Deer and Bovine TB in the UK: What’s Happening?

Deer and TB in the UK: What’s Happening?

A closer look at TB in deer and its implications for British wildlife and agriculture.

Tuberculosis (TB), specifically bovine TB (bTb) caused by the bacterium Mycobacterium bovis, is an increasing concern in deer populations in the UK , and it’s part of the broader TB problem that affects livestock, wildlife and disease control efforts. bTB is a growing concern for both farmers and wildlife managers across the UK. While much of the focus remains on cattle and badgers, wild deer have become increasingly relevant to the TB conversation. Here’s what you need to know about the current situation.

Deer Can Be Infected and infectious with TB

Wild (and farmed) deer can contract M. bovis, the bacteria responsible for bovine TB. These animals are susceptible to infection, often developing lesions and carrying the disease, particularly in areas where they come into close contact with infected cattle or other wildlife. Notably, regions with high densities of both deer and cattle tend to report more cases of TB among deer. Herding deer such as red, fallow and sika tend to be the species that endemic TB is found more so where their populations are high. Other species and where there are lower populations can see sporadic cases of TB, but they tend to not be a major concern outside of their population. 

Deer as Spill-Over Hosts

In most of the UK, deer do not maintain TB independently. Instead, they typically contract it from cattle or infected wildlife reservoirs. This classification as “spill-over hosts” means:

• Deer can carry and spread TB when circumstances encourage close interactions.

• They generally do not sustain the disease long-term in the population beyond specific local hotspots with intense infection pressure.

Transmission Risks Where Wildlife and Livestock Mix

Deer regularly share grazing areas, water sources and feeding spots with cattle and other farm animals. In these shared environments, TB bacteria may be transferred more likely- through respiratory droplets, less likely but not excluding, contaminated faeces or surfaces, raising the risk of cross-species transmission. This interface is a key focus for those working to control TB in both wildlife and livestock.

Regional Differences in Deer-Cattle Interactions

The nature and frequency of deer-cattle interactions can vary considerably across the UK, depending on local wildlife populations, farming practices and landscape features. Understanding these local dynamics is crucial for effective TB management and for protecting both agricultural livelihoods and native wildlife.

For more updates and practical advice on managing deer effectively visit our website.

How TB in Deer Is Monitored

• Unlike cattle, wild deer are not routinely tested. Surveillance is mostly passive and risk-based.

• Post-mortem surveillance: Deer shot during recreational stalking or population control are inspected. If suspect lesions are found, tissue samples are sent to government labs for testing for Mycobacterium bovis.

• This work is coordinated by the Animal and Plant Health Agency (APHA).

• In high-risk areas (e.g., South West England), APHA may increase sampling of culled deer, conduct focused research and monitor known TB “hotspots”.

Correctly identifying and reporting suspect lesions

TB is a notifiable disease, and it is therefore a legal requirement to be reporting suspect lesions to APHA.  Not only is this a legal requirement it is also important for data collection and the understanding of the TB risk. This factsheet has useful information on how and where to look for TB lesions in deer and how to report. TB in Wild Deer. To report any suspect cases please call APHA on 03000 200301. 

It is also important to ensure that even if lesions are not found or identified that any gralloch is not left out and is correctly disposed of. This is a potential and known risk to transmission of disease. TB when in its early stages of infection, lesions can be microscopic but still hugely infectious. Leaving unwanted parts of the deer in the environment is a potential transmission route. Other mammals and most importantly, badgers, may feed from this and contract the disease. Badgers are known as super spreaders of the disease and when infected are known to shed large amounts of the bacterium from both respiratory and excretory passages. Even if the deer has itself not been shedding the disease it has potential to pass to other mammals when dead and consumed.  

Why This Matters

• Disease spread: If infected deer frequent farmland, they could potentially contribute to TB transmission to cattle herds, complicating disease control efforts on farms.

• Disease management: There’s no routine, systematic TB testing programme in wild deer, so surveillance largely depends on opportunistic findings (e.g., during carcass inspections).

• Control challenges: Because deer can roam widely and freely, controlling TB in deer populations is far more difficult than in managed livestock.

Current Understanding and Research

Ongoing research—including studies on Exmoor—suggests the rate of TB infection in wild deer can sometimes be higher than previously thought and correlates with nearby cattle TB incidence, suggesting cross-species transmission dynamics still need investigation. However, this is quite specific to that area and the unique grazing patterns of the deer on Exmoor. Other studies where deer were thought to be a concern for TB, evidence proved that there were little to no cases of transmission. Deer may or may not be a risk however their ever-increasing population is a concern and as they do have the potential to transmit disease to cattle in one form or another, they should not be overlooked, and management is recommended to be put in place to reduce their risk. 

Farmed Deer

• Farmed deer are treated more like livestock: they can be subject to TB movement restrictions and herd testing if TB is suspected or confirmed.

  
  

How TB in Deer Is Managed

• There is no national deer TB eradication programme, but management focuses on risk reduction.

• Population management: Regulated deer culling helps control density, lowering transmission risk. Managed by landowners and deer managers under UK wildlife law.

• Farm biosecurity: Farmers in high-risk areas are encouraged to avoid leaving supplementary feed accessible to deer, fence off silage clamps and feed stores, and reduce shared access to water troughs.

• Wider bTB control strategy: Deer management is part of the broader bovine TB strategy led by the Department for Environment, Food & Rural Affairs (Defra), which includes cattle testing, movement restrictions, slaughter of infected cattle, and badger control or vaccination.

• Deer are considered a secondary wildlife component, unlike badgers, which are considered a primary wildlife reservoir in England.

The Ongoing Debate

• There’s ongoing scientific and policy debate about whether deer can become a self-sustaining reservoir in some local areas, how significant deer-to-cattle transmission really is, and whether stronger deer controls are necessary in hotspot regions.

• Most evidence still suggests deer are primarily spillover hosts, but local dynamics can vary.

Update

Defra have updated their deer policies, noting that we should expect more night-shooting and closed-season licences on male deer to be issued to help manage the deer population Deer impacts policy statement: managing the impacts of wild deer in England - GOV.UK