Bovine Respiratory Disease in Cattles

Bovine Respiratory Disease (BRD) is the most common and costly disease affecting the North American beef cattle industry. In the broadest sense, BRD refers to any disease of the upper or lower respiratory tracts. BRD is commonly associated with infections of the lungs causing pneumonia in calves that have recently been weaned or recently arrived at the feedlot (which is why it is often referred to as shipping fever). BRD is most prevalent within the first weeks of arrival to the feedlot, but it can occur later in the feeding period and is also seen in calves on pasture. 

• Bovine Respiratory Disease (BRD) is the most common and costly disease affecting the North American beef cattle industry

• It is often referred to as shipping fever

• BRD is most prevalent within the first weeks of arrival to the feedlot, but it can occur later in the feeding period and is also seen in calves on pasture

• Classical clinical signs of bacterial BRD include:

• fever of over 40°C (>104°F)

• difficulty breathing

• nasal discharge

• varying degrees of depression

• diminished or no appetite (‘off-feed’)

• rapid, shallow breathing

• coughing

• Risk factors

• Environmental factors such as transport, adverse weather, co-mingling, stressful events (ie. dehorning, castration, weaning, auction)

• Prevention

• Precondition calves before marketing

• After arrival at the feedlot, provide a vaccination and general good animal husbandry

• Treatment

• It is best to work with your veterinarian for the appropriate medication and dosage

• Common causes of treatment failure include;

• Pathology of the lesion too far advanced

• Wrong diagnosis

• Simultaneous disease process (e.g.: Overt IBR, Post calving metritis)

• Inadequate dosage

• Overuse or inappropriate use of Ancillary Pharmaceutics  
•  
• Causes: 

BRD is a complex multi-factorial disease, which means that a number of factors must interact to cause the disease. For example, researchers can recover the bacteria and viruses responsible for BRD from the nasal passages of healthy cattle. However, other factors such as the stress from transport, mixing, and weather are needed in order for BRD to develop. There are 3 main categories of factors associated with all diseases, and BRD in particular: 

• Host factors, which refers to the characteristics of an animal that make it more prone to the disease, such as: age, immune status, prior exposure to the pathogens, genetics, etc. environmental factors such as transport, commingling, temperature fluctuations, crowding, ventilation, auction-sourced, etc.  
  Infectious agents or pathogens that are necessary for causing the disease. These can broadly be categorized as viruses, bacteria and parasites: Viruses, including: bovine herpes virus (IBR); bovine parainfluenza virus (PI-3); bovine respiratory syncytial virus (BRSV); bovine viral diarrhea virus (BVD), and bovine coronavirus (BCV). 
  • Bacteria, including Mannheimia haemolytica, Pasteurella multocida, Histophilus somni and Mycoplasma spp. 
  • Parasites, including lungworm 

• BRD is a complex multi-factorial disease, which means that a number of factors must interact to cause the disease. For example, researchers can recover the bacteria and viruses responsible for BRD from the nasal passages of healthy cattle. However, other factors such as the stress from transport, mixing, and weather are needed in order for BRD to develop. There are 3 main categories of factors associated with all diseases, and BRD in particular