Bovine Respiratory Disease (BRD) is a very broad term that is used to describe various types of pneumonia in cattle.
“The most common form of pneumonia presents as infection and inflammation in deepest parts of lungs that lie near the heart,” said Dr. Brian Vander Ley, DVM, assistant professor of food and animal medicine for the University of Missouri’s College of Veterinary Medicine. “If untreated, BRD rapidly causes the lung tissue to be filled with fluid, immune cells and scar tissue making affected lungs unable to be filled with air.”
According to Vander Ley, classic respiratory disease is a three part process. First, cattle undergo a stressful event. Examples include weaning, castration, dehorning, marketing, transport, feed changes and etc. In the second stage, stressed cattle encounter viruses that damage the upper respiratory tract. This damage allows bacteria that normally live in the nose and throat of a healthy calf to move down into the lungs. Bacterial migration is the third step that causes inflammation and often permanent scarring in the lungs.
According to Dr. Jeremy Powell, DVM, associate professor in the Department of Animal Science at the University of Arkansas, clinical signs of BRD include a body temperature of greater than 104° F, a poor appetite, general weakness/dullness, gaunt appearance, separation from the herd, snotty nose and coughing.
Antibiotic therapy is the indicated treatment for BRD. “Many effective antibiotics exist and producers should consult their veterinarian to assist them with selecting antibiotics for treatment of BRD,” Powell said. “Early detection and subsequent treatment of respiratory disease is essential. If treatment is delayed, this will only increase the number of potential deaths or chronically infected animals.”
“There are two critical components to BRD prevention,” Vander Ley said. “First and most importantly, producers should do everything possible to minimize stress on cattle. Gentle handling, low-stress weaning strategies and prudent marketing all help minimize stress on cattle. Second, cattle should be vaccinated against common respiratory pathogens.”
Secondly, Vander Ley insist that at a minimum, calves should receive a dose of modified live IBR/BVD1/BVD2/BRSV/PI3 vaccine prior to weaning. “Cows, replacement heifers and bulls should also be vaccinated annually with the same modified live vaccine,” Vander Ley said. “Producers can also elect to vaccinate against the bacteria involved in BRD.”
BRD vaccination is really important, but it can’t stand alone. “I tell my clients that vaccination is like building a wall against the invading viruses and bacteria,” Vander Ley said. “To keep the wall from being used, producers must work to prevent exposure through biosecurity. Some examples of biosecurity include stopping at a carwash and cleaning your trailer after bringing cattle to the sale barn, and wearing different clothes and shoes when you could encounter animals or their manure/urine/saliva/nasal discharges.”
Vander Ley added that any vaccination is probably better than no vaccination. “There is growing research evidence that supports the value of modified live vaccines over killed vaccines,” Vander Ley said. “In any case, vaccines are very fragile and must be handled carefully to make sure they work. Producers should get BQA (Beef Quality Assurance) certified and follow BQA procedures when vaccinating their animals.”
Vander Ley recommended that producers keep a good record of vaccinations and treatments, including animal identification and product information such as product name, lot number and dose.
At its root, BRD is a management disease. “Producers can manage both their way in to and out of BRD outbreaks,” Vander Ley said. “Good livestock husbandry along with proper vaccination go a long way in preventing BRD.”
Powell added, that preconditioning calves before they are marketed can minimize their risk of BRD infection. Studies have shown that preconditioned calves have much lower BRD illness rates than cattle that are not preconditioned.
Producers can get more information from their local veterinarian for the treatment and prevention of bovine respiratory disease.
