Presence of Antimicrobials in Postrace Samples in Japanese Thoroughbred Racing.

The study investigates the presence of antimicrobials in 100 postrace horse urine samples collected from ten Japanese racecourses using ultra performance liquid chromatography-tandem mass spectrometry. Among the 21 targeted antimicrobials, seven were detected, with an emphasis on the potential anti-inflammatory effects of oxytetracycline, signalling a need for regulatory measures and continued research.

Background

• Antimicrobials are medicines used to prevent and treat bacterial infections in humans, animals, and plants.
• Recently, research has found that some types of antimicrobials also have anti-inflammatory effects which is a concern for authorities in horse racing as it can potentially be seen as a form of doping to enhance performance.
• The use of antimicrobials in veterinarians has been questioned since the introduction of the ‘One Health’ concept which advocates for the integration of human, animal, and environmental health for a holistic understanding of health risks and diseases.
• There is a need for a regulatory framework for the use of antimicrobials in horse racing to ensure horse welfare and fair play.

Methodology

• The team analyzed 100 postrace urinary samples from horses collected from 10 different Japanese racecourses.
• They targeted 21 different antimicrobials and used a technique called ultra performance liquid chromatography-tandem mass spectrometry to detect them.

Results

• Seven of the 21 targeted antimicrobials were detected in the samples. These include ceftiofur, cefalotin, cefalotin metabolite, dihydrostreptomycin, gentamicin, kanamycin, and oxytetracycline.
• The study only found limited instances of antimicrobials that are critically important for resistance in human medicine, with only one sample showing evidence of such a substance.
• Oxytetracycline, which is known to have anti-inflammatory effects, was found in three samples.

Implications

• The detection of antimicrobials suggests a possible misuse in horse racing either for their antibacterial effects, or possibly for their anti-inflammatory benefits.
• The presence of oxytetracycline in samples suggests the need for better regulations to control doping in horse racing.
• Further studies are required to identify the pharmacologically relevant concentration of antimicrobials with such properties in horse racing.