Unit 6: Health and Welfare of Beef Cattle

Pneumonia

Pneumonia in beef cattle, often referred to as bovine respiratory disease (BRD), is one of the most common and economically significant diseases in the cattle industry.

Causes

BRD is typically triggered by several factors, including:

Infections

Bovine Herpesvirus-1 (BHV-1): Causes Infectious Bovine Rhinotracheitis (IBR), causing cattle to have bacterial pneumonia.

Bovine Viral Diarrhoea Virus (BVDV): Suppresses the immune system, making cattle more vulnerable to secondary bacterial infections.

Bovine Respiratory Syncytial Virus (BRSV): Directly damages lung tissue, leading to severe pneumonia.

Environmental and Management Factors

Weaning stress: Calves are particularly vulnerable to pneumonia during and after weaning due to stress.

Transportation stress: Mixing with other animals, and poor ventilation during travel can weaken the immune system.

Weather: Cold, wet, and windy conditions increase the risk.

Overcrowding and poor ventilation in sheds.

Symptoms

Fever: Body temperature above 39.5°C.

Heavy breathing: Coughing, nasal discharge, and rapid breathing.

Appearance: Lethargy, reluctance to move, droopy ears, and separation from the herd.

Loss of appetite: Cattle may refuse to eat, leading to weight loss and poor growth rates.

Coughing: Frequent or loud coughing is common in infected cattle.

Treatment

Antibiotics: Bacterial pneumonia is treated with antibiotics.

Supportive Care: Providing adequate nutrition, water, and minimising stress can help recovery.

Early intervention: Treating animals early in the disease process is critical to improving outcomes.

Preventions

Vaccination: Vaccination against viral pathogens (BHV-1, BVDV, BRSV, and PI-3) and bacteria (M. haemolytica and P. multocida) are the best preventative treatments.

Environmental Controls: Ensure good ventilation, avoid overcrowding, and provide shelter during extreme weather conditions.

Biosecurity Measures: Limiting animal contact with outside cattle and proper quarantine of new animals can help prevent the introduction of diseases.