“The research is clear — if we want to tackle respiratory disease, we need to focus on early diagnosis and effective treatment,”1,2 said Dan Cummings, DVM, Boehringer Ingelheim. “If we aren’t able to identify and treat sick calves right away, we’re going to face short- and long-term consequences. Initially, nursing calves infected with bovine respiratory disease (BRD) could weigh up to 36 pounds less at weaning than their healthy herd mates.3 Down the road, an infected replacement heifer is going to breed later in life, produce less milk and is more likely to be culled from the herd sooner.”
BRD, commonly known as pneumonia or shipping fever, is most often associated with stocker and feedlot operations, but it should also be on the radar for cow-calf producers. Almost 20% of cow-calf operations experience nursing-calf pneumonia, and it’s the leading cause of death for calves 3 weeks of age and older.4 To keep calves on the right track, consider the following diagnostic tools and treatment protocols.
“I consulted with a stocker operation in practice that routinely purchased high-risk bull calves from a sale barn,” Dr. Cummings recalled. “His employees were struggling to understand the diagnostic and treatment protocols that were in place. At the end of the day, calves weren’t being diagnosed accurately or consistently. Additionally, employees weren’t sure which calf was treated with which antibiotic due to improper record keeping. We decided to simplify the protocol and implement the D.A.R.T. assessment. It wound up being easier for employees to understand and use consistently from one day to the next. It also resulted in more accurate BRD diagnosis and improved treatment success.”
The D.A.R.T. assessment is a four-step approach:
- Depression: A sick calf will have droopy ears and hold its head lower than normal. The calf’s movement may be stiff, and its tail may be tucked slightly.
- Appetite: At feeding time, watch carefully for animals that are slow to come to eat or have a reduced appetite.
- Respiration: Look for abnormal patterns such as exaggerated, heavy breathing, flared nostrils and a soft, persistent cough.
- Temperature: This is the only objective measurement in the D.A.R.T system. “A normal temperature is going to be around 102 degrees Fahrenheit,” noted Dr. Cummings. “If the calf is running a temperature above 104 degrees, that calf may be eligible for treatment.”
Along with using a thermometer, a stethoscope is a relatively inexpensive tool that producers can use to evaluate the lungs and diagnose BRD sooner. “Lung ultrasounds are another great way to diagnose clinical or subclinical cases of BRD,” said Dr. Cummings. Subclinical cases of BRD are those that may not be detectable with visual observation alone. “The sooner we can diagnose animals infected with BRD, the less likely we are to see permanent lung damage and subsequent performance losses. Ask your veterinarian to come out and perform the ultrasounds, or make sure you’ve got the proper training from the veterinarian to do it on the farm.”
When looking at BRD treatment options, Dr. Cummings explains that some key considerations can lead to better treatment outcomes:
- Ensure your antibiotic provides coverage for the four bacterial pathogens that cause BRD: Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Mycoplasma bovis.
- The treatment should be proven to reach the lungs (site of infection) quickly, and be effective for an extended period of time. “I think it’s also important for producers to visually observe that the calf has responded to the antibiotic and is showing signs of improvement. We want the calf alert, getting back to the feed bunk and breathing normally,” said Dr. Cummings.
- Record keeping helps communicate the treatment status of an animal to anyone who might be working on the operation and ensure proper withdrawal times are followed. It’s also a way to measure treatment outcomes and identify chronically sick calves.
- Working closely with a veterinarian is critical to the success of any protocol to control BRD. They’re going to be able to evaluate records and help make informed treatment decisions or changes.
Metaphylaxis is the strategy of administering antibiotics to groups of animals to prevent disease. It’s a tool to explore when we know calves are going to experience stressful events (such as shipping and commingling) or significant disease challenges. “One of the goals with metaphylaxis is to treat subclinical cases of BRD that we may not be able to identify with the diagnostic protocols in place,” Dr. Cummings stated. “If we strategically and judiciously implement metaphylaxis, then we can treat individual BRD cases and reduce the spread of disease in that group of calves.”
No matter the protocols adopted, it’s important to regularly monitor your operation for procedural drift. “Procedural drift happens in many areas of agriculture, from milking routines on the dairy to cattle handling and processing,” asserted Dr. Cummings. “It can be easy to drift away from best practices to whatever feels comfortable when things get busy. We can prevent procedural drift by continually training employees, ensuring protocols are clearly posted and explaining the ‘why’ behind established protocols.”
Looking beyond diagnostics and treatment protocols
Good BRD management is more than thoughtful treatment or diagnostic tools. “When I discuss successful approaches in controlling BRD with producers, I think the lightbulb goes on for many when we understand that controlling BRD requires a multifaceted approach,” said Dr. Cummings. There are numerous factors that can put calves at risk for developing BRD, such as:
- Nutrition or hydration status. A solid nutrition program that includes adequate protein, energy, trace minerals and plenty of water will help an animal’s immune system work properly and fight disease.
- Parasite problems. If a calf has a heavy parasite burden, it will negatively impact the immune system and its ability to respond to foreign pathogens.
- Viral diseases can further suppress the immune system and increase the risk of BRD, namely bovine viral diarrhea virus (BVDV).5 When purchasing animals, there’s a chance that they are persistently infected (PI) with BVDV. “A PI animal will often appear normal and healthy, but they’re actually shedding the virus onto the rest of the group,” explained Dr. Cummings. “That’s why testing and removing these animals is an imperative biosecurity measure to control BVDV.”
- Not following the antibiotic label. “I often see antibiotics used improperly because the animal wasn’t weighed or the route of administration was incorrect,” said Dr. Cummings. “To improve treatment success, take time to read the label and talk with a veterinarian on best administration practices.”
Dr. Cummings concludes that when producers take on a multi-pronged approach to BRD management, that’s what’s going to help them achieve success in the long run.
1 White BJ, Renter DG. Bayesian estimation of the performance of using clinical observations and harvest lung lesions for diagnosing bovine respiratory disease in post-weaned beef calves. J Vet Diagn Invest 2009;21(4):446–453.
2 Timsit E, Dendukuri N, Schiller I, Buczinski S. Diagnostic accuracy of clinical illness for bovine respiratory disease (BRD) diagnosis in beef cattle placed in feedlots: a systematic literature review and hierarchical Bayesian latent-class meta-analysis. Prev Vet Med 2016;135:67–73.
3 Wittum TE, Perino LJ. Passive immune status at postpartum hour 24 and long-term health and performance of calves. Am J Vet Res 1995;56(9):1149–1154.
4 Woolums AR. Risk factors for BRD on cow-calf operations, in Proceedings. 48th Annu Conf AABP. 2015.
5 Booker CW, Abutarbush SM, Morley PS, et al. The effect of bovine viral diarrhea virus infections on health and performance of feedlot cattle. Can Vet J 2008;49(3):253–260.
©2020 Boehringer Ingelheim Animal Health USA Inc., Duluth, GA. All Rights Reserved.