Research and analysis

UK-VARSS 2024 Highlights

Published 18 November 2025

1. Antibiotic use and resistance

A decade of bringing together antibiotic use and resistance data.

This year’s UK-VARSS report marks 10 years of bringing together data on antibiotic sales, usage and resistance. This allows us to show long-term trends and demonstrate how reducing antibiotic use has been followed by a reduction in antimicrobial resistance (AMR) at a national level.

Infographic to show sales of antibiotics in food-producing animals in mg/kg from 2014-2024:

• 2014 - 36.0
• 2015 – 32.5
• 2016 – 22.9
• 2017 – 19.3
• 2018 – 17.9
• 2019 – 18.7
• 2020 – 18.7
• 2021 – 17.4
• 2022 – 15.7
• 2023 – 15.9
• 2024 – 15.6

Infographic to show sales of HP-CIAs in mg/kg, in food-producing animals 2014-2024:

• 2014 – 0.38
• 2015 – 0.36
• 2016 – 0.22
• 2017 – 0.15
• 2018 – 0.12
• 2019 – 0.09
• 2020 – 0.08
• 2021 – 0.06
• 2022 – 0.06
• 2023 – 0.06
• 2024 – 0.06

Infographic to show percentage of fully susceptible E.coli isolates 2014-2024 – Full susceptibility means there was no resistance to the antibiotics tested:

• 2014-2015: 17.9%
• 2015-2016: 19.7%
• 2016-2017: 23.2%
• 2017-2018: 33.7%
• 2018-2019: 32.7%
• 2019-2020: 36.7%
• 2020-2021: 38.7%
• 2021-2022: 40.2%
• 2022-2023: 43.2%
• 2023-2024: 35.8%

Infographic to show percentage of multi-drug resistant E.coli isolates 2014-2024. Multi-drug resistance means resistance to three or more classes of antibiotics:

• 2014-2015: 56.7%
• 2015-2016: 49.2%
• 2016-2017: 45.1%
• 2017-2018: 36.3%
• 2018-2019: 36.1%
• 2019-2020: 31.8%
• 2020-2021: 30.9%
• 2021-2022: 31.1%
• 2022-2023: 26.8%
• 2023-2024: 26.6%

2. Antibiotic sales

2.1 Sales for food-producing animals (mg/kg)

Sales of veterinary antibiotics for use in food-producing animals, adjusted for animal population, were 15.6 mg/kg; this represents a 2% (0.3 mg/kg) change since 2023 and an overall 57% (20.5 mg/kg) decrease since 2014.

Infographic showing the sales in mg/kg between 2014 and 2024.

• 2014 – 36.0
• 2015 – 32.5
• 2016 – 22.9
• 2017 – 19.3
• 2018 – 17.9
• 2019 – 18.7
• 2020 – 18.7
• 2021 – 17.4
• 2022 – 15.7
• 2023 – 15.9
• 2024 – 15.6

Sales of Highest Priority Important Antibiotics (HP-CIAs) in food-producing animals remain at very low levels at 0.06 mg/kg in 2024 and account for 0.4% of total sales.

Infographic showing the classes of HP-CIAs and total sales for 2014, 2023 and 2024:

• Total HP-CIAs: In 2014 0.38 mg/kg were sold, in 2023 0.06 mg/kg were sold and in 2024 0.06 mg/kg were sold which represents an 84% decrease since 2014.
• Total fluoroquinolones: In 2014 0.20 mg/kg were sold, in 2023 0.05 mg/kg were sold and in 2024 0.05 mg/kg were sold which represents a 74% decrease since 2014.
• Total 3rd and 4th generation cephalosporins: In 2014 0.11 mg/kg were sold, in 2023 0.01 mg/kg were sold and in 2024 0.01 mg/kg were sold which represents a 93% decrease since 2014.
• Colistin: In 2014 0.07 mg/kg were sold, in 2023 0.00 mg/kg were sold and in 2024 0.00 mg/kg were sold which represents a 100% decrease since 2014.

2.2 New metric

A new harmonised mg/kg metric for all animals has been developed for analysing sales data. This uses different animal categories and weights. This metric has been used by the EU when publishing their 2023 sales in 2025. We have introduced this new metric as we recognise the value of harmonised regional surveillance. The 2024 UK sales using this metric is 15.6 mg/kg.

2.3 Sales of antibiotics for all animals in tonnes

In 2024 the total quantity of antibiotic active ingredient sold in the UK was 194 tonnes, the lowest sales to date.

Infographic showing the total sales for all animals in tonnes:

• 2014 – 452
• 2015 – 411
• 2016 – 299
• 2017 – 256
• 2018 – 238
• 2019 – 243
• 2020 – 242
• 2021 – 228
• 2022 – 205
• 2023 – 200
• 2024 – 194 tonnes which is a reduction of 57% since 2014.

Over 50% of all antibiotics sold were either tetracyclines (31%) or penicillins (26%).

2.4 Sales of HP-CIAs for all animals in tonnes

Sales of HP-CIAs, not adjusted for animal population size, for 2024 was 0.79 tonnes, representing a decrease of 3% (0.03 tonnes) since 2023 and an 83% decrease (4 tonnes) since 2014. Sales of HP-CIAs continue to represent a small proportion (<0.5%) of total veterinary antibiotic sales in tonnes.

3. Antibiotic usage

Antibiotic usage refers to the amount of antibiotics prescribed and/or administered per sector. The data have been collected and provided to the VMD by the animal industry on a voluntary basis.

3.1 Antibiotic usage by food-producing animal species

Infographic showing the antibiotic usage, in tonnes, by food-producing animal species for 2024, the change since 2023 and the percentage change since the date of first publication and annual trends since data was first published by each sector.

• Pigs: 63.0 which is equivalent to 50.0 mg/kg. This is a 0.84 mg/kg increase since 2023 and represents an overall decrease of 69% since data of first publication in 2015.
  • 2015 - 159.9
  • 2016 - 105.8
  • 2017 - 78.6
  • 2018 - 63.9
  • 2019 - 64.2
  • 2020 - 61.0
  • 2021 - 50.7
  • 2022 - 41.5
  • 2023 - 49.2
  • 2024 - 50.0
• Broilers: 11.2 which is equivalent to 4.7 mg/kg. This is a 0.92 mg/kg decrease since 2023 and represents an overall decrease of 77% since date of first publication in 2014.
  • 2014 - 20.3
  • 2015 - 11.4
  • 2016 - 7.1
  • 2017 - 4.1
  • 2018 - 5.2
  • 2019 - 7.3
  • 2020 - 6.8
  • 2021 - 5.7
  • 2022 - 5.9
  • 2023 - 5.6
  • 2024 - 4.7
• Gamebirds: 10.3 which is a 0.47 tonne increase since 2023 and represents an overall decrease of 48% since date of first publication in 2016.
  • 2016 - 20.0
  • 2017 - 12.6
  • 2018 - 9.2
  • 2019 - 10.0
  • 2020 - 5.7
  • 2021 - 8.9
  • 2022 - 6.7
  • 2023 - 9.9
  • 2024 - 10.3
• Laying hens: 2.0 which reported at 0.28% bird days. This is a 0.06% bird days increase since 2023 and represents a 58% decrease since date of first publication in 2016.
  • 2016 - 0.67 %
  • 2017 - 0.57 %
  • 2018 - 0.55 %
  • 2019 - 0.68 %
  • 2020 - 0.47 %
  • 2021 - 0.33 %
  • 2022 - 0.23 %
  • 2023 - 0.22 %
  • 2024 - 0.28 %
• Turkeys: 2.0 which is equivalent to 19.7 mg/kg. This is a 3.2 mg/kg increase since 2023 and represents an overall decrease of 82% since date of first publication in 2014.
  • 2014 - 108.1
  • 2015 - 98.4
  • 2016 - 42.6
  • 2017 - 22.3
  • 2018 - 23.0
  • 2019 - 20.7
  • 2020 - 12.7
  • 2021 - 21.0
  • 2022 - 17.4
  • 2023 - 16.6
  • 2024 - 19.7
• Salmon: 0.9 which is equivalent to 4.9 mg/kg. This is a 15 mg/kg decrease since 2023 and represents an overall decrease of 70% since date of first publication in 2017.
  • 2017 - 16.1
  • 2018 - 6.7
  • 2019 - 13.5
  • 2020 - 29.3
  • 2021 - 43.1
  • 2022 - 18.6
  • 2023 - 19.9
  • 2024 - 4.9
• Trout: 0.05 which is equivalent to 5.1 mg/kg. This is a 1.8 mg/kg decrease since 2023 and represents an overall decrease of 73% since date of first publication in 2017.
  • 2017 - 19.2
  • 2018 - 13.0
  • 2019 - 9.7
  • 2020 - 13.9
  • 2021 - 9.0
  • 2022 - 44.1
  • 2023 - 6.9
  • 2024 - 5.1
• Ducks: 0.01 which is equivalent to 0.24 mg/kg. This is a 0.08 mg/kg increase since 2023 and represents an overall decrease of 96% since date of first publication in 2017.
  • 2014 - 6.3
  • 2015 - 3.4
  • 2016 - 1.4
  • 2017 - 1.4
  • 2018 - 0.7
  • 2019 - 0.7
  • 2020 - 1.1
  • 2021 - 0.7
  • 2022 - 0.1
  • 2023 - 0.2
  • 2024 - 0.2

3.2 Highest Priority Critically Important Antibiotics by food-producing animal species

Infographic showing the use of HP-CIAs in kg and change since 2022 as well as change since data was first published annual trends since data was first published by each sector:

• Gamebirds: 45.1 kg. This is a 17.5 kg increase since 2023 and represents an overall decrease of 30% since date of first publication in 2016.
  • 2016 – 64.1
  • 2017 – 49.6
  • 2018 – 47.0
  • 2019 - 57.8
  • 2020 – 21.3
  • 2021 – 26.5
  • 2022 – 23.2
  • 2023 – 27.7
  • 2024 – 45.1
• Trout: 14.8 kg which is equivalent to 1.5 mg/kg. This is a 0.03 mg/kg decrease since 2023 and represents an overall decrease of 78% since date of first publication in 2017.
  • 2017 - 6.6
  • 2018 – 5.8
  • 2019 – 2.4
  • 2020 – 4.3
  • 2021 – 3.2
  • 2022 – 2.2
  • 2023 – 1.8
  • 2024 – 1.5
• Pigs: 6.2 kg which is equivalent to 0.005 mg/kg. This is a 0.001 mg/kg increase since 2023 and represents an overall decrease of 99% since date of first publication in 2015.
  • 2015 – 0.56
  • 2016 – 0.15
  • 2017 - 0.06
  • 2018 – 0.04
  • 2019 – 0.02
  • 2020 – 0.03
  • 2021 – 0.02
  • 2022 – 0.007
  • 2023 - 0.004
  • 2024 – 0.005
• Laying hens: 3.0 kg which is equivalent to 0.0007% bird days. This is an increase of 0.0007% bird days since 2023 and represents an overall decrease of 98% since date of first publication in 2016.
  • 2016 - 0.03 %
  • 2017 - 0.00 %
  • 2018 - 0.00 %
  • 2019 - 0.00 %
  • 2020 - 0.00 %
  • 2021 - 0.00 %
  • 2022 - 0.00 %
  • 2023 - 0.00 %
  • 2024 - 0.0007 %
• Meat Poultry: 0.002 kg which is equivalent to 0.0009 mg/kg. This is a 0.001 mg/kg decrease since 2023 and represents an overall decrease of 99.8% since date of first publication in 2014.
  • 2014 - 0.51
  • 2015 - 0.24
  • 2016 - 0.05
  • 2017 - 0.01
  • 2018 - 0.007
  • 2019 - 0.004
  • 2020 - 0.003
  • 2021 - 0.02
  • 2022 - 0.00
  • 2023 - 0.002
  • 2024 - 0.0009

4. Antibiotic resistance – harmonised monitoring

4.1 Key resistance outcome indicators: E. coli

The harmonised monitoring outcome indicators combine results from healthy pigs and poultry at slaughter to give an overall picture of antimicrobial resistance (AMR), and are internationally comparable.

Results show a decrease in fully susceptible E. coli from 43% in 2022/2023 to 36% in 2023/2024. This is the first substantial decrease since harmonised monitoring began in 2014 and is attributable to increased resistance in broilers. The percentage of multi-drug resistant isolates (resistant to three or more antibiotic classes) continues to decrease and remains at the lowest recorded level of 27%.

Infographic showing the proportion of E. coli isolates showing full susceptibility to the panel of antibiotics tested and the percentage of multi-drug resistant isolates:

• 2014/2015, the percentage of E. coli isolates fully susceptible was 17.9%. The percentage of multi-drug resistant isolates was 56.7%.
• 2015/2016, the percentage of E. coli isolates fully susceptible was 19.7%.  The percentage of multi-drug resistant isolates was 49.2%.
• 2016/2017, the percentage of E. coli isolates fully susceptible was 23.2%. The percentage of multi-drug resistant isolates was 45.1%.
• 2017/2018, the percentage of E. coli isolates fully susceptible was 33.7%. The percentage of multi-drug resistant isolates was 36.3%.
• 2018/2019, the percentage of E. coli isolates fully susceptible was 32.7%. The percentage of multi-drug resistant isolates was 36.1%.
• 2019/2020, the proportion of E. coli isolates fully susceptible was 36.7%.  The percentage of multi-drug resistant isolates was 31.8%.
• 2020/2021, the percentage of E. coli isolates fully susceptible was 38.7%.  The percentage of multi-drug resistant isolates was 30.9%.
• 2021/2022, the percentage of E. coli isolates fully susceptible was 40.2%. The percentage of multi-drug resistant isolates was 31.1%.
• 2022/2023, the percentage of E. coli isolates fully susceptible was 43.2. The percentage of multi-drug resistant isolates was 26.8%.
• 2023/2024, the percentage of E. coli isolates fully susceptible was 35.8. The percentage of multi-drug resistant isolates was 26.6%.

4.2 Full susceptibility in Salmonella

In 2024, fully susceptible Salmonella isolated from broilers and laying hens decrease but increased in turkeys.

Infographic showing the percentage of Salmonella isolated from broilers, laying hens and turkeys that are fully susceptible to the panel of antibiotics tested, that is, no resistance was found:

• In laying hens, full susceptibility was 93% in 2014, 85% in 2016, 81% in 2018, 78% in 2020, 92.9% in 2022, 91.4% in 2024.

• In broilers, full susceptibility was 64% in 2014, 67% in 2016, 84% in 2018, 72% in 2020, 78.8% in 2022, 67.9% in 2014.

• In turkeys, full susceptibility was 31% in 2014, 22% in 2016, 20% in 2018, 20.2% in 2022, 38.6% in 2024.

4.3 Resistance in Campylobacter

Resistance to ciprofloxacin on Campylobacter jejuni from broilers and turkeys has increased since 2022 despite minimal use by these sectors.

Infographic showing the percentage of Campylobacter jejuni isolated from broilers and turkeys that resistant to ciprofloxacin

• In broilers, ciprofloxacin resistance was 43.6% in 2014, 40.6% in 2016, 48% in 2018, 59.2% in 2020, 58.9% in 2022, 70% in 2024.
• In turkeys, ciprofloxacin resistance was 35% in 2014, 34.7% in 2016, 31% in 2018, 34.6% in 2020, 25.7% in 2022, 32.1% in 2024.

4.4 Using selective media to detect E. coli

We also perform a more sensitive type of testing using selective media which inhibits the growth of susceptible bacteria but allows bacteria with specific resistances to multiply, making them easier to detect. This tells us the percentage of individual sample containing resistance to the HP-CIAs, even when present in very low numbers.

In 2024, carriage of ESBL-/AmpC- producing E. coli, which are resistant to third and fourth generation cephalosporins and penicillins, increased in broilers and decreased in turkeys.

Infographic showing carriage of ESBL-/AmpC- producing E. coli, which are resistant to third and fourth generation cephalosporins and penicillins

• In broilers, the carriage of ESBL-and or AmpC- producing E. coli which are resistant to third and fourth generation cephalosporins and penicillins was 30.1% in 2016, 10.3% in 2018, 4.6% in 2020, 10.5% in 2022, 14.5% in 2024.
• In turkeys, the carriage of ESBL-and or AmpC- producing E. coli which are resistant to third and fourth generation cephalosporins and penicillins was 4.7% in 2016, 3.8% in 2018, 1.5% in 2020, 8.5% in 2022, 7% in 2024.

Infographic showing carriage of ESBL-/AmpC- producing E. coli, carbapenamase producing E. coli and colistin resistant E. coli in 2024.

• In broilers, carriage of ESBL-/AmpC- producing E. coli was 14.5%, carriage of carbapenamase producing E. coli was 0%, carriage of colistin resistant E. coli was 0%.
• In turkeys, carriage of ESBL-/AmpC- producing E. coli was 7%, carriage of carbapenamase producing E. coli was 0%, carriage of colistin resistant E. coli was 0.4%.

5. Antibiotic resistance- clinical surveillance

Clinical surveillance is a programme of passive is a programme of passive surveillance which evaluates AMR in bacteria isolated from diagnostic samples some of which also have zoonotic potential. As this kind of scanning surveillance is subject to biases and differences in the number of samples, the results are not representative of the UK’s wider animals populations.

5.1 Overview of sampling

6,921 isolates were tested AMR in England and Wales in 2024. The percentage of isolates tested by main animal species were: poultry (30% of isolates), pigs (17%), cattle (9%), and dogs (7.4%).

5.2 Percentage of E. coli with limited treatment options

In 2024, 19% of all clinical E. coli isolated from animals had limited treatment options, meaning they were resistant to four or more individual antibiotics. This has reduced significantly from 40% since 2017.

The percentage of isolates with limited treatment options declines substantially in pigs, cattle and sheep between 2017-2024.

Infographic showing percentage of all isolates tested between 2017 and 2024 which had limited treatment options meaning they were resistant to four or more individual

• In 2017, 39.5%
• In 2018, 34.5%
• In 2019, 31.2%
• In 2020, 27.9%
• In 2021, 29.7%
• In 2022, 24.3%
• In 2023, 18.2%
• In 2024, 19.1%

5.3 Resistance to selected antibiotics in E. coli isolates from pigs 2014-204

In E. coli isolated from pigs in 2024, the highest levels of resistance were detected to the antibiotic classes that are most commonly used in the pig sector: penicillins, trimethoprim, tetracyclines and aminoglycosides.

Resistance of clinical E. coli to antibiotics in the first three classes has reduced since 2014, mirroring reductions in antibiotic use.

Resistance to neomycin has increased significantly from 3.9% in 2014 to 14% in 2024. This aligns with antibiotic use data for aminoglycosides in pigs, which increased from 2 mg/kg in 2015 to 6.8 mg/kg in 2024.

Infographic showing E. coli isolated from pigs resistant to the antibiotics ampicillin, trimethoprim/sulfonamide, tetracycline and neomycin between 2014-2024.

• For ampicillin, resistance in E. coli isolates from pigs was 57.8% in 2014, 56% in 2015, 55% in 2016, 48.8% in 2017, 54.9% in 2018, 60.8% in 2019, 52.7% in 2020, 48.6% in 2021, 49.9% in 2022, 48.8% in 2023, 45.4% in 2024.
• For tetracycline resistance in E. coli isolates from pigs was 78.9% in 2014, 66.5% in 2015, 66.3% in 2016, 62.8% 2017, 61.1% in 2018, 64.2% in 2019, 56.1% in 2020, 55.6% in 2021, 50.3% in 2022, 54.5% in 2023, 51.1% in 2024.
• For trimethoprim/sulfonamide resistance in E. coli isolates from pigs was 56.7% in 2014, 54.4% in 2015, 54.3% in 2016, 45.6% in 2017, 47.5% in 2018, 45.8% in 2019, 42.2% in 2020, 41.7% in 2021, 45.4% in 2022, 37.7% in 2023, 36% in 2024.

6. Background

6.1 How are sales data collected?

In the UK, from 2005 it has been a statutory requirement for pharmaceutical companies to report to the VMD the quantity of antibiotics sold for use in animals. This data does not take into account special imports of veterinary antibiotics not authorised for sale in the UK but authorised elsewhere, and some medicines may not be used in the same year (or at all if the product goes out of date before being used). However, they serve as the best currently available approximation of the quantity of antibiotics administered to animals within the UK.

6.2 How are usage data collected?

Antibiotic usage data, i.e. the amount of antibiotics purchased, prescribed and/or administered, has the potential to provide much more precise estimates of use as it allows antibiotic use to be split by species/ sector and also include antibiotics imported under the special import scheme.

Antibiotic usage data collection systems have been put in place by the British Poultry Council (meat poultry), the British Egg Industry Council (laying hens),the Game Farmers Association and British Veterinary Poultry Association (gamebirds), the electronic Medicines Book (pigs), the British Trout Association (trout), Salmon Scotland (Salmon) and Medicine Hub (ruminants). This data has been voluntarily provided by producers (pigs, poultry and laying hens), feed companies (gamebirds) and veterinary practices (gamebirds and fish).

6.3 What are Critically Important Antibiotics (CIAs)?

HP-CIA refers antibiotics that are vitally important to human medicine and where there is the highest risk of transmission from non-human sources. These are defined by the World Health Organisation (WHO) List of Medically Important Antimicrobials, and include third- and fourth- generation cephalosporins, polymyxins (e.g. colistin) and quinolones/fluoroquinolones. This also aligns with “Category B” in the European Antimicrobial Expert Group report categorisation (AMEG).

6.4 How is antibiotic resistance interpreted?

Antibiotic resistance in bacteria isolated from animals is monitored through two distinct surveillance programmes: harmonised monitoring and clinical surveillance. The harmonised monitoring scheme is a UK-wide programme in which we test bacteria from the gut of healthy pigs and poultry at slaughter, and the National Control Programme for Salmonella, giving us a representative picture of resistance in key livestock species entering the food chain. Clinical surveillance involves the testing of bacteria that have been isolated from clinical samples submitted by farmers and private veterinarians to government laboratories in England and Wales.

Susceptibility testing for harmonised monitoring is performed using broth microdilution to determine minimum inhibitory concentrations (MICs). Resistance is assessed using EUCAST (European Committee on Antimicrobial Susceptibility Testing) epidemiological cut-off values (ECOFFs) where possible. Where no EUCAST values were available, European Food Safety Authority (EFSA) recommended cut-off values were used. Where neither defined values are available, tentative EUCAST ECOFF values were applied. Results interpreted using ECOFFs are reported in full in Supplementary Material 5.

In the 2024 clinical surveillance programme, the majority of the results presented were assessed by disc diffusion techniques, and interpreted using BSAC (British Society for Antimicrobial Chemotherapy) human clinical breakpoints (CBPs) where available. Broth microdilution testing was introduced in UK-VARSS 2020 and continues to be developed and applied to an increasing number of organisms over the last four years. MIC results have been interpreted using veterinary clinical breakpoints from Clinical and Laboratory Standards Institute (CLSI) in the first instance, or Comité de l’Antibiogramme de la Société Française de Microbiologie (CA-SFM) when these are not available; if veterinary clinical breakpoints were not available, human clinical breakpoints were used. Full details of the methods used are available in Supplementary Materials 6.