Producers strive to provide a safe and high-quality food supply and, when necessary, appropriate use of anti-infectives is a vital part of assuring animal health and well-being. When dealing with costly diseases like bovine respiratory disease (BRD), it is important that producers understand the healing process and the science behind the medications they’re using as part of that process.
- killing or slowing the infecting agent
- cleaning up infected tissue
- repairing or replacing damaged tissue
- returning tissue to its healthy, natural function
“The first of those four steps is the only one that the anti-infective can influence,” Brumbaugh says. “The anti-infective works along with the animal’s own defense system in this step to start the process of healing. While it is very important, it is not the only step in healing. The rest of healing has to do with natural processes in the animal.”
Signs say each animal is different
There can be differences among animals in their ability and time it takes to heal. And, clinical signs can improve even though true healing is not complete. That is why several days to weeks of effective treatment are important. The anti-infective used to treat BRD can help allow the animal’s biological processes of healing to proceed if it remains in the lungs long enough.
The severity of clinical signs of BRD is partly due to the infection and partly due to the animal’s own response to the infection. Clinical signs used to identify an animal with BRD should resolve during recovery. “It is possible to measure clinically the ability of a medication to help the animal recover – that’s called efficacy,” explains Brumbaugh. “However, in sick animals, the complexities of healing prohibit measuring how ‘fast’ the anti-infective contributes to the first step of healing.”
Speed of response is a misnomer
According to Brumbaugh, “speed of response” is probably more indicative of how early in the disease process the animal is treated and the severity of the condition, not how fast the medication does its part after administration.
“When we think about ourselves, if we are sick and take medicine, we don’t immediately jump out of bed and go fix ourselves a big steak dinner and get back to work like nothing is wrong with us,” he explains. “The effectiveness of an anti-infective should be considered in the context of the net effect of all of the factors of healing working together. The medication and the animal must each do their respective parts.”