Infectious bovine rhinotracheitis

Cow with infectious bovine rhinotracheitis

What to look for

Varies from outbreaks of mild disease through to severe illness.

  • Respiratory signs and fever
  • Clear discharge from their nostrils which may become cloudy and profuse
  • Drop in milk production
  • Inflamed eyes
  • Ulcers in the mouth
  • Laboured breathing
  • Not fatal unless there are complications such as bacterial infections


A herpesvirus.

Animals likely to be affected

Most often seen as an outbreak in two year old cows but can occur in any age group. Outbreaks may be triggered by stressful situations such as transport or crowding.

Other diseases with similar signs

BVDV/Mucosal disease.

Confirming the diagnosis

Virus can be isolated from swabs of infected animals. Two blood samples collected several weeks apart can be tested to see if the level of antibodies to IBR increases.

Spread of the disease

The IBR virus is usually passed from cow to cow without causing disease. If a group of animals that have not previously encountered the virus and are stressed by such things as transport or introduction to the dairy herd an outbreak may occur. Animals usually stay infected with the virus for life and can spread it to animals that have not previously been exposed.


Treatment is usually not required unless animals are seriously ill. If so, they should be isolated, given good nursing support and anti inflammatories. If bacterial infections are suspected, treat animals with antibiotics.

Risk factors

  •  Introducing cattle from outside the herd
  • Transportation, overcrowding or other stresses


Maintaining a closed herd reduces the risk of introducing IBR virus but the virus is widespread in cattle populations and may be present in herds without clinical disease. If an outbreak occurs, isolate infected animals to reduce the spread of the virus to vulnerable animals. Vaccines can be used to if there is reason to believe that animals are vulnerable to IBR e.g. entering a feedlot.

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