Dr Kat Baxter-Smith, MSD Animal Health
Coronavirus Link Highlights Need To Strengthen Calf Respiratory Disease Protection
2 months ago 
508 views
New screening data has highlighted the importance of protecting calves against bovine coronavirus as part of a wider strategy to prevent bovine respiratory disease (BRD).
Analysis of 1,732 calves screened through MSD Animal Health’s BRD screening service* between 2022 and 2026 found that 69.5% had antibodies to bovine coronavirus¹.
Coronavirus-positive groups were also significantly more likely to show evidence of other respiratory pathogens, particularly bovine parainfluenza virus type 3 (PI3) and Mannheimia haemolytica¹. Each additional PI3-positive calf was associated with an approximately 37% increase in the odds of a group being coronavirus-positive¹.
“Seeing evidence of multiple pathogens within the same groups reinforces that BRD is rarely caused by a single pathogen. It highlights the need for farmers to take a proactive, whole-farm approach to respiratory disease prevention,” says MSD Animal Health Veterinary Adviser Dr Kat Baxter-Smith.
Bovine coronavirus may play a role early in the disease process by affecting the protective lining of the respiratory tract, potentially making it easier for other pathogens to contribute to disease.
Protection against respiratory coronavirus can start from day one, with Bovilis Nasalgen®-C, an intranasal vaccine that can be administered to calves from the day of birth. It is licensed to reduce clinical signs of upper respiratory tract disease and nasal viral shedding associated with bovine coronavirus infection.
“For farms where coronavirus is identified as part of the respiratory disease challenge, having the option to protect calves from the day of birth can be an important part of a wider prevention strategy,” says Dr Baxter-Smith.
Importantly, the absence of obvious respiratory signs does not necessarily mean calves are healthy. While clinical BRD typically affects around 11–16% of calves, subclinical disease, where lung damage occurs without obvious signs, may affect 23–67%².
“By the time coughing, nasal discharge or increased respiratory effort become apparent, lung damage may already have occurred,” says Dr Baxter-Smith.
Even small lung lesions can affect performance, with research showing calves with 1–2cm lesions can have average daily gains 96–138g lower than calves without lesions³.
“This is why understanding which pathogens are circulating and identifying risk factors on farm is so important,” adds Dr Baxter-Smith.
“Vaccination, alongside good colostrum management, nutrition, housing, ventilation and hygiene, can all contribute to reducing the risk of respiratory disease.”
Prevention starts before disease strikes
BRD screening can help identify pathogen exposure and potential gaps in protection, while thoracic ultrasound (TUS) can identify lung damage and subclinical disease.
MSD Animal Health offers vaccines covering key BRD pathogens, including respiratory coronavirus, BRSV, PI3, M. haemolytica and IBR.
“Vaccination is not a silver bullet for respiratory disease, but it is an important part of a wider prevention strategy,” says Dr Baxter-Smith.
“BRD results from a combination of infectious challenge and other risk factors, so prevention needs to focus on both reducing exposure and supporting the calf’s ability to withstand disease.”
With respiratory disease often becoming more challenging during the autumn and winter months, farmers and vets are being encouraged to review their BRD prevention plans now, ahead of winter housing, and consider whether current vaccination and management strategies are providing adequate protection.
BRD Webinars
MSD Animal Health will be exploring the latest thinking around BRD in a webinar on Monday 14 September, featuring a farmer who is actively using thoracic ultrasound scanning as part of BRD management. Find out more and register here
https://incisivemedia.zoom.us/webinar/register/WN_JvkJDq_yTXyFR1yZs9pWIA
The Webinar Vet will also host ‘BRD in Practice: Prevention, Diagnostics and Emerging Risks’ on Tuesday 22 September exclusively for vets. Register now > https://thewebinarvet.com/webinars/brd-in-practice-prevention-diagnostics-and-emerging-risks
*MSD Animal Health’s BRD Screen service is a subsidised service available through most GB veterinary practices. It uses blood samples from a small selection of calves aged three to six months to assess exposure to five major BRD pathogens.
References
- MSD Animal Health BRD Screen data, 2022–2026.
- Ollivett, T.L. & Buczinski, S. (2016). On-Farm Use of Ultrasonography for Bovine Respiratory Disease. Veterinary Clinics of North America: Food Animal Practice, 32(1), 19–35.
- Tejero, C. & Bach, A. (2016). The hidden cost of a hidden disease: growth performance of calves as affected by bovine respiratory disease diagnosed using ultrasonography. Journal of Animal Science, 94(5).
More from MSD Animal Health
- Free Webinar Exploring the Transition Cow Connection to Better Calf Colostrum
- Farmers Urged to Act Now as Sheep Face Lameness ‘Double Whammy’
- More Farmers Testing Colostrum Quality as Focus on Calf Immunity Grows
- FlockCheck Results Highlight Continued Abortion Disease Risk Ahead of Tupping
- EID, Herd Monitoring Tech and Proactive Herd Health Protocols on Show at Demonstration Farm Open Day