NAVLE Respiratory

Bovine Calf Pneumonia Study Guide

Bovine Respiratory Disease (BRD), commonly referred to as calf pneumonia or "shipping fever," is the most common and costly disease affecting North American cattle.

Overview and Clinical Importance

Bovine Respiratory Disease (BRD), commonly referred to as calf pneumonia or "shipping fever," is the most common and costly disease affecting North American cattle. It is a multifactorial syndrome involving complex interactions between environmental stressors, host factors, and multiple infectious pathogens.

Aspiration pneumonia results from inhalation of foreign material into the lower respiratory tract. It requires special consideration due to its unique etiology and guarded prognosis.

High-YieldBRD is the leading cause of morbidity and mortality in beef cattle and second most common disease in dairy calves after neonatal diarrhea. Economic losses include treatment costs, reduced weight gain, decreased milk production, and mortality.
Virus Abbreviation Key Features
Bovine Respiratory Syncytial Virus BRSV Most important primary viral pathogen; syncytial cells in bronchioles; subpleural emphysema
Infectious Bovine Rhinotracheitis IBR (BHV-1) Upper respiratory; latent infection; fibrinonecrotic rhinotracheitis with diphtheritic membranes
Parainfluenza-3 Virus PI3 Usually mild; predisposes to bacterial pneumonia; impairs mucociliary clearance
Bovine Viral Diarrhea Virus BVDV Immunosuppressive; PI calves are reservoirs; lymphoid depletion

Etiology and Pathophysiology

Viral Pathogens

Viral infections initiate disease by damaging respiratory epithelium and suppressing immune defenses.

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