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doi:10.1016/j.jv
Journal of Veterinary Behavior (2012) 7, 142-148
RESEARCH
The effect of double bridles and jaw-clamping cranknosebands on temperature of eyes and facial skinof horses
Paul McGreevya, Amanda Warren-Smitha,b, Yann Guisardc
aFaculty of Veterinary Science, University of Sydney, NSW, Australia;bMillthorpe Equine Research Centre, Millthorpe, NSW, Australia; andcSchool of Agricultural and Wine Sciences, Charles Sturt University, Orange, NSW, Australia.
KEYWORDS: Abstract Any apparatus that restricts a horse’s movement can compromise welfare. Eye temperature
bridle;equitation science;horse welfare;nosebands;jaw clamping;
vascular perfusionas measured remotely using infrared thermography is emerging as a correlate of salivary cortisol con-centrations in horses. This article explores the effect on the temperature of the eyes and facial skin ofhorses wearing devices that restrict jaw movements. In certain equestrian disciplines, unacceptableequine oral activity, such as gaping of the mouth, is penalized because it reflects poor training and lackof compliance. This explains the wide range of nosebands and flash straps designed to prevent themouth opening. Some of these nosebands are banned from higher-level dressage competitions in whichdouble bridles are mandatory, possibly because they are regarded as restrictive. Nevertheless, thecurrent international rules overlook the possibility that noseband can appear innocuous even thoughsome designs, such as the so-called crank noseband, can be ratcheted shut to clamp the jaws together.Some equestrian manuals and competition rule books propose that ‘‘two-fingers’’ be used as a spacer toguard against overtightening of nosebands but fail to specify where this gauge should be applied. Thevagueness of this directive prompted us to undertake a small random survey of the finger dimensions ofadult men (n 5 10) and women (n 5 10). There were significant sex differences in the measurementsof fingers of adults (P , 0.001), thus illustrating that the ‘‘two-finger rule’’ is not a reliable guide forstandardized noseband fastening. Infrared thermography was used to measure the temperature of facialskin and eyes of adult horses (n5 5) wearing a double bridle with and without a cavesson noseband. Ataper gauge was developed based on the mean circumference of adult index and middle fingers(9.89 6 0.21 cm), and this was used as a spacer at the nasal planum or beside the mandible when tight-ening the noseband. The nosebands were fastened significantly tighter when the taper gauge was usedbeside the mandible than at the nasal planum (P 5 0.02). Wearing double bridles and nosebands thathad been tightened with and without the taper gauge caused an increase in eye temperature comparedwith baseline values (P 5 0.012), and the tighter the noseband was fastened, the cooler the facial skinof the horse (and, presumably, the greater the impairment of vascular perfusion) when compared withbaseline values (P 5 0.016). This study suggests that horses wearing double bridles and tight nose-bands undergo a physiological stress response and may have compromised vascular perfusion.
reprint requests and correspondence: Paul McGreevy, BVSc, PhD, Faculty of Veterinary Science (B19), University of Sydney, NSW, 2006,
612 93512810; Fax: 1612 93513957.
ee front matter � 2012 Elsevier Inc. All rights reserved.
eb.2011.08.001
McGreevy et al Effect of double bridles and jaw-clamping crank nosebands 143
Consequently, on welfare grounds, the use of nosebands that cause any constriction of jaw movementshould be reviewed as soon as possible.� 2012 Elsevier Inc. All rights reserved.
Introduction
The Federation Equestre Internationale (FEI, 2009) statesthat it ‘‘relentlessly concerns itself with the welfare of thehorse, which is paramount and must never be subordinatedto competitive or commercial influences’’ (Anon., 2011),and its rules enshrine principles intended to safeguard horsewelfare. In dressage, many restrictive nosebands are bannedfrom higher-level competitions in which double bridles aremandatory. This is because when a bridled horse attemptsto open its mouth, it is thought to be expressing oral dis-comfort (Christensen et al., 2010) and conflict (McGreevyand McLean, 2010). Fighting the bit suggests a trainingdeficit and is listed among various evasions and resistancesthat can attract penalties for riders in competition. There-fore, it is surprising to find that, despite the current rules,a very popular piece of gear, the plaindcavessondnoseband, permitted within FEI rules, can be used inways that may profoundly compromise horse welfare.
The rules of dressage stipulate that a cavesson nosebandmay ‘‘never be as tightly fixed so as to harm the horse’’(FEI, 2009). However, they fail to specify how tightness ofthe cavesson is to be measured. This has permitted a steadycreep in the use of apparently plain nosebands that can betightened to the extent that they clamp the jaws shut(McLean and McGreevy, 2010a). The United StatesEquestrian Federation (USEF) states that a noseband maynever be so tightly fixed that it causes severe irritation tothe skin (USEF, 2009). These days, most plain nosebandsare padded, mainly because they can be tightened somuch that, were it not for the padding, they would resultin pressure sores (McGreevy and McLean, 2010).
Although absent from the FEI rules, the most commonadvice on noseband fitting in equestrian textbooks andmanuals is that nosebands should be fitted so that 2 fingerscan be passed between the noseband and the horse’s face(Anon., 1956; Stecken, 1977; Huntington et al., 2004). Sig-nificantly, these texts fail to specify whether the 2 fingersmust be those of an adult or of which sex, how far underthe noseband the fingers must be able to pass, or preciselywhere these measurements should be taken. At first glance,such details may seem to be of only academic importance,until one recalls that the labial cutting edge of equine mo-lars is naturally sharp. Any pressure through the cheek willtend to press the buccal lining against these sharp points. Ifthe generic 2-finger space estimate is applied alongside themandible, it may allow nosebands to be applied moretightly than if it were applied in a site with minimal soft-tissue (i.e., the bridge of the nose or nasal planum). There-fore, tight nosebands affect most horses significantly, even
if they have no bit in their mouths, let alone if they have 2,as is the case in elite dressage competitions, where a doublebridle is mandatory. Extreme tightening is thought to in-crease the bitted horse’s compliance and responsivenessto rein pressure, perhaps by sensitizing its mouth(McGreevy and McLean, 2010). This benefits the rider be-cause the horse appears to become more ‘‘submissive’’(FEI, 2009). However, by increasing the sensitivity to bitpressure, the rider risks the horse showing signs of painor resistance, and that is why some riders are keen tomask the horse’s natural comfort-seeking responses byrestricting jaw and tongue movements that disclose resis-tance (McLean and McGreevy, 2010b).
Advances in infrared thermography and image process-ing software have recently resulted in applied thermalstudies on horses (Eddy et al., 2001; Tunley and Henson2004; Ciutacu et al., 2006). The principles underlyingthermography are simple. Every surface emits infraredradiation linearly related to the fourth power of its temper-ature. Infrared thermographers (or ‘‘thermal cameras’’) aredevices that capture the infrared radiation emitted from asurface and display this information in a false color picto-rial representation (i.e., a thermograph). The technique isvery sensitive (typically 0.1�C accuracy) and is well suitedto absolute as well as relative observations.
Thermography is a noninvasive procedure (Kuleszaet al., 2004; Ciutacu et al., 2006; Ludwig et al., 2007;Yanmaz et al., 2007; Tattersall and Cadena, 2010), allowinghorses to be examined from a distance and thus to minimizeany unwanted influences. Surface temperatures of animalsare readily detected using thermography (Jodkowska andDudek, 2003; Tattersall and Cadena, 2010). This methodol-ogy has been widely used to reliably identify areas ofabnormal body surface temperature in horses presentingwith lameness (Eddy et al., 2001; Ciutacu et al., 2006;Yanmaz et al., 2007) or vertebral column pathology(Tunley and Henson 2004), as well as to evaluate trainingprogress (Jodkowska and Dudek, 2003).
Finally, thermography has also been used to assess stressin rabbits (Ludwig et al., 2007), cattle (Stewart et al., 2007,2008a,b), and horses (Burton et al., 2010; Hall et al., 2010).Ludwig et al. (2007) reported that one of the best areas forthermographic measurement of stress in animals is the eye.Increase in eye temperature was positively correlated tocortisol concentrations in response to pain (Stewart et al.,2008b,c), stress (Ludwig et al., 2007; Stewart et al.,2007), and fear (Stewart et al., 2008a). Of these relation-ships, the correlation with circulating cortisol is arguablythe most important, as increased circulating concentrationof cortisol has been strongly established as a reliable
144 Journal of Veterinary Behavior, Vol 7, No 3, May/June 2012
indicator of physiological stress in animals (Alexander andIrvine, 1998; Merl et al., 2000). Interestingly, increases ineye temperature were reported to accompany increased cor-tisol concentrations in horses that were lunged in a PessoaTraining System (Hall et al., 2010), a constrictive apparatusused by some as a regular training tool.
To establish a working model of a standard ‘‘two-finger’’taper gauge, the dimensions of the index and middle fingersof the dominant hands of a random group of adult men andwomen were measured. The mean of these measurementswas used to create a ‘‘two-finger’’ taper gauge. Then,infrared thermography was used to assess the effect on theskin and eye temperature of horses wearing a double bridlewith a cavesson noseband in 4 different ways: unfastened,tightened to allow only a ‘‘two-finger’’ taper gauge at theside of the mandible, tightened to allow only a ‘‘‘two-finger’’ taper gauge at the nasal plane, and fully tightened.Responses were then compared with temperatures recordedwhen the horses were wearing no noseband at all.
Figure 1 A and B: An example of the thermographs recordedfrom the horses, with and without a double bridle. *Indicates theanatomical landmark that was used to measure skin temperature.
Materials and methods
Assessment of the dimensions of 2 fingers ofadult subjects
The fingers of 10 male and 10 female subjects.18 yearsof age were measured. The midpoint of the intermediatephalanx of the digitus medius (middle finger) of theirdominant hand (Pfeil et al., 2009) was identified and markedwith a pen. The following 3 measurements were taken at thatpoint:
1. Height of digitus medius when viewed from a lateralaspect.
2. Width of digitus secundus (index finger) and digitusmedius side-by-side.
3. Circumference of digitus secundus and digitus mediusside-by-side.
The mean dimensions from these recordings were usedto make a taper gauge, designed as an analog of 2 humandigits side-by-side. This was constructed from 2 tapered13-mm (in diameter) garden sprinkler spikes (www.wisewally.com.au) adhered together. The point on their shaft atwhich these two cones had an accumulated circumferenceof 9.89 cm (mean circumference of digitus secundus and dig-itus medius side-by-side) was marked on the resultant probe.
Animals
Five horses of varying age (mean: 17.8 6 3.9 years),breed (3 Warmbloods and 2 Thoroughbreds), sex (1 stal-lion, 1 gelding, 3 mares), and height (162.6 6 0.04 cm)were recruited into the study. All were riding horses and allwere familiar with snaffle bridles, most had worn double
bridles previously. They were housed in paddocks (approx-imately 12 acres/5 ha), with mares and geldings in onepaddock and the stallion in another. They all had freeaccess to improved pastures and mineral blocks, as wellas supplementation with lucerne hay, to meet NationalResearch Council (1989) equine nutritional guidelines.All horses were handled on a daily basis for feeding andgeneral health checks.
Peripheral temperature recordings
On a single day, each horse was brought in from pasturewith a standard web headcollar and cotton lead, led to thetest area (i.e., a familiar stable block), and was held by afamiliar handler for 2 minutes of acclimatization. After this2-minute period, the horse was groomed to ensure that thehead was clean, the nosepiece of the headcollar was thenundone, and baseline readings of eye temperature and theskin temperature at the junction of the facial crest and theanterior margin of the masseter muscle were recorded once
Figure 2 Eye temperature differences in horses (n 5 5) in re-sponse to wearing a double bridle and a crank noseband unfas-tened (U), fastened using a taper gauge at the nasal plane(TGN), fastened using a taper gauge at the mandible (TGM),and fastened without using a taper gauge (NTG). *Indicates a sig-nificant difference at the level P , 0.05.
Figure 3 Skin temperature differences in horses (n 5 5) inresponse to wearing a double bridle and a crank noseband unfas-tened (U), fastened using a taper gauge at the nasal plane (TGN),fastened using a taper gauge at the mandible (TGM), and fastenedwithout using a taper gauge (NTG). *Indicates a significant differ-ence at the level P , 0.05. **Indicates a significant difference atthe level P , 0.01. ***Indicates a significant difference at thelevel P , 0.001.
McGreevy et al Effect of double bridles and jaw-clamping crank nosebands 145
a minute for 5 consecutive minutes (Figure 1A, B). Theserecordings were made using an M8 infrared thermographer(Wuhan Guide Infrared Technology Co., Ltd., Wuhan,China). This camera captures 160 ! 120 pixel thermo-graphs with a resolution of 0.1�C, simultaneously with avisible image.
External circumference of the nose
The external circumference of each horse’s nose wasmeasured with a tape measure placed just under the facialcrest, and this measure was repeated because the horseswere given a piece of carrot so that the measurementobtained then reflected the external circumference of thejaw when chewing. The horses were then bridled accordingto a predetermined randomized order and were tested in
Table 1 P values for comparisons of eye temperatures amongthe 4 treatments at time 5 and at time 10 in horses (n 5 5) inresponse to wearing a double bridle and a crank nosebandunfastened (U), fastened using a taper gauge at the nasalplane (TGN), fastened using a taper gauge at the mandible(TGM), and fastened without using a taper gauge (NTG)
Treatment U TGN TGM NTG
Time 5Means 20.10 21.46 21.14 21.18U –TGN 0.771 –TGM 0.601 0.816 –NTG 0.779 0.995 0.832 –
Time 10Means – 0.14 20.08 20.13U –TGN – –TGM – 0.749 –NTG – 0.716 0.951 –
pairs, except for the stallion. The bridle used was a full-sized standard double bridle comprising a bit and bridoon,both of medium thickness. The bit was of Weymouth stylewith a smooth low port (Keiffer Saddlery, Westport, CT;http://www.kieffer-saddle.com/double_bridles/). The reinswere left off the bridle. The bridle was fitted with a paddedcrank noseband that was fastened according to the random-ized treatments. The noseband was fitted using the tapergauge, as described previously. The taper gauge was ap-plied to the most caudal margin of the noseband in 2 posi-tions, at the nasal planum and lateral to the left mandible,and was removed after the noseband had been fastened.
Temperature recordings of the eye and skin were takeneach minute for each of the following treatments:
1. Bridled but with the noseband unfastened (for 5 consec-utive minutes);
2. Bridled with the noseband tightened using the tapergauge at the most caudal margin of the noseband onthe nasal planum (for 10 consecutive minutes);
3. Bridled with the noseband tightened using the tapergauge at the most caudal margin of the noseband lateralto the left mandible (for 10 consecutive minutes);
4. Bridled with the noseband tightened without using thetaper gauge (for 10 consecutive minutes).
After each bridled session, each horse was then allowedto stand for 10 minutes without the bridle or noseband inplace (i.e., recovery session), after which the facial tem-peratures were again recorded. The horses were thenrebridled and the noseband adjusted according to therandomized order of treatments and the procedure repeated.
Data analysis
Differences in the circumference of the horses’ noseswhile the horses were still and while chewing the feed wereanalyzed using a paired t test. The extent of the noseband
Table 2 P values for comparisons of skin temperaturesamong the 4 treatments at time 5 and at time 10 in horses(n 5 5) in response to wearing a double bridle and a cranknoseband unfastened (U), fastened using a taper gauge at thenasal plane (TGN), fastened using a taper gauge at themandible (TGM), and fastened without using a taper gauge(NTG)
Treatment U TGN TGM NTG
Time 5Means 1.44 2.20 0.86 0.35U –TGN 0.293 –TGM 0.422 0.049 –NTG 0.134 0.007 0.454 –
Time 10Means – 0.10 0.52 0.25U –TGN – –TGM – 0.534 –NTG – 0.819 0.694 –
146 Journal of Veterinary Behavior, Vol 7, No 3, May/June 2012
tightening during the various treatments was assessed by theposition of the buckle in terms of the number of holes alongthe noseband strap. These data were analyzed with 1-wayanalysis of variance (ANOVA). Temperature differenceswere calculated by subtracting the temperature at the 10 re-peated test readings from the relevant baseline temperature.A split plot in time ANOVAwas used to analyze these tem-perature differences. However, because one treatment (un-fastened) had fewer observations, a linear mixed modelwith a residual maximum likelihood algorithm was used.A residual maximum likelihood analysis is identical to anANOVAwhen the ANOVA assumptions hold, but is appro-priate for unequally replicated experiments and forexperiments in which the treatment variance changes orthe data are correlated. All statistical analysis was per-formed with GenStat 10th edition (VSN International Ltd.,Hemel Hempstead, Hertfordshire, United Kingdom).
Results
Finger dimensions
The mean height of the midpoint of the intermediatephalanx of the digitus medius was 1.59 6 0.05 cm. Themean width of the midpoint of the intermediate phalanx ofthe digitus secundus and digitus medius side-by-side was3.87 6 0.09 cm. The mean circumference of the digitussecundus and digitus medius side-by-side was 9.89 60.21 cm. None of the finger measurements differed withhandedness. Males had significantly larger height of digitusmedius (P 5 0.026), width of digitus secundus and digitusmedius (P , 0.001), and circumference of digitus secundusand digitus medius (P , 0.001) than females.
External circumference of the nose
The mean external circumference of the nose was 65.561.4 cm, which was significantly less than the circumferenceof the nose when the horses were chewing (68.6 6 1.7 cm;t 5 24.14; df 5 4; P 5 0.014).
Noseband adjustments
There were significant differences in the tightness of thenoseband as measured by distance along the strap thebuckle had travelled (the lower the number of holes, thelooser the noose around the nose). Using the taper gauge onthe nose when fastening the noseband resulted in theloosest fitting (68.3 6 1.6 cm) when compared with usingthe taper gauge on the mandible (62.8 6 1.8 cm) or whennot using the taper gauge (60.3 6 1.5 cm; P 5 0.020).
Peripheral temperature recordings
EyeThere was a significant increase in eye temperature over
time (F5 2.51,P5 0.012). However, the interaction of treat-ments and time was not significant (F 5 0.94, P 5 0.548;Figure 2 and Table 1).
SkinThere was a significant decrease in skin temperature
over time (F 5 1.89, P 5 0.016; Figure 3 and Table 2) and,when compared with having the noseband undone, therewas a trend for lower skin temperature when the nosebandwas fastened without using a taper gauge (P 5 0.062) andwhen the noseband was fastened using the taper gauge atthe mandible (P 5 0.051).
Discussion
The differences between the sexes for finger circumferencedemonstrate that using a ‘‘two-finger’’ assessment of nose-band tightening as a standard to protect horse welfare(Anon., 1956; Stecken, 1977; Huntington et al., 2004) isflawed. The current data on finger dimensions justify the es-tablishment of an objective standard taper gauge for thispurpose. More data on finger dimensions may increasestakeholder confidence that a universal taper gauge is rep-resentative of the general population in this metric. Clearly,some clarification is needed to specify the exact site andmethod of tightening to be used with nosebands on horsesand this should be consistent regardless of who is fasteningor checking a noseband on a horse.
Tight nosebands on horses have welfare implicationsbecause, when fitted tightly, they prevent the horse frombeing able to move its jaw. This is troubling for severalreasons. First, clamping the jaw shut prevents the horsefrom being able to show normal behavior (i.e., opening the
McGreevy et al Effect of double bridles and jaw-clamping crank nosebands 147
mouth for licking/chewing and/or resalivation of thetongue). If, as is suggested by data from the currentpopulation of horses, an external jaw circumference of aminimum of 68.6 cm is required to allow horses to performa natural response and also one that is considered desirablein dressage, then tightening without a taper gauge or usinga taper gauge at the mandible is contraindicated.
Second, preventing a bridled horse from opening itsmouth means that it cannot show any oral conflict behaviors.This is of particular importance because, in the sport ofdressage, horses are judged on their ‘‘submissiveness,’’which includes their ‘‘lightness and ease of movements,acceptance of the bridle and lightness of the forehand’’(FEI, 2009). This is to be assessed by the lack of ‘‘resis-tance,’’ ‘‘evasion,’’ ‘‘putting out the tongue,’’ ‘‘keeping thetongue above the bit or drawing it up altogether,’’ as wellas ‘‘grinding the teeth’’ (FEI, 2009). However, if the horsehas its jaw clamped shut, it is not able to show theseresponses and therefore judges may mistakenly considerthat the horse is showing submission when in reality it isnot. Recent evidence suggests that submission marks aresubject to the most variability of all the collective marksin dressage (Hawson et al., 2010). This is most unfortunatebecause submission is the only element of the dressagescore that may act to safeguard horse welfare (McLeanand McGreevy, 2010b). Masking horses’ responses withgadgets such as tight nosebands may contribute to thisevident lack of consensus among judges.
Using the taper gauge on the nasal planum resulted inthe loosest fitting of the noseband. However, it was still notloose enough to allow the horses to chew gently, a responseconsidered to be desirable in a dressage horse (Podhajsky,1967; Anon., 1990). For instance, the noseband fastenedusing the taper gauge at the nasal planum was on averageat hole 6.8. This equated to a circumference of 68.3 cm,which, from the measures of the external circumferenceof the noses of the horses used in this study, is barelyenough to permit sufficient movement in the jaws for gentlechewing to occur (68.6 cm required). Clearly, other normalbehaviors such as yawning would be prevented even at thismost conservative level of tightening. Differences in thenoseband circumference with the varied placement of thetaper gauge (on the nose, mandible, or absent) highlightsthe need for clarification as to the precise location at whichany standard gauge should be applied. As horse comfortand welfare are at stake, any reliance on fingers as a gaugeshould be abandoned.
Furthermore, according to the FEI Rules for DressageEvents (2009), when a horse is ‘‘on the bit’’ it may ’’quietlychew the bit.’’ Equitation texts report that when a horse ismouthing the bit, it is generally considered a good sign, as it isbelieved to indicate that the horse is relaxing and ‘‘accept-ing’’ the bit (Podhajsky, 1967; Anon., 1990; Kienapfel andPreuschoft, 2010). It is doubtful that a horse would beable to show any mouthing of the bit when wearing a tightnoseband.
The increased eye temperature of the horses over timesuggests that physiological stress responses increased(Ludwig et al., 2007; Stewart et al., 2007, 2008a,b,c; Hallet al., 2010). The importance of this outcome is that itimplies that the introduction of a double bridle can distresssome horses. It may be that a horse requires a significantperiod (i.e., longer than the 10 minutes of the current treat-ment period) before it can habituate to having 2 bits in itsmouth. This is further highlighted by the fact that the horseswere not worked at all during the testing time but weremerely standing still in a familiar environment with famil-iar carers. It would be interesting to see how eye tempera-tures respond under a similar experimental design thatincorporates rein tensions typical of a dressage test. Thedata herein imply that the rules stating that double bridlesare compulsory at higher levels of competition must bequestioned, especially given that the first clause in theCode of Conduct requires that the welfare of the horse isparamount (FEI, 2009).
The changes in the temperature of the skin of the horsessuggest that the pressure of the noseband being on thehorse, even when done up according to the guidelines, issufficient to compromise local cutaneous perfusion. Itwould be interesting to see what the effects of thisconstriction would be over a period of .10 minutes. Giventhat the rules of dressage state that a cavesson nosebandshould ‘‘never be as tightly fixed so as to harm the horse’’(FEI, 2009) and that the USEF states that a ‘‘cavesson nose-band may never be so tightly fixed that it causes severe ir-ritation to the skin’’ (USEF, 2009), it seems fundamentallyproblematic that, even when using a gauge in the mostconservative position, there are potentially detrimentaleffects to the skin of the horse. When a horse attempts toopen its mouth (e.g., in response to strong bit pressure),the tension in the noseband must increase. So, it will beimportant to study the effects on local cutaneous perfusionof relentless bit pressures, such as are characteristic ofsome contemporary training practices.
Conclusions
The commonly recommended 2-finger assessment of nose-band fastening is inherently flawed and an objectivemeasure of this parameter is definitely and urgentlyrequired. Similarly, this study exposes the need for clari-fication on precisely where any standardized gauge shouldbe applied. If the welfare of horses in training is to beconsidered paramount, as prescribed by the FEI (2009),these measures must be addressed immediately and mustreflect a horse’s need to chew normally while wearing bri-dles and nosebands. By clamping the jaws of performancehorses shut, competitors prevent them from exhibiting nor-mal responses, such as gentle chewing of the bit, and fromrevealing any oral conflict, an outcome that speaks of a def-icit in training and that attracts penalties. The increased eye
148 Journal of Veterinary Behavior, Vol 7, No 3, May/June 2012
temperatures reported here show that merely wearing nose-bands and double bridles seemed to increase the stress re-sponses of the horses, even without any rein tension.Similarly, the significant changes in the skin temperatureson the horses’ faces show that tight nosebands can interferewith local vascular perfusion. In most equestrian disci-plines, gear stewards check whether all equipment usedon horses competing in different events complies with thespecified regulations. By implementing a strategy that canbe used to fix/remove/loosen nosebands, stewards couldensure that the detrimental effects reported here could beeliminated or at least lessened.
Acknowledgments
The authors thank Liz McFarland for assistance in horsehandling and Cameron Harris and Fred Smith from Mitre10, Orange, NSW, for their advice about suitable materialsfor the current gauge. Dr. Mick O’Neill (www.stats.net.au)provided excellent statistical advice.
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