BRD: Know Your Bacteria to Protect Against the No. 1 Cause of Mortality In Weaned Calves

Boehringer Ingelheim

Bovine respiratory disease (BRD), also known as shipping fever or pneumonia, is one of the most devastating and prevalent diseases in calves. In fact, it’s the No. 1 cause of mortality in weaned animals.1

“Morbidity and mortality associated with BRD can be detrimental in many ways,” said Whitney Knauer, VMD, Ph.D., assistant professor, University of Minnesota. “Young animals diagnosed with BRD have been associated with a higher risk of death, reduced growth rates, an increased age at first calving, and lower milk production during the first and second lactations.”2,3

So, what are some ways producers can avoid disease and efficiently raise high-performing animals? Dr. Knauer explains that it’s valuable for producers to know the type(s) of bacteria causing the pneumonia outbreak because it can help guide treatment and prevention strategies.

The four BRD-causing bacteria are Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Mycoplasma bovis.

  • Mannheimia haemolytica is the most common bacteria found in the lungs of calves with BRD. While other bacteria require more than one agent to break down the calves’ respiratory defense mechanisms, M. haemolytica can act alone.4



  • Pasteurella multocida is a normal inhabitant of the upper airway of cattle and is also one of the most common bacteria found in the lungs of calves with BRD.
  • Histophilus somni may be involved in cases of pneumonia, and can cause severe damage to the heart muscles and nervous system.4 Stress can activate H. somni residing in the upper airway, resulting in an invasion of the bacteria into the lower airway.
  • Mycoplasma bovis has been discovered more often in the past few years. It is usually found in combination with other bacteria, and not only causes severe pneumonia in both calves and cows, but also swollen, painful joints.5 Dr. Knauer explained that some spread of this bacteria can be attributed to feeding non-pasteurized milk in infected herds, and even in herds that pasteurize milk but do not monitor the effectiveness of the pasteurization.

“It’s important to work with your veterinarian to diagnose types of bacteria early in the disease process to choose the most appropriate treatment,” explained Dr. Knauer. “Waiting too long, treating with multiple classes of antibiotics, and inappropriate dosing can all contribute to treatment failure and mortality, as well as increase the risk of antibiotic resistance development.”




Curt Vlietstra, DVM, Boehringer Ingelheim, echoes Dr. Knauer. “They’re quite the mouthful but identifying these types of bacteria can help producers choose a product that provides the correct coverage,” he said. “If we don’t know what type(s) of bacteria we’re dealing with, we have to make assumptions, and may or may not be addressing the cause of the problem. I recommend using an antibiotic labeled to cover all BRD-causing bacteria to treat calves quickly and minimize the negative impact of BRD.”

Boehringer Ingelheim’s Animal Health Business has a significant presence in the United States with more than 3,000 employees in places that include Georgia, Missouri, Iowa, Minnesota, New Jersey and Puerto Rico. To learn more, visit, ©2020 Boehringer Ingelheim Animal Health USA Inc., Duluth, GA. All Rights Reserved. US-BOV-0255-2020


1  USDA APHIS, Veterinary Services. NAHMS. Heifer calf health and management practices on U.S. dairy operations, 2007. January 2010. Available at: CalfHealth.pdf. Accessed April 4, 2019.

2  Correa MT, Curtis CR, Erb HN and White ME. Effect of calfhood morbidity on age at first calving in New York Holstein herds. Prev Vet Med 1988;6(4):253–262.

3  Heinrichs AJ and Heinrichs BS. A prospective study of calf factors affecting first-lactation and lifetime milk production and age of cows when removed from the herd. J Dairy Sci 2011;94(1):336–341. Available at: https://www. Accessed April 18, 2019.

4  Kasimanickam R. Bovine respiratory disease (shipping fever) in cattle. Washington State University Extension and WSU College of Veterinary Medicine. 2010. Available at: BovineRespiratoryDisease_Aug20103.pdf. Accessed April 4, 2019.

5  Fulton RW, Ridpath JF, Saliki JT, et al. Bovine viral diarrhea virus (BVDV) 1b: predominant BVDV subtype in calves with respiratory disease. Can J Vet Res 2002;66(3):181–190.


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