What is IBR?

IBR is caused by the bovine herpes virus. This virus causes three different types of disease: respiratory disease (IBR), venereal disease, and brain disease in calves. The last two are much less common than respiratory disease

Clinical Signs

  • Nasal discharge (can be clear but is often milky-white)
  • Conjunctivitis (red eyes)
  • High temperature
  • Loss of appetite
  • Dramatic drops in milk yield may be first sign
  • Difficulty in breathing and coughing may occur but not consistently
  • Death can occur in severe cases
  • Abortion is seen in some animals with clinical signs.


  • On the clinical signs described above. The signs of IBR are very variable. In some outbreaks, little more than a runny nose and red eyes is seen (although drops in milk yield can be large despite the apparently mild disease).
  • Unlike PI3 and RSV (the other two main viruses), IBR is commonly seen in adult cattle.
  • Your vet can take samples for virus testing from the respiratory tract or conjunctiva
  • Blood testing for antibodies can identify infected cattle, particularly if paired samples are taken
  • Post mortem examinations are very useful in severe outbreaks, as other disease such asPasteurella may be involved
  • Diagnosis on a herd basis can be made using a combination of blood tests and milk tests. Ask your vet for advice


  • Antibiotics are useful on preventing and treating infection by bacteria, which often develops after IBR starts.
  • Vaccination in the face of an outbreak can be beneficial in reducing its spread


  1. Biosecurity - Cattle are the main source of the virus, virtually all farms with an IBR problem have bought it in. The main source of the virus is not animals with disease but animals that have recovered from disease, as these cattle still have the virus in their body (they are 'latently' infected) You should not buy antibody positive cattle if you are IBR free
  2. Vaccination - There are several effective vaccines on the market, discuss with your vet which is the best for you.