Assessment of Skin and Mucosa at the Equine Oral Commissures to Assess Pathology from Bit Wear: The Oral Commissure Assessment Protocol (OCA) for Analysis and Categorisation of Oral Commissures.
Authors: Uldahl Mette, Bundgaard Louise, Dahl Jan, Clayton Hilary Mary
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Researchers photographed and systematically assessed the oral commissures (lip corners) of 206 horses undergoing routine dental examination, developing a standardised Oral Commissure Assessment (OCA) protocol to document pigmentation changes, scarring, erosions, and bruising in this area. Pigment abnormalities—potentially indicative of chronic irritation from bit contact—were significantly more common in horses undertaking higher-level training and in light-coloured animals, though surprisingly showed no correlation with current bit use or specific disciplines; scarring followed a similar pattern associated with competition level. Acute lesions were rare across the cohort (only five ulcers and two contusions/erosions observed; no bleeding), suggesting that whilst chronic tissue changes accumulate with training intensity, catastrophic commissure damage remains uncommon in veterinary caseloads. The OCA protocol itself represents the key practical contribution here, offering equine professionals a detailed, reproducible framework for distinguishing between natural anatomical variation and genuine pathological changes—essential information when investigating bit-related concerns or establishing baseline commissure health. For practitioners, this work underscores that pigmentation changes and scarring in the oral commissures may reflect cumulative training load rather than acute tack fit issues, and provides a systematic method for monitoring this often-overlooked area during preventative examinations.
Read the full abstract on PubMed
Practical Takeaways
- •The OCA protocol enables standardized assessment and documentation of oral commissure lesions during routine dental examinations, improving clinical record-keeping and research comparability
- •Light-coloured horses and those in higher-level training warrant closer monitoring of oral tissue health, though lesion presence is not directly linked to current bit type or discipline
- •Severe acute lesions (contusions, erosions, ulcers) are uncommon in horses presenting for routine care, suggesting that chronic pigmentation changes and scarring may be more clinically significant than acute trauma
Key Findings
- •Pathological pigment changes occurred more frequently in horses with higher training levels (p = 0.04) and light-coloured horses (p = 0.0004)
- •Scars at oral commissures occurred more frequently in horses competing at higher levels
- •No association found between lesion presence and current bit use or riding discipline (p = 0.20)
- •Severe lesions were rare: only 2 horses with contusions/erosions, 5 with ulcers, and none with bleeding