Bovine Respiratory Disease, often referred to as BRD or "shipping fever," is a complex cattle disease that can be caused by a combination of many factors. BRD can affect the lower or upper respiratory tract in cattle, and has serious economic implications.
Despite numerous cattle vaccines and antibiotics on the market, BRD remains a deadly disease. In total, 16.2% of all cattle are treated for BRD, and it is the cause of 40% of cattle mortality (death) in the United States.1,2
Stressors such as shipping, processing and adverse weather trigger the release of cortisol throughout the body of the calf, cow or steer. This can in turn compromise the immune response, weakening the animal's defenses against viral and/or bacterial infection.
Viruses successfully invade the nose and lungs due to the animal's weakened immune barriers. Viruses can cause damage to the upper airways and cilia, and can replicate even in exposed, otherwise healthy cattle. Weaned calves are particularly susceptible to respiratory illness because of their underdeveloped immune systems.
The compromised respiratory system provides an ideal environment for housing harmful bacteria such as Mannheimia haemolytica, which has been associated with enzootic pneumonia in neonatal calves.4 Bacterial lung infections in cattle cause the most lung damage and death. Lung damage can occur very quickly, within hours, and is permanent.
Proper cattle management to minimize stress is key to helping prevent Bovine Respiratory Disease, although many stressors such as weather and necessary transport are unavoidable. Cattle vaccines and antibiotics can be administered to help prevent or treat viral or bacterial infection.
Early detection and treatment may improve an animal's response to treatment, helping to reduce BRD mortality. Restoring the health of a sick steer or cow can also result in improved feeding performance. Keep a lookout for the following clinical signs of Bovine Respiratory Disease:
If left untreated, BRD can lead to reduced performance and even death. Cattle that have been sick generally gain less, are less efficient, and grade lower. Spotting BRD symptoms and pulling cattle early can help prevent irrecoverable loss of profit.
1Feedlot 2011 Part IV: Health and health management on U.S. feedlots with a capacity of 1,000 or more head. (2013). USDA website. Available at: https://www.aphis.usda.gov/animal_health/nahms/feedlot/downloads/feedlot2011/Feed11_dr_PartIV.pdf. Accessed October 23, 2015.
2Hilton M (2014). BRD in 2014: Where have we been, where are we now, and where do we want to go? Presented at: BRD Symposium; July 30-July 31, 2014; Denver, CO.
3Maday J. (2014). The ongoing battle with BRD. Bovine Veterinarian. (September): 30-33.
4Rice JA, Carrasco-Medina L, Hodgins DC, et al. (2007). Mannheimia haemolytica and bovine respiratory disease. Anim Health Res Rev. 8(2):117-128.