2023 report

updated July 2025

Introduction

In 2023 the Defined Daily Dose Veterinary per year of antibiotics for horses was 1.22. This is a 19% decline of 2021. The use of Highest Priority Critically Important Antibiotics also declined, by 39% to 0.067 DDDVet/yr (0.02 later generation cephalosporins and 0.05 f luoroquinolones). We do not have results from 2022, and the results are from similar but not the same practices as 2021, so they are not completely comparable. Nevertheless a reduction in consumption is encouraging. Perhaps this project is already bearing fruit - if you can’t measure it, you can’t manage it!

Results

These results are from 32 practices which have treated 141,638 horses. The British Equestrian Trade Association survey 2023 estimated that there were 726,000 horses in the UK, thus the data may represent 20% of the UK population.

Potentiated sulphonamides and tetracylines were the commonest antibiotics used, at 0.53 and 0.49 DDDVet/yr respectively. Aminoglycosides were also represented, at 0.06 DDVet/yr and penicillins also at 0.06. Other antibiotics included first and second generation cephalosporins (cefazolin), macrolides, nitroimidazoles (metronidzole), chlorahamphenicol and the ansamycin rifampicin. All antibiotics other than potentiated sulphonamides, tetracyclines and HPCIA’s amounted to 0.14 DDDVet/yr.

This project is ongoing and dynamic. We encourage all practices to submit data, both for 2023 and we are now collecting for 2024. We will need the total mg used for the major antibiotic classes, the total number of horses treated (with or without antibiotics). If the average weight of these horses is available that is ideal. Instructional videos on how to obtain this data for Eclipse and for VetIT are available below.

Commentary

The Defined Daily Dose Veterinary / year refers to the number of days per year which the average horse has received a dose of antibiotics. So if a practice only treated one horse, and it had five days of oral potentiated sulphonamides, the result is 5. If the practice treated that horse and vaccinated four others (so five horses in total) the DDDVet/yr would be 1 (one horse has five days antibiotics and four have none so the average horse got one day that year). Further if you vaccinated another four horses (8 in total) and treated one with ten days of ceftiofur, the DDD would be 1.5 (5 potentiated sulphonamides + 10 ceftiofur / 10 horses). Thus it is independent of the mg of antibiotics used, which would be higher in the potentiated sulphonamides and four vaccines case (say 30000mg x 5 days / 500kg * 5 horses = 60mg/kg) while the ceftiofur and potentiated sulphonamides example might be lower at 32.8 mg/kg (30000 potentiated sulphonamides x 5 days + 1400mg ceftiofur x 10 days / 500kg x 10 horses = 32.8 mg/kg). In essence using mg/kg, the overall figure would be made better despite using more reserved antibiotics. Hence the preference for DDDVet/yr.