By Mike Smith
Establish a treatment routine for BRD
Diagnosing BRD is easy, says Mike Apley, Kansas State University microbiologist—as long as nobody’s checking your accuracy, that is.
That inability to reliably detect the beef industry’s most common and most costly disease makes cost-effective treatment an ongoing gamble. Case in point, according to Apley, one of the world’s leading authorities on medical treatments for the disease: Response to treatment can often be “too good,” if an apparently high response on first treatment and low death loss is actually only hiding the reality that healthy calves are being pulled and needlessly doctored. That reality illustrates the complex balancing act of BRD management: It’s not pretty to watch, but sometimes it’s better to let a single calf die than to over-treat a whole group.
What does successful BRD treatment look like? University of California, Davis veterinarian Terry Lehenbauer says it starts with good record-keeping combined with a realistic, critical, measurable analysis of treatment outcomes. From there, everybody in the outfit needs to be in close contact to make sure everyone knows and follows protocols and everyone’s constantly on the lookout for “procedural drift.” After that, it gets even tougher.
Successful BRD treatment includes accurate recordkeeping and a realistic, critical, measurable analysis of treatment outcomes.
The treatment decision hinges on individual treatment or metaphylaxis. USDA survey data show an injectable antibiotic is basically the universal treatment for BRD in feedlots—nearly every calf treated for BRD gets a shot. The real question then becomes a choice between an individual pull-and-treat or metaphylaxis—a mass medication during the incubation period of the disease to help protect an entire group when you suspect individuals are harboring a case.
Injectable antibiotics approved for such use include Micotil from Elanco, Zactran and Tetradure from Merial, Excede and Draxxin from Zoetis, Baytril from Bayer, and Nuflor and Zuprevo from Merck.
More than half of feedlots incorporated an injectable antimicrobial into the arrival processing for at least some cattle, USDA says, presumably to avert an outbreak of respiratory disease. More than one in five of all cattle entering the feedlot undergo metaphylaxis.
While the common choice is to jump to metaphylaxis, any treatment decision should be agonized over a little. Not only is it the kind of mass, preventive medication that seems to be the poster child for anti-feedlot activism, it also costs up to $15 per head, depending on the size of the dose and calf. However, there’s no denying its effectiveness: Numerous studies, both private and public, indicate you can expect about a 50% reduction in sickness rates and a 30% to 50% reduction in death loss.
“Even when the decision to apply metaphylaxis is postponed past receiving processing, pen-level treatment should still be on the table,” says Dan Goehl, a Canton, Mo., veterinarian. As the number of pulls pile up in a pen, applying pen-level metaphylaxis may be useful. Goehl suggests setting predetermined measurable points that trigger metaphylaxis—typically 20% to 25% of the pen pulled in a day or if 10% of the pen is pulled two days in a row.
At the end of the day, metaphylaxis decisions should be based on one driving question, says Dee Griffin, director of Nebraska’s Great Plains Veterinary Educational Center: What is the likelihood that this group of cattle will have a high rate of respiratory disease? Typically, that question is answered by risk-rating the group based on any number of factors, including:
- Weather and the level of heat and cold stress
- Environment and dust or mud prevalence
- Days since weaning
- Commingling cattle from multiple sources
- Purchase source
- Age and weight of the calf
- Time in transit, dehydration, exhaustion
- Recent castration or dehorning
- Value of the calf
- Availability of help and time to check pens
- Vaccination history
- Availability of (and willingness to use) management techniques other than metaphylaxis that could reduce a pending BRD outbreak to a manageable level.
All those factors should be compiled to determine a specific risk level for each pen of calves, either using your own model or one of the systemic scoring systems developed by researchers, which will guide the decision to apply metaphylaxis or elect to pull cattle that come up sick. Doing so has been shown to increase your odds your treatment will succeed.
Timing is also a consideration. Does metaphylaxis have to be applied right off the truck to work? Not necessarily. Research from Nebraska shows delaying metaphylaxis for six days produced nearly the same outcome as administering treatment immediately at receiving. Although the predictability likely varies based on the risk of cattle, it does suggest you may be able to wait on groups with the risk-rate on the bubble.
The other aspect of treatment timing, how long you should wait after metaphylaxis until you decide it’s time to start pulling sicks, is a discussion that should be had with an experienced veterinarian, based on your case history data. The prevalence of new-age injectable antibiotics that are both more effective for longer periods and more expensive has led to the phenomenon of the mandatory post-treatment interval. That is, a strict window following a treatment shot in which no further antibiotic will be allowed, regardless of how a calf looks. It’s one of those strategies that looks good on paper but is hard to stick to once it costs a few highly-visible dead calves—even if it saves overall treatment costs.
An example of in-the-heat-of-the-moment BRD medical decisions includes the still too-common practice of combining two or more antibiotics. It’s more expensive, no research supports any improvement in outcome, it adds stress and it increases unnecessary antibiotic use. To Kansas State’s Apley, it belongs in the same medical volume as the one advising you that which direction you throw a fresh gelding’s testicles affects his temperament.
Have a written BRD treatment protocol, based on close consultation with a veterinarian using your own case-history figures, and stick with it.
USDA survey data shows feeders are adding secondary treatments for BRD beyond antibiotics. About half of affected cattle will get a dose of vaccine, presumably on the belief it will help them later immunologically should they survive initial treatment. About a third get a vitamin C injection, and about one in five get a nonsteroidal anti-inflammatory drug.
Reviews of the published research show there’s not a lot of hard data to back up use of secondary treatments for the benefit of reducing economic impact (as opposed to improving animal comfort and welfare).
You can argue that discrepancy between the research journals and the real world reflects either the value of experience or the belief cheap insurance is better than no insurance, but it also demonstrates the age-old truism that the best BRD defense is one that begins cow-side.
“Prevention of BRD should ideally begin with sound husbandry management at the ranch, accompanied by pre-arrival vaccination and weaning programs,” says Tom Edwards, feedlot veterinary consultant, Midwest Feedlot Services, Kearney, Neb.
Practice may show that waiting until the feedlot gate to start building calf immunity against BRD may work, but it also greatly exaggerates the already risky process of keeping the immune system ahead of the disease, he says.
Internal data from Cactus Feeders, which feeds more than a million calves a year, show that despite better treatments, death loss from BRD has continued to rise slowly but steadily since 2001.