What is IBR?
Infectious Bovine Rhinotracheitis is an infectious viral disease of cattle that is contagious. It belongs to a family of viruses called herpesvirus. These viruses are different because they can develop latency. This means after initially becoming infected the animal may get sick or may appear clinically normal. Then the virus subsequently goes into hiding (in the nervous system) and can reactivate or reappear in times of stress. This means these animals often don’t get sick again but will shed the virus to infect other animals.
People will be familiar with the cold sore virus which acts in a very similar fashion in humans.
The virus affects the upper respiratory system of cattle. It can cause irritation and reddening of the airways and eyes. It can cause coughing and breathing difficulty. A lot of animals can become sick with the virus and will run a temperature of over 40 degrees Celsius.
It can also shed out to the bloodstream causing fertility issues and abortion.
How is it spread?
It can be spread in aerosol secretions from sick infected animals. This is usually by close contact or while sharing the same airspace. Another reason why ventilation and fresh air are so important. When controlling respiratory disease in cattle giving animals space and fresh air is so important indoors.
Adult animals shedding the disease can pose a risk to younger stock with little or no immunity.
Latently infected carriers can also shed the virus when reactivated through some stressors. They will not shed as much virus as infected animals but can be a significant source of infection. The real risk here is when we buy in these carrier animals (look healthy) they can then start shedding in the herd when becoming stressed.
This is where blood testing of bought-in stock for IBR may prove very valuable.
Some examples of these cases we have seen are where cows are bought in and at calving time start shedding.
They then can infect other cows at calving who are stressed causing significant clinical disease.
Watch our video https://youtu.be/-qZ4rxWxzUw as Farmlab vet John Gilmore discusses above the mechanisms by which IBR sheds and spreads.
IBR can cause significant issues with sick animals and disease. Not just respiratory disease, but infertility and immunosuppression.
How can we test for it?
Thankfully we have very effective tests for IBR virus in our state of the art laboratory. We can use blood samples to check for antibodies or use milk samples in dairy cows. Bulk milk screening tests are very useful for monitoring IBR levels in the dairy herd.
At farmlabs we also have a very unique PCR test that can pick up the virus on nasal swabs, This test can be used by your vet on clinical cases where there is a suspicion of respiratory disease and IBR.
We can also check the windpipe of animals we have carried out post mortems on by using PCR to check for the virus.
Talk to your vet today about sampling your herd to check for IBR status.
If your herd is IBR free then we must have very strict biosecurity to prevent the disease being bought in. This can be very difficult so most farms will incorporate vaccination as part of their control strategies.
IBR vaccination control programs work very well once the vaccine is used correctly and timed to protect animals at the greatest period of risk.
With a number of vaccination programs available talk to your vet about suitable protocols for your farm.
For more information about IBR testing, you can contact us on 071 9630792