17 Nov 2025
Study authors hope the results will inform equine clinicians and owners to better treat and manage cases.
Chris Simpson
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Image © Elenathewise / Adobe Stock
A collaborative clinical study undertaken by CVS Group has offered new insights into the causes and treatment of a common equine condition.
The veterinary group has revealed its findings from a two-year study into equine pastern dermatitis (EPD) involving 12 of its equine practices, which ran from 2022 to 2024.
CVS collected samples from 76 cases of horses diagnosed with EPD from around the UK and assessed full blood profiles, conducted bacterial culture analysis of the lesions, skin cytology, PCR analysis for ringworm fungi and microscopy for mites.
Hindlimbs were most affected, accounting for 58 (76.3%) of the cases, with lesions most commonly found in the pastern region.
Clinical signs included erythema, scaling, localised oedema and pruritus.
Mites and dermatophyte (ringworm) involvement were identified in just two and one (2.6% and 1.3%) lesion samples, respectively.
However, 185 bacterial colonies originated from the 76 samples with 40 bacterial species identified.
Streptococcus dysgalactiae was the most prevalent, found in 29 samples (32.8%), followed by Staphylococcus aureus (21 samples/27.6%) and Escherichia coli (13/17.1%).
Fewer than half of cultured organisms (45.9%) demonstrated susceptibility to penicillin, while oxytetracycline resistance was discovered in 35.1% of the colonies and trimethoprim sulphonamide resistance in 20.5%.
Charlotte Sinclair, the group’s equine development lead, said: “Our analysis of 76 cases over two years has highlighted the multifaceted nature of EPD – both in terms of its clinical presentation and severity and its potential aetiologies.
“Our results show several commonly implicated organisms, however further research is required to determine their clinical significance to EPD.”
She added: “The information this study provides on resistance patterns may help to guide antimicrobial use when treating these cases, to help improve antimicrobial stewardship.”
CVS Equine recently announced the launch of a five-point plan to improve antimicrobial stewardship, which included the development of a QI project to reduce antibiotic use in EPD cases.
