Helping to keep our herds free of IBR

The potential cost of Infectious Bovine Rhinotracheitis (IBRV) in a herd — even if there are no clinical symptoms — can be substantial in certain circumstances, according to the Animal Health Ireland organisation.
Helping to keep our herds free of IBR

IBRV represents an ongoing risk to semen collection centres, and significantly restricts the number of animals eligible for entry into these centres, consequently reducing the pool of genetic material for selective breeding.

Many international agricultural shows impose restrictions against IBR.

IBR-infected animals and semen cannot be traded to many regions (including Denmark, Germany, Austria, Finland, Sweden, Norway, Switzerland, regions of Italy and the Czech Republic).

AHI has recently updated key information on tackling the disease on its website.

AHI is the not-for-profit partnership between farmers, processors, animal health advisers and government to combat those livestock diseases not subject to official control measures.

Q&A WITH ANIMAL HEALTH IRELAND

How common is IBR in Irish beef and dairy herds?

Between 70% and 80% of all Irish herds contain at least one animal infected with IBR. Some infected herds may have only a single infected animal.

More commonly, many animals are infected, and in some cases all animals can be infected.

How should I manage an animal with IBR?

Veterinary examination of suspected cases is essential if you have an animal showing signs consistent with IBR.

There are several other diseases that cause similar signs (dullness and reduced appetite, high body temperature, rapid and loud breathing sometimes with coughing, inflammation inside the nose and in the pink of the eye or less commonly on lining of reproductive tracts, fluid discharge from nose and eyes, inflammation of the throat, sudden reduced milk production, abortion, nervous signs in young calves, marked respiratory disease, death or long-term ill-health in severe cases.

An animal can be infected with IBR (and test positive) even if it has never had the typical signs of disease.

If a diagnosis of IBR is made, the vet may advise immediate isolation and vaccination of the sick and ‘at-risk’ animals.

There is no treatment (or vaccination) that can remove latent infection from an animal.

How does IBRV spread?

Direct contact (eg nose to nose) is the most important method.

The virus can also spread between animals over short distances in air.

It is highly contagious; single animals shedding IBR can infect as many as seven more susceptible in-contact animals.

How do I stop IBR from coming into my herd?

The risk can be controlled by implementing a bio-exclusion plan in conjunction with your vet.

Introducing stock is the highest risk activity, followed by activities that allow direct or close contact between your own animals and animals from outside your herd.

Next. address moderate risk ‘indirect contact’ activities, such as visitors with contaminated clothing, contaminated farm equipment or vehicles from another herd, feeding colostrum from other herds of unknown IBR status.

What tests are available to investigate IBR?

Tests to detect the virus are normally used only to confirm infection in an animal with clinical signs.

Tests for antibodies can determine if an animal has been previously exposed to IBR (and can be presumed to be latently infected).

This information can be used in pre-purchase testing and screening or monitoring herd infection status.

Herd tests for IBR typically use antibody based tests.

How do I decide whether to start a control programme for IBR in a herd?

This depends on your specific herd goals, clinical impact, and sub-clinical impact.

What different options are available to control IBR in a herd?

Three principles are commonly implemented — bio-exclusion (stopping the virus from coming into your herd); isolation/culling of latent carriers; and vaccination.

In medium or high-prevalence herds, vaccination with bio-exclusion is the most practical and appropriate option.

All control programmes should be monitored to make sure they are working.

How do I decide whether or not to vaccinate a herd for IBR?

A vaccine improves the immunity of an animal.

It can reduce clinical signs, reduce reactivation and spread from latent carriers, and provide herd immunity. Animals must not be vaccinated if they are to enter a semen collection centre or bull testing station.

What is the risk of introducing IBR with semen purchased from an AI centre?

Risk from semen originating in the Republic of Ireland is negligible.

Other countries within the EU (including the UK) have allowed semen collection centres to operate without IBR freedom.

Semen from such centres cannot be legally imported into the Republic of Ireland.

Can humans be affected by IBR?

It is not a disease of humans.

Is there a national programme for IBR control in Ireland?

In 2013, there is no national control programme.

AHI is working with all industry stakeholders to investigate options for a national approach to IBR control.

Benefits of eradication would include elimination of clinical and sub-clinical disease, improved animal welfare, substantially extending the genetic pool of animals available for entry into semen collection centres.

*For full details, see the below document.

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