Calf Pneumonia: Prevention, Welfare and Management

Bovine Respiratory Disease in Calves

Calf pneumonia (bovine respiratory disease, BRD) is the most common and economically damaging disease of young cattle in the UK and worldwide. It causes significant animal suffering, impairs long-term productivity, and is responsible for more antibiotic use in cattle than any other condition. Addressing BRD effectively requires understanding its multifactorial nature — it is not simply an infectious disease but a complex interaction of calf immunity, pathogen exposure, and environmental stressors.

Welfare Impact

Pneumonia causes significant pain and distress in affected calves:

Fever, malaise, and lethargy from systemic infection
Chest pain from pleuritis (pleural inflammation)
Respiratory distress — laboured breathing, nasal discharge, coughing
Reduced feed intake accelerating nutritional decline
Long-term lung damage reducing productivity in survivors

Studies using pain scoring scales confirm that calves with BRD experience moderate to severe pain. Early recognition and prompt treatment are welfare priorities.

Risk Factors: The "Pneumonia Pyramid"

Host Factors

Poor passive immunity transfer (inadequate colostrum)
Stress from weaning, transport, or mixing
Nutritional deficiencies (selenium, vitamin E, copper)

Pathogen Factors

Mannheimia haemolytica, Pasteurella multocida (bacterial)
BRSV, BPI-3, BHV-1 (viral triggers)
Mycoplasma bovis (increasingly important, antibiotic-resistant)

Environmental Factors

Poor ventilation (ammonia, humidity, pathogen load)
Overcrowding and excessive mixing of age groups
Chilling and draughts at calf level

Prevention Strategies

Ensure adequate colostrum — 10% bodyweight within 2 hours of birth
Test passive immunity transfer (serum total protein or zinc sulphate turbidity test)
Optimise housing ventilation — 4-6 air changes/hour without draught
Use all-in/all-out management for calf groups
Vaccinate for BRSV, BPI-3, and Mannheimia following veterinary protocol
Provide deep, dry bedding (kneel test — knees must stay dry after 30 seconds)

Recognition and Treatment

Early treatment significantly improves outcomes and reduces suffering. Use a validated scoring tool (Wisconsin Calf Respiratory Scoring Chart):

Score nasal discharge, eye discharge, ear position, head posture, and cough
Score ≥5 requires treatment; score 4 requires re-evaluation in 24 hours
Prompt NSAIDs (meloxicam) alongside appropriate antibiotics reduces pain and improves recovery speed

Antibiotic Stewardship

BRD is the leading driver of antibiotic use in cattle. Responsible use requires veterinary diagnosis, culture/sensitivity where indicated for recurrent outbreaks, and selection of narrow-spectrum agents where appropriate. Reducing BRD incidence through improved management reduces antibiotic dependence.