Bit-related lesions in Icelandic competition horses

Abstract

BackgroundOral lesions related to the use of the bit and bridle are reported to be common findings in horses worldwide and represent an important animal welfare issue. In order to provide an overview of bit-related lesions in Icelandic competition horses, a field examination of the rostral part of the oral cavity was performed in 424 competition horses coming to the two major national horse events in Iceland in 2012. Records from repeated examination of 77 horses prior to the finals were used to assess potential risk factors.ResultsMild lesions were recorded in 152 horses (36%) prior to the preliminary rounds. They were most often located in the commissures of the lips and the adjacent buccal mucosa (n = 111). Severe lesions were found in 32 (8%) horses. For 77 horses examined prior to the finals, the frequency of findings in the area of the mandibular interdental space (bars of the mandible) had increased from 8% to 31% (P < 0.0001). These findings were most often (16/24) regarded as severe. The presence of lesions on the bars was strongly associated to the use of curb bits with a port (OR = 75, P = 0.009).ConclusionsBit-related lesions were found to be a general problem in Icelandic competition horses. The type of bits used influenced both the location and the severity of the lesions. The use of curb bits with a port was found to be a decisive risk factor for lesions on the bars of the mandible, most of which were regarded as severe. The results also raised questions about the head and neck carriage demanded for the competition horses.

Lesions associated with the use of bits, nosebands, spurs and whips in Danish competition horses

“…presence was strongly associated with using a snaffle bit [5]. In contrast, using a ported curb bit was more likely to be associated with lesions on the bars of the mouth.…”

“…Prior to the start of a multi‐day competition, 43% of Icelandic horses had oral ulcers, most of which were mild and located around the commissures of the lips. When re‐evaluated prior to the final round of competition, the prevalence of ulcers at the lip commissures had not changed, and their presence was strongly associated with using a snaffle bit . In contrast, using a ported curb bit was more likely to be associated with lesions on the bars of the mouth.…”

Determining a Welfare Prioritization for Horses Using a Delphi Method

“…There has been a recent increase in scientific studies assessing the impact of training, tack use and competition on equine welfare. For example, studies have shown significant lesions in the mouths of Finnish trotters and Icelandic horses when used in competition from the action of the bit [7,32]. The use of coercive hyperflexion of the head and neck or Rollkur, for example in dressage horses, has been shown to cause adverse behavioural [15] and physiological indicators [33], suggesting increased stress in these animals compared to working in a less flexed position.…”

Mouth Pain in Horses: Physiological Foundations, Behavioural Indices, Welfare Implications, and a Suggested Solution

“…The formation of bone spurs in affected horses is apparently due to inflammation associated with repeated incidents of bit-induced bruising, laceration, and/or ulceration of the interdental gums [7,[121][122][123]. Such gum lesions reportedly occurred in 26% of 261 Trotters observed after a race [124], increased from 8% before to 31% after events in 77 competition horses [125], and were more common and severe in racehorses than polo ponies [120]. All such lesions are painful [107], and human experience would suggest that the intensity of that pain would be increased when there is further direct compressive contact between these lesions and a bit.…”

“…Nevertheless, several observations suggest that the tongue may be somewhat protected from bit-induced penetrative injuries. Studies that reveal significant bit-related injuries at multiple oral sites report no or very low occurrences of significant tongue lacerations or ulcers [120,124,125,129,130]. The tough keratinized squamous epithelial lining of at least the dorsal surface of the tongue [131] may contribute to this, but it might also make bruises from non-penetrative bit-related compression more difficult to detect.…”