Infectious bovine rhinotracheitis (IBR) is a disease of the upper respiratory tract caused by the virus, bovine herpesvirus 1 (BHV-1). It is highly contagious affecting cattle of all ages. It is commonly seen in young and naïve cattle and has been described as one of the top cattle health and welfare concerns in the UK.
IBR is reported to cost the industry £36.6m annually
The clinical signs of IBR vary. Acute infection commonly causes overt symptoms such as rhinitis, tracheitis and conjunctivitis. Although clinical IBR is seen infrequently now and it is more the chronic, long term effects that are causing problems on farm such as reduction in milk yields, infertility and pneumonia.
Latent IBR infection is believed to develop in almost all animals infected with IBR, with the virus often remaining dormant for long periods until times of stress induce virus shedding.
The virus can readily spread to naïve and untreated cattle through direct contact, airborne infection and contaminated materials and equipment. As a disease that can spread easily between cattle, it is vital biosecurity measures and vaccinations are implemented to minimise the risks from IBR.
Active infections are diagnosed by direct detection of the virus via PCR or fluorescent antibody tests on ocular or nasal secretions. Diagnosis of latent infections can be made via serology (blood samples).
The IBR status of a dairy herd can be determined by measuring bulk milk antibody titres, although caution is advised because a negative bulk milk result does not necessarily indicate a herd is IBR-free.
IBR risk factors
- Introducing new animals to the farm
- Nose-to-nose contact between infected and non-infected animals
- People and equipment
- Semen and embryos
- Latent carriers becoming stressed through stock movements, housing and/or calving
- Transmission by contact with mucosal droplets from infected cattle (Kahrs RF. 2001. Viral Disease of Cattle. 2nd ed. Ames, IA: Iowa State University Press; p.159-170)
- Transmission to susceptible animals through contaminated materials including semen (Mars et al. Vet Microbiol 200; 76:1-13.)