Bovine Respiratory Disease: Causes, Symptoms & Preventions

Bovine respiratory disease, shipping fever pneumonia, or undifferentiated fever is a respiratory disease of cattle. BRD usually develops as a result of complex interactions between environmental factors, host factors, and pathogens. BRD is considered one of the most common and costly diseases which affects the cattle industry worldwide.

This disease can be much more difficult to detect and effectively treat in cows and calves on pasture compared to cattle confined to facilities. The impact of BRD oftentimes has a very significant impact on productivity, both short-term and long-term. Now, let us take a look at this complex disease, its causes, ways of prevention, and treatment.

Symptoms of BRD:

Symptoms of BRD in weaned calves, grass cattle, and feedlot calves include-

• Coughing

• Shallow and rapid breathing

• No or diminished appetite

• Constant nasal discharge

• Varying degrees of depression

Causes of BRD:

BRD is a complex disease that involves several interacting factors. Factors such as the stress from transportation, adverse weather conditions, and mixing unfamiliar cattle create the perfect environment for BRD to develop. In particular, BRD is associated with the following risk factors-

• Living conditions of the cattle- The living conditions of the cattle increase their risk of BRD. Cattle that are kept in poorly ventilated, dusty, and overcrowded conditions where they have to commingle with unfamiliar cattle and deal with temperature fluctuations are more likely to develop the disease.

• Pathogens- Pathogens, such as bacteria, viruses, and parasites, must be present in the cattle’s environment for the disease. Viruses, which include bovine parainfluenza virus, bovine viral diarrhea virus, bovine herpes virus, and bovine coronavirus are the causes of BRD infection and even predispose the animal to subsequent bacterial BRD infections. Parasites like lungworms and bacteria, including Mycoplasma bovis, Pasteurella multocida, and Manheimia haemolytica also cause BRD.

• Host factors- There are certain characteristics of an animal that make it more prone to the disease, such as nutritional status, immune status, prior exposure to pathogens, and genetics.

• Environmental risks- Heat stress, overcrowding, and high dust levels also contribute to the disease.

Prevention of BRD:

BRD can be prevented in bovines by following the aforementioned prevention strategies-

1. Adequate Nutrition- To prevent BRD, you must work alongside a veterinarian or nutritionist to ensure that the cattle are getting proper nutrients by including adequate mineral supplementation in their diet. It also involves modifying the diet of the cattle in whichever way possible.

2. Stress Reduction- Stress puts the bovine at a huge risk of developing BRD. Therefore, practicing stress reduction methods such as avoiding heat stress by not letting the cattle work for long hours during the hot season, spraying down surfaces before processing to reduce dust, castrating bull calves early, and lowering stress during transportation can be highly beneficial for the cattle.

3. Vaccinating the cattle- Your herd health plan should include inoculating the cattle with respiratory vaccines for viral and bacterial pathogens.

4. Proper colostrum intake- It is important to feed calves with colostrum if they have not nursed within four hours of birth or have a week of suckle reflux.

Early treatment for BRD leads to better outcomes. It is important to follow your veterinarian’s treatment recommendations properly whilst simultaneously working with them to assess herd risk factors and adjust herd management practices to reduce risks and control the spread of the disease. Remember to separate the affected cattle and monitor their progress closely.

Poor management while treating BRD can hamper production significantly. For instance, heifers who were not treated properly showed a reduction in conception rate and a reduction in the first lactation milk yield. Keep a close eye on the cattle for early detection of the disease. Also, prepare a structured programme for treatment and monitor the cattle for proper treatment.