Why is it important to monitor the use of antibiotics in our horses?

A study undertaken to investigate the use of antimicrobials in horses shows why it is so important for our vets to test before prescribing.

Antimicrobial resistance poses a significant and increasing threat to human and animal health. Quite simply, once antimicrobial resistance develops, it can result in treatment failure in veterinary patients and, due to the proximity in which animals and their owners often live, the potential transfer of resistant bacteria to people.

Concerns have been raised regarding the possible overuse of antimicrobials in veterinary species, which is known to contribute to the development of resistant bacterial populations so, the RVC’s VetCompass programme set up a study to investigate. The team used anonymised electronic health record data from 64,322 horses, ponies and donkeys in the year 2018, supplied by 39 veterinary practices participating in the programme. The team analysed both the prescription data and clinical notes documented within these records.

The findings highlighted that in 2018, approximately 20 per cent of equines attended by the participating veterinary practices were prescribed an antimicrobial licensed for systemic administration and, nearly nine per cent of those equines received a Category B antimicrobial – an antibiotic that is of highest priority critical importance for human medicine and, should be used cautiously in animals to mitigate the risk to public health.

Bacteriological culture and sensitivity testing to determine the most appropriate antimicrobial to administer – or indeed if one was indicated was not always undertaken, despite its importance in protecting against antimicrobial resistance. Fewer than one in five antimicrobial courses that included a Category B antimicrobial were supported by culture and sensitivity testing.

It was found thatt the highest usage groups of Category B antimicrobials were equines under one year old, Thoroughbreds and racehorses, with the most common disorders treated with antimicrobials were urogenital (urinary and genital tracts), integumentary (skin and gland organs) and respiratory (airways, lungs and blood vessels) conditions.

By reporting on antimicrobial usage across a large number of veterinary practices, the study hopes to encourage others to consider and benchmark their own usage, and promote more responsible antimicrobial prescription, especially of those deemed of the highest priority critical importance for human health.