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Veterinary practices and a bovine TB future

29 July 2019, at 9:00am

Will the vet’s role evolve in an updated picture of bovine TB in the UK?

Earlier this year, veterinary surgeons attending an evening meeting in Devon to discuss bovine TB were asked by the speaker to indicate their confidence that the current initiatives were leading to disease eradication. A forest of hands indicated that the veterinary surgeons were dissatisfied by the current levels of disease. The speaker clearly had strong views and it may be that the audience was being manipulated; however, at the Official Veterinarian Conference in September and the British Cattle Veterinary Association Congress in October, there will be in-depth analysis and discussion about the current and future tools, initiatives and approaches to combat the disease.

The veterinary surgeons who raised their hands at the meeting were reacting to the disease occurrences within their clients’ herds. Individual veterinary practice data is not generally available, but county and country statistics have been published, so individual veterinary surgeons can compare their experience to the general picture.

The current bTB situation in the UK

The latest situation for Devon is that there are 4,697 herds, and 1,364 herds (29 percent) were bTB restricted during the 12 months to the end of February 2019. There is a great range of data available but in order to gauge progress with disease eradication, the 688 new herd incidents identified may be relevant. Five years earlier, there were some 130 more herds in the county and 817 new incidents. Devon has had the highest number of infected herds for many years; the data for neighbouring counties is shown in Table 1.

If the county data reflects individual veterinary practice incidence then around a quarter of cattle clients in the south west will have had cause to be dissatisfied with bovine TB in the past 12 months. Around half of those under restriction are because the herd has been detected with a new bTB incident. Although the new incidents are lower than five years earlier, there has not been a major fall in recorded new bTB failures.

It seems reasonable to consider that where an effective disease control programme has been implemented, the first impact would be on new incidents. The herds were considered disease free and now they are not. The information currently being collected from those herds should be very valuable in identifying whether there are common disease breakdown factors. Data are available for all regions and counties online (for a summary, see Table 2; Defra, 2019). Interrogate the regional summary online and the specific dataset is available for each county with high, edge and low risk groupings.

To appreciate the scale of disease nationally, there are 48,523 herds recorded in England, 11,852 in Wales and 13,248 in Scotland. Some 10 million cattle were tested in the year to the end of February 2019 (England: 7.7 million, Wales: 2.1 million and Scotland: 269,000). The numbers of herds under movement restriction are: 4,216 (9 percent) in England; 953 (8 percent) in Wales; and 136 (1 percent) in Scotland.

In terms of farmer and veterinary surgeon dissatisfaction, the local situation in the higher incidence counties is masked if the national figures dominate general understanding. Individual veterinary practice incidence or parish incidence would provide a more accurate picture. There is considerable concern about cattle TB beyond farmers, vets and officials, and more local information would be of value.

TABLE 1 Data from south-western UK counties show the number of herds, proportion that are TB restricted and the number of new herd incidents in 2018 compared to 2014 (adapted from Defra, 2019)
TABLE 1 Data from south-western UK counties show the number of herds, proportion that are TB restricted and the number of new herd incidents in 2018 compared to 2014 (adapted from Defra, 2019)

The numbers of cattle slaughtered have increased over the past five years. The comparable data is in the years to the end of December, and in 2018, the numbers of cattle slaughtered were:

  • 32,925 in England (compared to 26,413 in 2014)
  • 11,233 in Wales (6,371 in 2014)
  • 498 in Scotland (240 in 2014)

The new herd incidents are recorded as:

  • England: 3,612 (3,804 in 2014)
  • Wales: 746 (857 in 2014)
  • Scotland: 498 (240 in 2014)

It is widely reported that the testing intensity schedules for Wales have been improved and the number of tests has risen from 1.9 million to 2.1 million over five years with the number of cattle slaughtered increasing from 6,371 to 11,233.

TABLE 2 Data from 12 months to the end of February 2019 for all regions in England (adapted from Defra, 2019)
TABLE 2 Data from 12 months to the end of February 2019 for all regions in England (adapted from Defra, 2019)

Key developments under discussion

One of the aspects under discussion at the forthcoming conferences is whether alternatives to the skin test are expected to be applied and how this impacts on the detection of disease. There are many issues, but it is the early detection of disease in herds that are currently considered free of disease that is exciting some veterinary specialists; if this can be detected from routine milk samples then the eradication programme would enter a new phase of hope. The recent study of cattle chains has indicated that dairy herds are a major source of cattle for other farms and the inference is that if bTB could be controlled in dairy herds then national eradication may be a major step closer.

Two practical considerations that were discussed at the Devon meeting are working within the current test and control programmes, but there was considerable concern expressed that test and cull is not sufficient to control the disease. The first concerns neighbours. It is believed that a major risk to a cattle herd is the disease status of neighbouring herds. For veterinary practices, this is a difficult aspect because within a local area, there are likely to be different practices servicing the needs of the herds. However, the use of specialists is well founded where a veterinary surgeon from outside the practice is invited to visit a client and implement a disease control programme. Veterinary cooperation can be achieved if clients are convinced of the benefit.

A major step change discussed was to consider contamination from cow to cow based on the knowledge gained from the Johne’s control initiative. There is likely to be more detail available about the steps needed but cleanliness and the transfer of mycobacteria from gut to dung to another cow and reducing the build-up of the organism within housing and elsewhere may also have wider benefits. Organism control in bedding, walkways and water troughs requires considerable enthusiasm from the farm staff. Step forward the vet as motivator.

Veterinary surgeons are encouraged to consider the aspects of bovine TB control that are effective within their practice and to engage with any new tools and ideas that are discussed. Detailed work has been signified going for-ward and it seems unacceptable to settle for having to live with current levels of bovine TB.