Double Bridles: Lightness and Finesse, or Blue Tongues and Pain
In light of the recent photos taken by Crispin Parelius Johannessen of three top international dressage horses with oxygen deprived blue tongues, questions have risen around the use of double bridles at top level. This year has seen several equine welfare scandals, from top riders being investigated, FEI judges rewarding of hyperflexion and now the blue tongue images, there is a huge increase in the concern for equine welfare in horse sport.
What is a blue tongue?
Under normal conditions, horses tongues are pink in colour. When oxygen is deprived from that area, the horses tongue turns grey and blue. This has been seen to be caused by the high pressure of the bit, or bits for double bridles. Dr. David Marlin gave a explanation of this on a recent social media post “The restriction is so tight as to overcome arterial pressure and prevent arterial blood supplying the free section of the tongue beyond the bit. At the same time, there would be no venous return. So, the oxygen in the tongue would be used up, changing the colour from red/pink to blue” You can read his full post on his Facebook Page "Dr David Marlin".
From the article the blue tongue photos appeared, Veterinarian Christine Levring, a member of NCED, Nordic College of Equine Dentistry, and leader of an international group for research and knowledge on bitting explained “that it's how hard the rider holds the reins in combination with the design of the bit that causes the horse's tongue to be compressed, blocking the passage of blood and causing oxygen deprivation. A condition that is both painful and can be dangerous. It can go into necrosis if it's for a long time”
Why do we use double bridles?
Double bridles are used in higher levels of dressage and within the show ring. Horses who have been trained in a snaffle, are ready to understand and accept a lighter and more refined aid from the riders hand (Batty-Smith, 2010). The bridoon bit helps to elevate the horse or bending the horse. The curb is responsible for bringing the head near towards the vertical. As such, a good rider should be able to use both bits effectively to achieve the exact riding posture or maneuver that is wanted from the horse itself (Jackson, 2017). It is a FEI mandatory rule for horses to be ridden at international Grand Prix competitions, with a double bridle.
EEWC Welfare recommendations for the option of double bridles
In 2022 the FEI set up the Equine Ethics and Welfare Commission. The Commission was tasked with addressing societal concerns about the use of horses in sport and creating a blueprint to future-proof equestrian sports, as well as providing independent advice and recommendations to the FEI to ensure equine welfare is safeguarded through ethical, evidence-based policy and practices (EEWS,2022). There was a total of 30 recommendations made by the EEWC, 24 presented to the Sports Forum and 6 early recommendations. Of the 6, one was made in regard to double bridles.
“Double bridles should not be mandatory in any equestrian discipline”.
When this recommendation was given, to make double bridles optional, the FEI rejected this proposal and did not add it into the draft 2024 rulebook. The ISES (International Society of Equitation Science) fully supported the 30 recommendations the EEWC gave, including the optional use of double bridles. The **ISES wrote an open letter8* to the FEI to say “ISES is supportive of there being choice for riders in favour of their horses’ welfare in relation to use of the double bridle. ISES is disappointed that the FEI proposed rule changes do not reflect the early recommendation made by the EEWC regarding deregulating the mandatory use of a double bridle for any discipline”
As a response to this, the International Dressage Riders Club and the International Dressage Trainers Club wrote a strongly worded letter to the FEI and the ISES. The letter says “The opposition to the double bridle comes from a lack of understanding regarding how and why the double bridle is used. Yes, the misuse of the double bridle can lead to force and injury, this is true with the snaffle or any other bit or even a hackamore”
“Any indication of injury to the horse results in elimination. This is a powerful incentive to ensure riders are judicious in their use of the reins”
“Therefore, we believe that neither the double bridle nor spurs represent a welfare risk to horses and there exist sufficient controls to ensure against their misuse. To make these two pieces of equipment optional would have no positive impact on horse welfare”
“the only real defense is to adhere to the principle of using objective scientific evidence to establish rules regarding welfare”
This letter says that indication of injury due to the double bridle leads to elimination, yet three top dressage horses were photographed with blue, oxygen deprived tongues, went on to place and win at the top level of the sport this year. The international dressage riders club say that double bridles do not represent a welfare risk to horses, yet blue tongues have been sighted and reported on for over 15 years.
What does Science say?
In a study investigating the effect of double bridles on eye temperature and facial skin of horses (McGreevy et al., 2012) found that wearing double bridles caused an increase in eye temperature compared to baseline values. It was also found that the tighter the noseband was fastened, the cooler the facial skin of the horse (and, presumably, the greater the impairment of vascular perfusion) when compared with baseline values.
The study suggests that horses wearing double bridles undergo a physiological stress response and may have compromised vascular perfusion.
The bits of a double bridle are often said to function independently of each other (Equine Knowledge, 2020), but researchers found evidence to dispute this. In a study looking to Characterize the Intrinsic Operation of Horse Bridles and Bits (Cross et al., 2017) found some interesting results when collecting data on the curb and bridoon bit. The cheek piece and rein were fitted with a tension monitor, and three bits were tested. One of which was the curb bit of a double bridle. When tested on its own, there was little to no tension on the cheek piece of the curb bit, when the rein was not engaged.
When the bridoon bit was added to the double bridle, there was tension recorded on the curb bit cheek piece of up to 15 newtons (1.5KG) when the rein tension was at 0 newtons.
It was concluded by the researchers that there was a clear interference from the bridoon bit, and these bits do not seem to work independently.
When looking to conflict behaviours in horses, it has been found that 68% of 123 top level dressage horses showed their mouth open during tests for more than 10 seconds (Dyson & Pollard, 2021) It was said by the researchers that the effect of the double bridle on mouth opening needs further investigation, as 44% of sport horses (Dyson & Pollard, 2020) and 45% of three day event dressage horses (Dyson & Ellis, 2020) showed mouth opening, but these horses had snaffle bits and the top level dressage horses had a much higher occurrence of it. Unusual oral behaviour was also found in 100% of horses at the warm up of Grand Prix special (CDIO5*) of the CHIO in Aachen (Kienapfel et al., 2021).
Conclusions
It is said by the IDRC & IDTC that the double bridle does not represent a welfare risk, even when the instances of horses with blue tongues is increasing. They said in their open letter that indication of injury from the double bridle results in elimination, yet riders win at international level while riding horses with oxygen deprived tongues. It has long been said that double bridles have independently working bits, when a study has found quite the opposite. These traditional ways and procedures are in the midst of change, presenting an opportunity for better horse welfare. The EEWC are committed to ensuring horses welfare is upheld in sport, and recommends to allow double bridles to be optional in all disciplines and this needs to be brought into our sport.
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References
McGreevy, P., Warren-Smith, A. and Guisard, Y. (2012) ‘The effect of double bridles and jaw-clamping crank nosebands on temperature of eyes and facial skin of horses’, Journal of Veterinary Behavior, 7(3), pp. 142–148. doi:10.1016/j.jveb.2011.08.001.
Double bits (2020) Equine Knowledge. Available at: https://www.equineknowledge.co.uk/free-trial/bhs-stage-3-course-2-2/stage-3-care/4-bits-bitting/double-bits/ (Accessed: 25 March 2024).
Cross, G.H. et al. (2017) ‘Application of a dual force sensor system to characterize the intrinsic operation of horse bridles and bits’, Journal of Equine Veterinary Science, 48. doi:10.1016/j.jevs.2016.01.017.
Dyson, S. and Pollard, D. (2021) Application of the ridden horse pain ethogram to elite dressage horses competing in World Cup Grand Prix competitions, MDPI. Available at: https://www.mdpi.com/2076-2615/11/5/1187/htm (Accessed: 25 March 2024).