Efficacy and effects of various anti-crib devices on behaviour and physiology of crib-biting horses.
Authors: Albright J D, Witte T H, Rohrbach B W, Reed A, Houpt K A
Journal: Equine veterinary journal
Summary
# Editorial Summary: Anti-Crib Device Efficacy in Established Crib-Biters Crib-biting remains one of the most prevalent oral stereotypies in horses, yet empirical evidence supporting the various interventions available to practitioners has been limited. Albright and colleagues conducted two randomised crossover trials to evaluate how well anti-crib collars, muzzles, and surgically implanted gingival rings actually prevent the behaviour whilst simultaneously monitoring physiological stress markers and potential compensatory behaviours. Their first experiment involved eight horses wearing each of three non-surgical devices for consecutive seven-day periods, whilst the second tracked six horses before and after gingival ring implantation; crib-biting frequency and plasma cortisol were measured throughout both studies. All three non-surgical devices proved significantly effective at reducing crib-biting with no meaningful differences between them, and critically, the researchers found no evidence of post-inhibitory rebound or elevated cortisol levels upon device removal—contrary to concerns that suppression might increase stress. However, gingival rings provided only temporary relief before horses adapted to them, and the surgical procedure itself induced a significant cortisol spike, suggesting implantation was painful. These findings underscore that whilst mechanical devices work in the short term, they represent symptomatic management rather than treatment of the underlying problem; practitioners should therefore emphasise concurrent improvements to management, turnout, and feeding practices alongside any device use, and counsel owners that no mechanical solution addresses the fundamental motivations driving stereotypic behaviour.
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Practical Takeaways
- •Anti-crib collars and muzzles are equally effective management tools for established crib-biters; choice can be based on horse comfort and management practicality rather than efficacy differences.
- •Surgical gingival ring implantation is not recommended as a long-term solution due to temporary effectiveness and probable pain to the horse; focus instead on preventing crib-biting through improved husbandry.
- •Use of mechanical devices does not cause rebound stereotypic behavior when removed, supporting their safe use as part of a management strategy while underlying environmental causes are addressed.
Key Findings
- •All tested devices (2 anti-crib collars, muzzle, and gingival rings) significantly reduced crib-biting behavior compared to control periods.
- •No significant differences in crib-bite reduction were found among the three device types in the collar/muzzle experiment.
- •Gingival rings were only temporarily effective and surgery caused elevated cortisol on the day of implantation, suggesting pain.
- •No post-inhibitory rebound effect was observed when devices were removed, indicating devices do not increase stereotypic behavior subsequently.