Description
Background: The rider's rein aids rely on force transmitted via the reins to the bit and oral structures. Concerns have been raised that two bits may result in an increase in forces applied to the oral structures.Study design: In vivo experimental.
Methods: Thirteen dressage horse/rider combinations (Intermediare-II/Grand-Prix) were recruited and assessed by a veterinarian. Data were collected during straight-line locomotion in collected walk/sitting-trot/canter wearing snaffle (SB) and double bridles (DB). Bridle fit was assessed by two qualified bridle fitters. A Crank noseband was standardised to two-fingers tightness using a taper gauge. Miniature s-beam load cells (range 0–500 N) were fitted to the left/right sides of snaffle, bridoon and curb bits. The total rein force for the SB and DB (curb+bridoon) and individual forces for the snaffle/curb/bridoon bits were analysed using a Wilcoxon signed rank test with significance set at P ≤ 0.05.
Results: Total force for the DB (curb+bridoon) was less than the SB in trot (SB: 53.7 ± 17.6 N, DB: 44.9 ± 18.8 N, p = 0.008). No differences were seen in collected walk (p = 0.55) or canter (p = 0.84). Total force was lower for the curb bit than the bridoon bit in collected walk (bridoon: 20.7 ± 0.9 N, curb: 9.6 ± 4.5 N, p ≤ 0.001), trot (bridoon: 26.4 ± 15.2 N, curb: 19.1 ± 9.6 N, p = 0.02) and canter (bridoon: 39.8 ± 19.5 N, curb: 20.5 ± 7.9 N, p ≤ 0.001). In all gaits, total force for the bridoon was lower than the snaffle bit (all p ≤ 0.001).
Main limitations: Only high-level experienced horses/rider combinations were studied.
Conclusion: Total rein force was less for the DB in trot; and at all gaits there was greater force on the SB snaffle bit than the DB bridoon bit, suggesting potential for greater focal forces being applied to oral structures by the SB snaffle bit than with the DB bits in this level of horse/rider. More work is needed to investigate the biological effects of this.
Ethical animal research: Approved by Hartpury University's ethics and welfare committee URN 2021–126.
Informed consent: Consent was obtained from riders and owners.
Competing interests: None declared.
Funding: Hartpury University Research and Knowledge Exchange Grant and Worshipful Company of Saddlers.
| Period | 17 Sept 2024 |
|---|---|
| Event title | British Equine Veterinary Congress 2024 |
| Event type | Conference |