Impact of bovine coronavirus (BCoV) on calf health

BCoV is a pneumoenteric RNA virus that infects both the upper and lower respiratory tract and the intestines. Clinical signs of BCoV infection include calf diarrhoea, respiratory disease and winter dysentery¹.

BCoV is a notable concern in calf health, impacting both the respiratory and digestive systems. Recent analysis of UK BRD diagnostics indicates BCoV is the most reported virus identified on-farm in routine screening and in the face of an outbreak.²

Additionally, a recent sixteen country European study found every farm was seropositive for BCoV and herds containing BCoV-seropositive calves had an increased risk of suffering BRD outbreaks³.

BCoV is a multifaceted pathogen affecting both the respiratory and digestive systems. In the respiratory system, it can lead to severe pneumonia, often opening the door to secondary bacterial infections⁴. In the digestive systems, it’s a known cause of diarrhoea and enteric diseases. Understanding its dual impact is crucial for effective calf management and disease prevention.

BCoV is incredibly widespread due to three key reasons:

1. Carrier animals – Asymptomatic animals sheds the respiratory and enteric virus which serves as a source of infection to other animals on the farm.⁵

2. Shedding – Peak clinical signs including respiratory rate/fever, appeared more than a week after shedding starts.⁶

3. Fomite transmission – Infective BCoV was found on rinsed and visually clean fomites after 24 hours, indicating they could be vehicles for transmission.⁷

Diagnosing bovine respiratory diseases involves a combination of clinical examination and laboratory testing. Techniques like PCR testing and thoracic ultrasound play a crucial role. PCR testing helps us detect the presence of pathogens like bovine coronavirus, while thoracic ultrasound gives us a clear view of the lung health in calves, identifying any abnormalities or infections.

These techniques, when used together provide a comprehensive understanding of the calf’s health status, enabling targeted treatment and prevention strategies.

Disease prevention in calves requires a multifaceted approach. It begins with ensuring good colostrum intake, maintaining excellent hygiene and housing conditions, and implementing stress reduction strategies. Vaccination, such as BOVILIS NASALGEN^®-C, plays a vital role, but it must be part of a broader herd health management plan that addresses all aspects of calf health and welfare.

BOVILIS NASALGEN^®-C is an live intranasal vaccine that can used for the active immunisation of cattle from the day of birth onwards, to reduce clinical signs of upper respiratory tract disease and nasal viral shedding from infection with BCoV.

It can be used from the day of birth, with onset of immunity five days after vaccination with a 12-week duration of immunity. Administered via a single 2 ml intranasal dose, it comes in 5 x 1 dose, five and 20-dose packs. It’s suitable for small and large herds and can be given to cattle using a syringe or applicator device.

Carrying out diagnostics to identify whether BCoV is implicated in any BRD issues, and talking to your vet about factors such as hygiene and colostrum management, will help to make any necessary adjustments before implementing a vaccination programme – which will give the vaccine the greatest chance of success.