高清福利片

This explainer published in last week as a companion piece to the ABC TV current affairs special.
It is co-authored by听听from the University of Sydney School of Veterinary Science and Associate Professor in Veterinary Physiology Samantha Franklin from the University of Adelaide.

The use of widespread use of tongue-ties in horse racing in Australia has recently听.

But there are limited data to show that tongue-ties improve racing speeds overall, and there鈥檚 mounting evidence that they can cause stress and injury. Tongue-ties are banned in most non-racing equestrian sports in Australia, and Germany recently听.

What is a tongue-tie?

A tongue-tie is a strap that immobilises a horse鈥檚 tongue by attaching it to the lower jaw (and sometimes to the bit in the horse鈥檚 mouth). The straps may be fashioned from nylon stockings, elastic bands or leather.

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Tongue-ties date back to the 18th century. Early reports suggest that they were used to prevent abnormal noise and airway obstruction, caused by the horse pulling back its tongue and forcing its soft palate backwards. In lay terms, many refer to the horse that does this as having 鈥渟wallowed its tongue鈥� or 鈥渃hoked down鈥�.

In recent years, endoscopy has confirmed that displacement of the soft palate during exercise can obstruct a horses鈥� airway and limit oxygenation, reducing athletic performance.

Exactly how tongue-ties prevent this is unclear, but it is believed that tying the tongue forward听听and larynx and help to stabilise the upper airway.

However it鈥檚听听the tongue-ties are effective. A听听found they did not prevent displacement in over 70% of affected horses.

Furthermore, there are听, and there is no rationale for the use of a tongue-tie for these other conditions.

As well as potentially preventing upper airway obstruction, tongue-ties may stop horses from getting their tongue over the bit,听.

How common are they?

Tongue-ties are banned in most non-racing sports by the international governing body of equestrian sports,听, so are not seen in events like show-jumping, dressage and eventing. (In Australia tongue-ties听, but only under veterinary advice and for a maximum of 10 minutes.)

In both Thoroughbred and harness racing, their use is听. Horses racing with tongue-ties are specified on the race-card, so the scale of their use can be estimated from these data.

Research presented at the 2017 World Equine Airways Symposium revealed that Australian Thoroughbred racehorses听.

This can be compared to the听听reported to wear a tongue-tie in the UK.

Data from听听show that 72 percent of trainers used a tongue-tie on at least one horse over the 5-year period. Similarly, a survey of 535 Standardbred trainers found that听听on one or more horses during training or racing.

Why do tongue-ties matter?

Using relentless pressure to modify a horse鈥檚 behaviour is against the听.

In a recent听, 23 percent of Australian Standardbred trainers reported problems associated with tongue-ties, including lacerations, bruising and swelling of the tongue, difficulty swallowing, and behaviour indicating stress.

Another听听investigated horses鈥� responses to 20 minutes of tongue-tie application at rest in comparison to a sham treatment. (During the sham treatment the horses鈥� tongues were manipulated for 30 seconds to simulate the placement of a tongue-tie.)

Compared to the sham treatment, there was more head-tossing, backwards ear position and gaping during tongue-tie application. Horses with previous experience of tongue-ties showed more head-tossing and mouth-gaping, suggesting that horses did not simply get used to the intervention.

During the recovery phase, lip-licking was more frequent after tongue-tie application than after sham treatment, suggesting that after their tongues are restrained horses are highly motivated to move them. Salivary cortisol concentrations increased after tongue-tie application, indicating a physiological stress response.

These potential problems prompted a recent international equine welfare workshop on听听to score tongue-ties as having a 鈥減rofound transient impact鈥�.

The industry needs to address two separate issues. Firstly, if tongue-ties are being used to address upper airway obstruction then a veterinary diagnosis should be required. There are many causes of breathing noise that are unrelated to palatal issues, and which would not be helped by a tongue-tie.

Secondly, there is the issue of control. If one argues that tongue-ties are needed for safety because they stop the tongue travelling over the bit, then theoretically one is obliged to use them for all horses 鈥� since all horses have the capacity to adopt this evasion.

We need better research to understand exactly how tongue-ties help or harm horses. Given that other equestrian sports are conducted without tongue-ties, many would argue that racing should be as well.

Video recorded for demonstration purposes by听Horses & People听Magazine.

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