Bovine viral diarrhoea – London Borough of Bromley

Bovine viral diarrhoea (BVD) occurs worldwide and can affect cattle of all ages

In this guide, the words 'must' or 'must not' are used where there is a legal requirement to do (or not do) something. The word 'should' is used where there is established legal guidance or best practice that is likely to help you avoid breaking the law.

This guidance is for England

Bovine viral diarrhoea (BVD) can have very varied symptoms from inapparent infection to severe enteritis, abortion and death. It can have substantial impact on the profitability of farms. This highly contagious disease has been estimated to cost between £13 and £31 per cow in Great Britain. It impacts animal welfare within affected herds and reduces farm productivity and profitability.

Control and prevention can be achieved through improved biosecurity and vaccination.

CLINICAL SIGNS

Clinical signs can vary greatly, such as a bout of diarrhoea or pneumonia (often in a group of animals), or an increase in abortions / stillbirths and a decrease in fertility and lower conception rates. BVD can also cause return to heat, embryo deaths, deformities and weak or premature calves.

Calves contracting the disease while still in the womb can be born as 'persistently infected' animals (PIs*). Such animals continue to excrete the virus throughout their lives and are therefore the greatest risk of spread of infection. These animals, as well as failing to thrive, tend to have impaired immunity, making them more susceptible to other diseases. They are likely to die before reaching maturity. Cattle infected after birth can recover from BVD, but do suffer from a reduced ability to fight other infectious diseases.

[*For ease of reference, all animals that are BVD positive are referred to in this guide as PIs.]

BVD is spread via contact with infected cattle, particularly PIs. A thorough BVD testing regime, movement restrictions and good biosecurity controls are required to eradicate this disease.

BVD TESTING

In England, the BVD eradication programme remains voluntary and is not supported by legislation. BVD schemes in Wales, Scotland, Northern Ireland and the Republic of Ireland have statutory requirements and are backed by legislation, as BVD is one of the biggest disease issues affecting the cattle industry.

In England, the BVDFree England was the national, voluntary, industry-led scheme; it had the aim of eliminating BVD. The scheme was set up with the backing of the National Farmers Union, National Beef Association, Holstein Group, British Cattle Veterinary Association, Livestock Auctioneers Association and the levy funded Agriculture and Horticulture Development Board (AHDB). The BVDFree England Board took the decision to close the BVDFree England Scheme on 31 July 2024.

The scheme led to the co-design of the new Animal Health and Welfare Pathway England (the Pathway). Keepers can now receive funding for their chosen vet to visit their premises and carry out a health and welfare review, including help to reduce endemic diseases and conditions. More information on eligible funding and how to apply can be found on the GOV.UK website.

Whilst there is currently no legislation specifically for the control of BVD in England, there are supporting schemes such as Red Tractor Dairy, which requires farmers to have a BVD elimination plan in place or a CHECS accredited scheme. The Code of Recommendations for the Welfare of Livestock: Cattle (see paragraph 24) indicates that the written health and welfare plan should, as a minimum, cover specified diseases, of which BVD is one.

All herds enrolled under a CHECS scheme must declare the results of any screening carried out during the previous 12 months to either their own veterinary surgeon or a health scheme provider. The full requirements are detailed in the CHECS technical document (see link in 'Further information' below).

Control options can include 'tag and test', check testing of youngstock, milk testing in dairy herds and vaccination. Check test sampling needs to be completed before vaccination to avoid erroneous results.

The AHDB website contains information on BVD testing and control routes. By law, cattle must be identified with a pair of approved ear tags that correlate with the cattle passport. Tissue sampling tags can be ordered from your usual tag supplier and are used in place of one of the approved tags, usually the secondary tag.

Any blood samples must be taken and submitted by a veterinary surgeon. All samples taken under the Pathway must be sent to a designated lab. Under the Pathway, the designated veterinary surgeon will provide a report including the endemic disease or condition test results from the laboratory.

BVDFree England issued a certificate based on the individual animal BVD status. For herd BVD status, BVDFree England issued a certificate based on the tag and test status (for virus) when all calves born test negative for two years minimum or where youngstock (minimum of five unvaccinated animals per management group at 9-18 months age) are blood sampled (for antibody). With the closure of BVDFree England keepers are able to contact bvdfree.certificates@ahdb.org.uk for any queries or access to herd status certificates.

HERD STATUS AND MOVEMENT RESTRICTIONS

Ultimately, BVD elimination will only happen with support and a coordinated approach from farmers, veterinary surgeons and the agriculture industry.

Under CHECS, there are three standard programmes for BVD:

Accredited Free (AF) Programme. Demonstrating that the herd is free from BVD
Vaccinated Monitored Free (VMF) Programme. Demonstrating that BVD is controlled through vaccination of the breeding herd and by regular monitoring of young stock
Eradication Programme. Implements a control programme to reduce the detrimental effects on herd productivity caused by the disease and to achieve freedom from the disease

To maintain the status, under CHECS, check tests are carried out on successive calf crops. Where animals have been confirmed as PI, they must not be sold on, except to slaughter. CHECS also requires movements off the farm to meet specified conditions, such as being kept separate from non-accredited cattle. The full requirements are detailed in the CHECS technical document.

For BVDFree England, the herd status had to be renewed each year and was dependent on the most recent test results. BVDFree England had set a variety of statuses, with different meanings; these will still appear on valid certificates:

BVD Virus Test Negative. Cattle are not pregnant and are either:
- from a BVD accredited-free herd through a CHECS cattle health scheme
  or
- individually tested BVD virus-free
BVD Low Risk. From a herd with a 'negative' BVD herd status through animal screening OR pregnant cattle that would otherwise be in the above category
BVD Status Unknown. All cattle not in the above two categories (including from 'not negative' herds)
BVD Virus Test Positive. All cattle for which the most recent BVD antigen test is positive. Animals subsequently retested as BVD antigen negative can be reclassified as BVD Virus Test Negative

MINIMISING RISK

PI animals are highly infectious and should be culled as soon as they are identified. PI animals should not be traded. Other cattle in the herd may be transiently infected, although they can be traded if not identified as a PI.

Spreading the BVD virus through movement of the animal puts other herds at risk and undermines the national effort to eliminate the BVD virus from England.

Means of reducing risk include:

check the BVD status of any animals you bring on to your holding.
practise good biosecurity
avoid buying in pregnant animals, as calves that contract BVD in the womb can become PIs for BVD. Also avoid taking pregnant animals to shows
avoid nose-to-nose contact with cattle from neighbouring holdings
vaccination may be an option, but this should be discussed with your vet

CAN PEOPLE CATCH THE DISEASE?

BVD is not known to affect humans, but good hygiene procedures should always be followed after contact with livestock.

COULD IT AFFECT THE FOOD I EAT?

No, it does not affect the food we eat and it cannot be contracted by consuming beef or dairy products.

FURTHER INFORMATION

More detailed guidance is available from AHDB and CHECS.

TRADING STANDARDS

For more information on the work of Trading Standards services - and the possible consequences of not abiding by the law - please see 'Trading Standards: powers, enforcement and penalties'.

IN THIS UPDATE

New AHDB contact email address added.

Last reviewed / updated: October 2024

Key legislation

Please note

This information is intended for guidance; only the courts can give an authoritative interpretation of the law.

The guide's 'Key legislation' links may only show the original version of the legislation, although some amending legislation is linked to separately where it is directly related to the content of a guide. Information on changes to legislation can be found on each link's 'More Resources' tab.