days and expect a successful outcome. In most cases, systemic antibiotic treatment must be given for a minimum of four days, and many cases require a longer duration.
When dealing with multiple affected animals or herd outbreaks, you and your veterinarian must decide which individuals to treat. It may be beneficial to treat some animals metaphylacticly (preventatively), but you should also focus on treating the fewest cases necessary. If treating large groups of animals is a common occurrence on your dairy, then husbandry needs to be examined.
Once you have started antibiotic treatment, don’t forget to record the drug, dose, duration and milk/slaughter withholds (and of course, identify the cow). Certain dairy-herd software systems make this a simple task and also track the milk- and slaughter-withhold dates. It is also useful to record treatment outcomes. These data can assist in future protocol revisions.
Communicate with your veterinarian
Finally, continue to utilize your veterinarian for treatment recommendations. There are new drugs, new regulations and new data to help make this process more science-based and less of a guess.
A valid veterinarian-client-patient relationship is required for extra-label use of drugs. Avoid the use of unapproved drugs or the use of two or more antibiotics simultaneously, unless directed by a veterinarian.
Although we are fortunate to live in a country where producers can use antibiotics on their own without the direct involvement of the veterinarian, this freedom has been questioned by certain groups attempting to significantly reduce the use of antibiotics.
Follow these guidelines to use antibiotics prudently so we can continue to protect the integrity of our food supply, as well as ensure animal health.
Mark J. Thomas is a veterinarian and owner of Countryside Veterinary Clinic, LLP in