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veterinary
2021
Expert Opinion

Bit-Related Lesions in Event Horses After a Cross-Country Test.

Authors: Tuomola Kati, Mäki-Kihniä Nina, Valros Anna, Mykkänen Anna, Kujala-Wirth Minna

Journal: Frontiers in veterinary science

Summary

# Editorial Summary: Bit-Related Lesions in Event Horses After Cross-Country Finnish researchers examined 208 event horses immediately following cross-country competition to establish the prevalence and risk factors for oral lesions in the bit contact area. Over half the cohort (52%) presented with acute lesions post-cross-country, with lesion severity distributed across mild (22%), moderate (26%), and severe (4%) categories, predominantly affecting the inner lip commissures. Bit diameter emerged as a significant risk factor, with both thin (10–13 mm) and thick (18–22 mm) diameters conferring 3.4–3.5 times greater odds of moderate-to-severe lesions compared to middle-sized bits (14–17 mm), whilst unjointed bits showed considerably higher rates of bar lesions (40%) than single- or double-jointed alternatives (5–10%). Breed and sex characteristics also influenced lesion risk: mares demonstrated twice the odds of moderate-to-severe lesions relative to geldings, and warmbloods and coldbloods showed higher susceptibility than ponies. These findings suggest that practitioners should consider bit selection—particularly favouring middle-diameter, jointed designs—as a modifiable welfare factor, and that routine oral cavity assessment following cross-country phases could identify welfare concerns and inform equipment adjustments for individual horses.

Read the full abstract on PubMed

Practical Takeaways

  • Bit diameter matters: aim for 14-17 mm bits to minimize oral trauma; both very thin and very thick bits significantly increase lesion risk
  • Consider bit joint design: double-jointed (especially formed) or single-jointed bits cause fewer bar lesions than unjointed designs
  • Monitor mares more closely for bit-related lesions as they show higher susceptibility than geldings; implement routine oral inspections post-competition as a welfare best practice

Key Findings

  • 52% (109/208) of event horses had acute oral lesions after cross-country competition, with 4% classified as severe
  • Thin (10-13 mm) and thick (18-22 mm) bits carried 3.4-3.5× higher risk of moderate/severe lesions compared to middle-sized (14-17 mm) bits (P=0.003)
  • Mares had 2.2× higher risk of moderate/severe lesions than geldings (P=0.03)
  • Unjointed bits showed 40% bar lesion prevalence compared to 5-10% for jointed bit types (P=0.002)

Conditions Studied

bit-related oral lesionsinner lip commissure lesionsbar lesions