Infectious bovine rhinotracheitis (IBR) is a highly infectious disease in cattle caused by bovine herpesvirus 1 (BoHV-1).
It is a widespread problem within Irish agriculture with evidence to suggest that 75% of cattle herds have been exposed to the virus, according to Animal Health Ireland (AHI).
IBR
IBR is typically spread by close contact between animals – airborne spread is also possible at a distance of up to 5m.
Other ways it is spread is through contaminated semen, equipment and people.
Symptoms of an infection are dullness and reduced appetite; high temperature; rapid and loud breathing – sometimes with coughing; fluid discharge from nose and eyes; inflammation of the throat; and on occasion, death.
Infection can also be accompanied by sudden reduced milk-production, abortion or nervous signs (normally only in young calves).
The infection within the herd can also be subclinical and still have an impact in reduced milk yields and reproductive outcomes.
Cost
In dairy herds, IBR infections can have a negative impact on production, particularly when the virus is newly introduced and has the biggest impact on susceptible cattle.
According to AHI, several studies have investigated the impact the virus has on milk production.
An Irish study looking into the impact of reduced yields from infected herds, determined that profitability was reduced by an average of €60/cow/year.
Control
Controlling IBR in a herd usually requires a long period of time – this is because infected animals become latent carriers for life.
A reduction in the spread of the virus can be achieved by selective culling and vaccinations. Animals that have be identified as a potential source of the virus should be removed from the herd.
Observing strict biosecurity measures will help to prevent the possible introduction of an infected animal into your herd. Newly purchased animals should be quarantined until proven to be negative for the virus.
It is also important to maintain good perimeter fencing to prevent contact from neighbouring cattle.
Vaccinations play a key role in the control of IBR with your herd. It is important to note however, that vaccinating an already infected animal will not remove the infection.
Vaccinations should be completed in line with manufacturer’s instructions. This reduces the likelihood that a non-infected animal will become infected.
Continuous monitoring of IBR infection within your herd is recommend and a screening programme should be put in place in conjunction with advice from your vet.