The Bovine Viral Diarrhoea (BVD) Eradication Scheme phase 4: guidance for vets

Part 2 The Scottish Bvd Eradication Scheme

Key features of new legislation (phase 4)

• Any animal from a herd with a 'not negative' BVD status will not be able to move unless individually tested negative for BVD virus or moving directly to slaughter.
• Animals brought into a herd from an untested herd will have to be individually tested for BVD virus. This will include imported animals along with any from non-breeding herds.
• A reduction in the number of testing options available to three for 'negative' herds and two for 'not negative' herds. This will see the removal of all bulk milk tests and the introduction of a new dairy check test.
• Assumed status - The calf of a PI mother will be assumed to be PI and the mother of a BVD virus negative animal will be assumed to be BVD virus negative.

Continuing Measures

• Every keeper of a breeding cattle herd must continue to screen their herd annually.
• Animals identified as positive for BVD virus cannot move other than directly to slaughter.
• Screening samples must be sent to an approved laboratory along with the required information.
• The laboratory should declare a herd status as 'negative' or 'not negative', depending on the outcome of testing. Laboratories must inform the Scottish Government of all BVD test results whether for an official screening test or not.
• The laboratory must also inform the keeper of BVD test results.

Not negative herds

The purpose of the BVD eradication programme is to identify and remove Persistently Infected ( PI) animals from the national herd. 'Not negative' herds have evidence of exposure to the disease, therefore more thorough testing is required to identify if there are PI animals present. If a keeper has a 'not negative' status they should use either a calf screen or a whole herd screen as their annual test. Only animals that have tested negative for BVD virus or those assumed to be negative can move from 'not negative' herds.

Restrictions on bovine animals from untested herds

If a keeper brings an animal into a breeding herd from an untested herd, be that a non-breeding herd or it is an imported animal, the animal must tested for BVD virus on arrival. The status of the receiving herd will change to 'not negative' until a negative test result has been received for the animal. The brought in animals should be isolated from the rest of the herd until the result has been received.

Untested herds

If a keeper does not test annually their herd will be given a status of 'not negative' and the restrictions for 'not negative' herds will apply.

Mandatory screening for breeding herds

Keepers of breeding herds of cattle in Scotland must continue to have their herds screened every year for BVD.

What is a breeding herd for the purposes of the legislation?
A herd is defined in the BVD Order 2013 as a breeding herd if breeding is planned or allowed to happen. There is no set number of births or cattle that are needed to constitute a breeding herd - one cow used for breeding is enough.

How must they be screened?
Three minimum testing methods are now available, and these are set out in full in Part 3. These are the minimum requirements; it will often be in your clients' interests to do more than this and we recommend that you advise appropriate follow-up testing in a herd with a 'not negative' status in order to identify any PI animals that may be in the herd.

Non-breeding herds

For any other type of cattle herd, such as a finishing herd, any calves born are required to be tested for BVD virus within 40 days of birth. This would usually be by tissue test but the laboratory would be able to tell you from what age they would accept a blood sample.

Assumed status

Animals which have been individually tested for the BVD virus will have a result of either positive or negative.

If they are negative, these animals are able to move because a negative animal can never become PI.

Phase 4 will introduce an assumed status for some animals. The mothers of any individually negative animals are also safe to move. A PI mother cannot give birth to a virus negative calf and therefore if a calf is BVD virus negative its mother will have an assumed individual status of BVD virus negative. If you have to individually test animals to move them, where a calf has a negative result, the mother will be given an assumed negative result and can also move.

If the result is positive the animal is a suspect PI, it cannot move other than directly to slaughter. A PI mother can only give birth to a PI calf and therefore any calf born to a PI cow will be assumed to be PI and cannot move other than directly to slaughter. You should retest any positive animal after three weeks to ensure that the animal was not suffering from a transient infection.

Persistently infected ( PI) animals

Any animal that tests positive for BVD virus will be identified in the database as virus positive and will be assumed to be PI until a subsequent test can show that the infection has been transient. To ensure that an animal is not transiently infected it should be retested after three weeks. If on the second test the animal is virus negative it may move again.

PI animals are only permitted to be moved off the farm if going directly to slaughter. In exceptional circumstances, such as for immediate welfare issues, a veterinary inspector may allow an infected animal to move under licence through applying to the Animal and Plant Health Agency ( APHA).

BVD virus infected animals may not pass through a market or any other holding. The Scottish Government will be informed by the laboratories each time an animal tests positive for BVD virus, and will know through movement records if a virus positive animal is moved to another holding.

The BVD look up and herd declarations

The Scot EID website at www.scoteid.com is the central point at which all BVD results can be found. All approved laboratories report their results directly to the Scot EID database. You can find the status of any herd and the result of any individual animal tested if you have the County Parish Holding ( CPH) and individual animal number. Help on how to use the BVD lookup facility is provided on the Scot EID website or through the BVD helpline on 0300 244 9823.

• You should contact the helpline to register with Scot EID. Registering with Scot EID will allow you to:
• See all of the BVD results for your clients.
• Search for a specific CPH or animal ID.
• See a list of all calves born and all current cattle on the holding and whether these have been tested.
• See clients' renewal dates and status.
• All tissue test results (where your client has provided a vet postcode).

This will give you the ability to change a herd status where appropriate and identify what further testing may be required.

In phase 4 mandatory herd declarations are not required as animals should not move from a 'not negative' herd unless they have been individually tested for the virus. However, farmers should continue to use the BVD lookup to ensure any animals that are to be purchased are from negative herds or have had a negative virus test. If animals are purchased from a 'not negative' holding the receiving holdings status could be affected.