As the winter approaches and calves are now starting to be housed in barns it is important to be aware of the affect pneumonia or Bovine Respiratory Disease (BRD) can have on your herd.
BRD is a complex disease which results in inflammation and damage to the tissues of the lungs and respiratory tract. It is the most common reason for poor performance and death in growing calves. If affected it can impact a calf for its entire life leading to reduced growth rates and lower milk yields. Autumn-born calves are generally more severely affected than older spring-born calves. BRD is also a major animal welfare concern which is best prevented by a combination of good management, effective vaccination and appropriate housing
The majority of outbreaks start with a virus, the key ones being:
- Parainfluenza 3 (PI3)
- Respiratory Syncytial Virus (RSV)
- Mycoplasma bovis
Bovine Viral Diarrhoea (BVD) and Infectious Bovine Rhinotracheitis (IBR) are also important viruses to consider as they will reduce calves’ immunity to the above viruses.
Clinical signs of calf pneumonia include:
- A temperature of greater than 39.5 °C
- Increased breathing rate and effort
- A nasal discharge which is initially clear and watery, but becomes thick and pus-like as the disease progresses
- Reduction in feeding
- Dropping of the head
- Dull demeanour
During the early stages of infection calf pneumonia can be difficult to detect. An elevated temperature is the first sign of disease and typically occurs 12-72 hours before detectable clinical signs appear.
The aim of pneumonia prevention is to support a calf’s immune system and reduce exposure to stress through good husbandry. While the risk of disease can never be fully eliminated, implementing preventive measures can reduce the impact of disease. Areas to focus on are:
- Good colostrum management
- Low stocking density
- Low housing humidity
- Adequate ventilation
- Avoiding extremes of temperature
- Good nutrition
- Separating age groups
- Sound hygiene
- Minimising stress when transporting, weaning, castrating and disbudding
- Sick animals should be separated as quickly as possible as they can shed huge amounts of infectious organisms into the air space that other calves will breathe, so becoming a key source of infection.
- Fast and effective antibiotic treatment is critical for minimising potential lung damage. Providing treatment with a long-acting NSAID alongside antibiotics will often improve the demeanour of a sick calf, which can result in a quicker return of appetite and recovery.
- Vaccination helps protect against pneumonia by increasing an individual calf’s immunity.
- Pneumonia vaccination is associated with higher heifer weights at 8 months as vaccinated calves weighed over 45kg more than unvaccinated calves.
- Many vaccines are available to protect against pneumonia. Ask our vets which ones are right for your herd. Selecting the correct vaccine to protect the right age calves against specific pathogens is critical.
- If you have an outbreak of pneumonia it is important to act quickly. Our vets can help you implement a treatment and management protocol specific to your farm’s requirements.
- Air should appear fresh and free of ammonia or slurry smells when you walk through the barn especially during still winter nights.
- Fresh air should be available just above the calves whilst avoiding draughts at calf level.
- Ensure adequate drainage to prevent high humidity. Condensation on underside of roof and cobwebs over outlets are indicators of poor ventilation.
- Bedding should be clean and dry and ideally deep enough for young calves to nest in, lie down and stretch their limbs.
- Over stocking should be avoided.
- Adequate space for feeding and water troughs should be provided.