Once TB-infected cattle have been found, milk and movement restrictions come into force.
TB-infected cattle can be found by:
- A skin test
- An interferon-gamma blood test
- Routine meat inspection at the slaughterhouse when animals are routinely sent to slaughter
- A post-mortem inspection undertaken somewhere else e.g. at a hunt kennel or on-farm
- Rarely, clinical cases where a live animal is showing signs suspicious of TB
Reactors found at a skin test
The flow diagram below summarises what happens when one or more TB reactors are found at a skin test. The number of herd tests needed and use of the interferon-gamma blood test depends on which TB risk area the herd is located in, and the results of skin testing and post mortem inspection for any reactors found. To check which TB risk area your herd is located in, take a look at our interactive risk map.
TB Breakdown
(Reactors found at skin test)
Isolation of reactors
Movement restrictions imposed
Reactor cattle removed & slaughtered
Cleaning and disinfection of isolation areas
Short interval skin testing (SIT) at 60 day intervals after reactor removal
Supplementary tests such as the interferon-gamma blood test may also be used
TB free status restored
Once the required skin testing (and any other supplementary tests) are completed with negative results
Slaughterhouse cases
For slaughterhouses cases, the process is slightly different as shown in the flow diagram.
Movement restrictions
If TB is suspected or confirmed in a cattle herd, movement restrictions are automatically immediately applied to the whole herd. This is an important control measure to contain disease on the holding and prevent it spreading to other holdings.
A TB181 information note is handed to the owner/keeper of the cattle at the time of the TB test which explains the restrictions
These restrictions prevent movement of bovine animals on or off the holding, except under a licence issued by the Animal & Plant Health Agency (APHA)
A TB02 notice may also be posted to you when movement restrictions are applied to the herd. This is a legal document which explains the conditions of the restrictions and it’s important that you read it carefully
Milk restrictions
Milk restrictions are also applied immediately if TB is suspected or confirmed in a cattle herd.
- You must tell your milk buyer as soon as milk restrictions are applied
- Holdings registered to sell raw (unpasteurised) milk for direct human consumption must stop sales
- Milk fed from cows in a herd under movement restrictions must not be used for human consumption unless it is heat treated. This has important implications for producers of raw milk and milk products
- Holdings that use raw milk as an ingredient to make milk products (e.g. cream, cheese) must heat treat the milk before use
- Milk from inconclusive reactors (IR) may still go for human consumption provided that it is heat treated before sale
- Milk from TB reactors can be collected in the slurry system, but subsequent spreading to land must be in accordance with the registered Waste Management Licence Exemption. To register, please contact the Environment Agency.
- Milk from TB reactors must not be used for human consumption, even if heat treated, and must be withheld from the bulk tank
- It is recommended that milk from TB reactors is not fed to calves. If fed then it must be heat treated and only fed to animals on the same holding. For more information about the Animal By Products regulations relating to the feeding and disposal of milk, see the guidance on GOV.UK.
Classification of TB breakdowns
TB breakdowns are classified by APHA for operational reasons, to manage the breakdown effectively and ensure that all appropriate disease control activities are carried out. There are two broad categories, and these differ for England, Scotland and Wales.
England
Officially TB free (OTF) herd status is suspended (OTFS) when one or more skin test reactors or interferon-gamma positive animals are detected in a herd, but no lesions typical of TB are found at post mortem inspection, and the culture results are negative for the bovine TB bacterium (M. bovis), or pending. APHA may also apply movement restrictions to temporarily suspend the OTF status of certain herds that are not experiencing a TB breakdown. This will happen automatically for instance when:
- Food Standards Agency inspectors detect one or more slaughterhouse cases of TB originating in the herd and the polymerase chain reaction (PCR) test results for those animals are awaited; or
- TB testing becomes overdue in a herd; or
- one or more inconclusive reactors to the skin test (without reactors) are reported in a herd that had sustained a TB breakdown leading to the withdrawal of OTF herd status (see below) in the previous three years.
OTF herd status is withdrawn (OTFW) if any of the following apply:
- one or more skin test reactors or interferon-gamma positive animals are detected with typical lesions of TB at post mortem inspection
- there is a positive culture result for M. bovis during a TB breakdown
- the herd has one or more slaughterhouse cases of TB with a PCR test (or if necessary) culture result positive for M. bovis
All herds experiencing a new TB breakdown in the High Risk and Edge Areas of England (and certain herds in the Low Risk Area), must undergo a minimum of two successive skin herd tests at severe interpretation with negative results before they can regain OTF status, irrespective of post mortem and culture results. The readings of the disclosing skin test are also reinterpreted at severe.
The main difference between OTFS and OTFW breakdown herds is that the latter can qualify for supplementary interferon-gamma blood testing, and trigger source and spread tracings.