Applied Animal Behaviour Science

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1 Applied Animal Behaviour Science 133 (2011) Contents lists available at ScienceDirect Applied Animal Behaviour Science journa l h o me pag e: Variables affecting the prevalence of behavioural problems in horses. Can riding style and other management factors be significant? Simona Normando a,, Lieve Meers b, William Ellery Samuels c, Massimo Faustini d, Frank O. Ödberg b a Padua University, Dipartimento di Scienze Sperimentali Veterinarie, Viale dell Università 16, Agripolis, Legnaro Padova, Italy b Ghent University, Department of Nutrition, Genetics, and Ethology, Heidestraat 19, 9820 Merelbeke, Belgium c City University of New York, College of Staten Island, Staten Island, Victory Boulevard, New York, USA d University of Milan, Department of Veterinary Sciences and Technologies for Food Safety, Via Celoria 12, Milano, Italy a r t i c l e i n f o Article history: Accepted 6 June 2011 Available online 1 July 2011 Keywords: Horse Management Problem behaviour Riding style Saddle Stereotypies a b s t r a c t The effects of riding style and various management factors on the prevalence of stereotypies and other behavioural problems among 346 mixed-breed saddle horses (phase 1) and 101 Arabian horses (phase 2) were analysed through a questionnaire answered by owners. In phase 1, the questionnaire data were partially validated through 20-min observations of 81 (23.3%) of the cases. Results indicate that horses primarily ridden in the English style were reported to be significantly more likely to display stereotypies (p < 0.001), problems when transported (p = 0.001), multiple behavioural problems (p < 0.001), and to have more restrictive stabling (p < 0.001) than horses ridden with other styles. When only Arabian horses were assessed in phase 2, however, there was no significant difference in behavioural problems between the Arabian horses ridden English style versus other riding styles. However Arabian horses were housed less restrictively than horses in phase 1 and English riding style and restrictive stabling tended to exacerbate each other s association with stereotypies. Management-related effects were found when, e.g., horses housed in restrictive stabling were more frequently reported to show locomotion stereotypies (p = 0.02) and those denied ad libitum hay displayed stereotypic wood-chewing behaviour (p = 0.02). To aid diagnosing and prioritizing interventions and care, the most predictive subsets of factors were computed for the various problem behaviours. E.g., among saddle horses, a statistical model comprised of the main riding style, duration of access to a paddock, and horse s age predicted whether a horse was reported to display any behavioural problem 62% of the time. This study supports the effects of management and handling on the prevalence of behavioural problems, and helps prioritize the relative importance of broad management categories on equine welfare. In particular, it underscores the importance of riding style on the well-being of saddle horses Elsevier B.V. All rights reserved. 1. Introduction Behavioural problems here encompassing both abnormal and undesirable behaviours, including Corresponding author. Tel.: ; fax: address: simona.normando@unipd.it (S. Normando). stereotypies are important concerns in equine practice and constitute a topic that has received considerable, recent, scientific attention (Clegg et al., 2008; Cooper et al., 2002; Hausberger et al., 2008; Henderson and Waran, 2001; Hockenhull and Creighton, 2010; Johnson et al., 1998; McAfee et al., 2002; Mills and Riezenbos, 2005; Thorne et al., 2005; Visser et al., 2008; Wickens and Heleski, 2010). Abnormal behaviours here denote /$ see front matter 2011 Elsevier B.V. All rights reserved. doi: /j.applanim

2 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) pathologies usually resulting from a chronic conflict situation; undesirable behaviours will refer to behaviours humans typically consider annoying. It is beyond the scope of this study to review definitions of the concept of abnormal, which is controversial even in the human physiology literature, and, hence, would require a lengthy examination. A growing body of research is beginning to lend some clarity to the cause and aetiology of problem behaviours among horses. Although it is true that stereotypies (such as crib-biting and pacing) are complex and of varied aetiology (Mason, 1991), many authors find that the majority of these problems in horses are linked to management issues such as stabling, breeding, and feeding practices, and to the management of foals at and around their weaning (for a review see Wickens and Heleski, 2010). In turn, the management of affected horses is influenced (usually in the sense of greater isolation) by the widespread belief among those in the horse world that behaviours including problem behaviours can be learnt or copied from other horses, rather than resulting from less-than-ideal housing and management (McBride and Long, 2001). It seems intuitively logical that stereotypic and other problem behaviours will be more prevalent when management practices place horses in conditions quite different from natural ones to which they are adapted (Kiley- Worthington, 1997; Mills and Nankervis, 1998). For example, Mills and Macleod (2002) and Nicol et al. (2002) suggested that crib-biting develops in order to decrease stomach acidity resulting from a diet of few, concentrated meals quite antithetical to historic equine grazing practices. Administration of antacid buffers decreased crib-biting in a dose-dependent way according to a nonsignificant tendency. However, these results have not been confirmed by more recent studies using virginiamycin or omeprazole (Freire et al., 2008; Toewe et al., 2008). Many management and training practices converge around the riding of horses. Ödberg (1987a), Ödberg and Bouissou (1999), and McLean and McGreevy (2010) speculate that the way a horse is ridden could cause chronic stress to the animal. In addition, Mills et al. (2002) reported that stereotypic behaviours were prevalent among 2-yearold Thoroughbred horses and linked it to the breaking in process. Therefore, handling and riding style merit investigation alongside other management factors for their association with problem behaviours. Normando et al. (2002) found that riding style is associated with different prevalences of problem behaviours, especially stereotypies, but they were not able to assess whether such differences were due to the riding style per se, or to different management, breed, etc. factors. Teasing apart the effects of these various factors from that of riding style is important not only to establish any role of riding style, but also to more clearly discern the relative importance of other factors, including characteristics of the horse (Luescher et al., 1998; Munoz et al., 2009) such as sex, age, and breed (Redbo et al., 1998; Albright et al., 2009), reactivity (Bachmann et al., 2003), mother s position in the herd hierarchy (Waters et al., 2002), a mare s reproductive status (Benhajali et al., 2010), and genetic factors (Albright et al., 2009; Hosoda, 1950; Luescher et al., 1998; Vecchiotti and Galanti, 1986). The current study employed an epidemiological approach to assess co-occurrences of several managementrelated factors and characteristics of horses with behavioural problems. Of particular interest are whether various management practices, stabling conditions, and breed compositions independently contribute to differences in problem behaviour between horses ridden in different styles. Although an association does not necessarily imply causation, epidemiological studies such as this provide a naturalistic approach that can identify the extent to which a rather wide range of factors are linked to the prevalence of problem behaviours among animals; they can help both prioritize factors for future research and guide management until causal mechanisms can be better established. 2. Materials and methods The study was conducted in two phases. Horses involved in phase 1 were not involved in phase 2. The methods employed in this study agree with respective national regulations on animal welfare Animals Phase 1 Phase 1 included all kinds of sport horses, except those exclusively used for racing. It studied 346 horses with caretakers/horse owners in Italian-speaking areas (303 across Italy and 43 in the Canton Ticino, Switzerland). Apart from one stable owner who did not allow the experimenter to contact the horse owners in his yard, all respondents who were contacted volunteered to complete the survey Phase 2 Phase 2 concerned 101 pure-bred Arabian horses, all stabled in Italy. All of the owners who were contacted completed the survey Questionnaire Phase 1 A questionnaire was personally administered to horse owners by one of the authors. Owners received one questionnaire per horse they owned because, unlike flat racing horses, saddle horses can have very different management and training schedules even when they share the same yard and are of the same age. Owners of any kind of horses were eligible, except those whose horses were exclusively used for racing. The questionnaire consisted of 4 sections, measuring domains that research (e.g., McGreevy et al., 1995a,b; Redbo et al., 1998) indicated may be associated with behavioural problems in horses:

3 188 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) characteristics of the horse (e.g., age, gender, reproductive status, breed, health problems, age at and method of weaning), 2. training and working schedule (e.g., riding style, discipline, changes in riding style or discipline during lifetime, hours of work a week, which kind of work, age at breaking in, number of people riding the horse), 3. management (e.g., stabling, bedding, hours/week in a paddock or field, contact with other horses, diet, number of people taking care of the horse), and 4. the horse s behaviour (including stereotypies and other problem behaviours such as aggression 1 towards people, other horses, and other animals; problems when ridden or transported; and whether the horse is easy to groom and handle). The riding/working styles included were: English, Western, driven, and other. In Italian speaking countries, English riding style denotes a riding style in which a light saddle with no horn and metal stirrups hung on narrow straps is used, reins are usually held one in each hand, there is a straight line in the rein between the hand and the mouthpiece, and rein aids (aids being the stimuli given to the horse) in changing direction are mainly through increased tension in the rein of the side to which the horse is to go and decreased tension in the other (even though, ideally, the horse should be trained to obey weight shifts in the saddle). Western riding style signifies a riding style in which a heavy saddle with a horn and stirrups hung on wide straps is used, reins are mainly both held in the same hand and form a slack loop between hand and mouthpiece, and the rein aids in changing direction are mainly through a touch of the rein on the neck of the horse opposite to the direction in which the horse is to go, as the hand goes forward and to the intended side. Poll-flexion is not usually asked in Western riding whereas it is in English style. Examples of English style disciplines are show jumping and dressage; examples of Western style disciplines are team roping and cutting. On the other hand, when a horse is driven usually there is nobody sitting on its back so no saddle is used and the horse is lead from a vehicle, which it pulls, using long reins. It is important to note that within a given riding style, the way horses are schooled and aids are given can be very different (e.g., in lightness) and thus have different effects. For example, there is considerable difference within the English style between the rather a coercive riding style that is all too often seen nowadays and the unconstrained way horses are made supple according to old academic principles as settled in the 18th century (Ödberg and Bouissou, 1999). 1 Wood chewing was defined as when a horse chews on any fittings made out of wood or wooden material without swallowing air. Although the authors are well aware that there is no scientific consensus on whether wood chewing is indeed a stereotypy, it was included among the stereotypic behaviours because many horse people in Italy consider this behaviour to be a stereotypy. The stereotypies included in the questionnaire were wood chewing 2, crib-biting 3, wind sucking 4, stall walking 5 and weaving 6 ; an additional item asked respondents to describe any other problem behaviours the horse presented apart from those already listed. If the horse for which the questionnaire was completed presented behavioural problem, the respondent was asked whether it was being managed differently now than when the behavioural problem first developed. This was done in order to take into account the tendency of stereotypies to emancipate (becoming independent from causal factor over time) (Cooper et al., 1996) and the fact that postnatal environment can influence predispositions in later life (Ödberg, 1987b). This final section also assessed whether horses related to the one for which the questionnaire was completed displayed stereotypies. Most of the items were responded to through forcedchoice, multiple choices responses (e.g., The horse is stabled: (a) single loose box stall; (b) tie stall, (c) always free in a field/paddock with a shelter; (d) always free in a field/paddock without a shelter, (e) single loose box stall with free access to a paddock, (f) other (specify: ) ), and binary choice responses (e.g., Was the horse ridden differently when the problem developed? (a) Yes, (b) No ); open ended questions were also included when necessary (e.g., Breed of the horse? ). In phase 1, the questionnaire was either given to the owner to be completed (206 questionnaires; 60%), or the owner was interviewed by the researcher (140 cases; 40%), depending on preference of the owner. In the former case, a written explanation of the behavioural terms used in the questionnaire was attached to the questionnaire itself, whereas in the latter the experimenter always gave the necessary behavioural explanations in the same way for the same term and in a way that was as similar to the written explanations as possible. In 81 of the 346 cases (23.3%), one of the researchers was able to observe the horses for which she was going to interview the owner in their loose box stall for 20 min prior to interviewing their owners. In these cases, the experimenter registered housing conditions as well as the occurrence of stereotypies and other box problems displayed/evinced during the visit with a one/zero recording method. This was done in an attempt to verify whether there was correspondence between what was declared by owners regarding the 2 Aggression was defined as overt behaviour involving intent to inflict noxious stimulation or to behave destructively towards another organism (e.g. bite, bite threat, kick, and kick threat). 3 Crib biting was defined as when a horse bends the neck, tenses the muscle on the underside of its neck while opening the mouth and with the neck muscles forces air in the oesophagus while resting its upper front teeth against any surface. 4 Wind sucking was defined as when a horse bends the neck, tenses the muscle on the underside of its neck while opening the mouth and with the neck muscles forces air in the oesophagus without supporting the teeth on any solid material. 5 Stall or box walking is when a horse is walking round and round in the box in the same direction, in alternating directions or in a 8 shaped pathway. The behaviour is repeated regularly and in an invariant manner. 6 Weaving was defined as a horse moving its weight from foreleg to foreleg and swinging its head from side to side while standing in the same place. The behaviour is repeated regularly and in an invariant manner.

4 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) behaviour of their horses and what was directly observable. The researcher and owner agreed on 80 of these 81 cases; in one case, the researcher only saw the results and not the behaviour itself, but the inferred behaviour corresponded with the owner s description Phase 2 A modified version of the questionnaire used in phase 1 was administered to the owners of pure-bred Arabian horses. The questionnaire primarily differed from phase 1 in that it now substituted show-jumping with endurance within the main use of horse item and replaced simple yes/no choices for questions such as Are there other horses in the paddock? with the introduction of more graded responses options such as yes, sometimes and no, but it can see other horses in nearby paddocks. The questionnaire was always handed directly to the owner to be completed. A total of 102 questionnaires were collected. Of these, one was discarded since none of the behaviour section questions were answered Statistical analysis For both phases, inferential analyses were conducted in two stages. First, each individual predictor variable was tested for a significant relationship with each of the abnormal behaviours. Second, all predictor variables regardless of their significance in the univariate analyses were entered into linear models to determine the subset of variables that these data indicate best predict whether or not a horse would display a given behavioural problem. All variables were tested in the multivariate analyses to factor out the effects of the variables and to allow for tests of previously non-significant variables becoming significant in light of other variables Univariate analyses Normality was assessed using Kolmogorov Smirnov tests, and homogeneity of variances using F-tests. For nominal variables, chi-squared tests and Fisher s exact tests were used to evaluate whether there were differences in the reported behaviours of the horses between questionnaires completed directly by the owner with those completed through interviews questionnaires. These tests were also used to assess the prevalence of various behaviours vis-à-vis other factors in univariate analyses. For 2 2 contingency tables, Yates-corrected chi-squared tests were used if no cell counts were less than six; two-tailed Fisher s exact tests were computed to obtain non-approximate if conservative probabilities if one or more of the cells in 2 2 tables contained values lower than six. t-tests were used when the dependant variables were interval- or ratio-level (e.g., age of the horses in English and Western ridden individuals). As the owner perceptions often dictate the success of the owner horse relationship, a very general variable behavioural complaint was also created, in order to assess whether owners had any behavioural complaints regarding their horses irrespective of what the complaint actually was. However, it is clear that the different problems listed in the questionnaire can have a completely different aetiology and meaning Multivariate analyses Although the individual effects of the various factors are important, it is also informative to assess which combinations of the factors are best able to predict the various problem behaviours. Therefore, linear discriminate analyses were conducted to find the best combination of predictor variables categorize horses into either displaying or not displaying each given problem behaviour. These multivariate analyses therefore expand upon the more sensitive, but less robust, univariate analyses (Varmuza and Filzmoser, 2009). For all models, predictor variables were entered in a forward stepwise fashion after being coded as interval scores with more deleterious responses (i.e., those associated with problem behaviours) given higher values. At each step, the variable with the highest F-score with a corresponding p-value lower than the minimal for entry (.05) was added; steps continued until no variables F-scores produced a p-value lower than.05. At any step, a previously entered variable was dropped if its F-score produced a p-value that rose above.10, the maximum retention value (e.g., due to covariance with another entered variable). Data were analysed with SPSS and Sigma-Stat. Statpages.org was used to compute Fisher s exact tests. Analyses in phase 2 paralleled those conducted in phase 1: Normality was assessed using Kolmogorov Smirnov tests and homogeneity of variances using F-tests; chisquared and Fisher s exact tests were used to compare prevalence, and t-tests were used to analyse relationships with interval or ratio data (e.g., age at weaning or age at breaking in). For categorical problem behaviours, stepwise discriminant analyses tested which variables significantly contribute to models predicting whether or not horses displayed the various problem behaviours. 3. Results 3.1. Phase Descriptive statistics and univariate results The data for all questionnaires were pooled since there were no significant differences in the responses to items collected through questionnaires completed directly by the owner and to items where the questionnaires were completed through researcher interviews (lowest p = for all 2 and Fisher s exact tests). Horses involved in phase 1 (35 stallions, 142 mares, 166 geldings, 3 gender unknown) were aged from 7 months to 31 years, with a mean age of years, SD = Tables 1 4 summarise the prevalence of responses to any undesirable behaviours among both the saddle (phase 1) and Arabian (phase 2) horses based on the various characteristics of the horses or their management. Horses said to have restrictive stabling were more often said to show locomotion stereotypies (p = 0.02) than horses without restrictive stabling. For the purpose of this study, stabling was considered restrictive when horses had no free access to a paddock/field and were taken to it less

5 190 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) Table 1 Means (and standard deviations) for relevant items when predicting whether horses displayed any undesirable behaviours for horses in both phases. Phase 1: Saddle horses Phase 2: Arabian horses Displayed any undesirable behaviours? No Yes No Yes Age in years a 1.1 (0.55) 1.2 (0.54) 8.5 (4.6) 10.2 (4.4) Age weaned 5.5 (1.5) 5.8 (1.9) Age broken in 2.8 (0.44) 2.7 (0.45) Weekly hours stabled a 22.2 (40.6) 39.6 (59.5) 10.9 (4.2) 11.6 (10.6) Weekly hours ridden a 17.9 (5.1) 16.3 (7.3) 2.9 (1.3) 1.1 (0.55) Weekly hours worked b 6.0 (5.2) 5.4 (3.5) 73.3 (26.0) 78.0 (83.3) N Notes: Item not assessed among saddle horses. a When entered into discriminant analyses, the values of these variables were divided by 10 to transform their means and standard deviations into values similar to other variables in the model. b When entered into discriminant analyses, the values of this variable were divided by 100 to transform their means and standard deviations into values similar to other variables in the model. Table 2 Phase 1 and 2 response frequencies for general items. Phase 1: Saddle horses Phase 2: Arabian horses Displayed any undesirable behaviours? No Yes No Yes Item Response N % N % N % N % Country Italy Switzerland Missing Gender Stallion Mare Gelding Missing than 6 h a day. Horses primarily ridden in the English style were more likely to live under restrictive stabling conditions than horses primarily ridden with other styles (Yates corrected 2 = 14.58; p < 0.001). Oral and locomotor stereotypies were more prevalent among horses from both phases that experienced the combination of restrictive stabling and English riding than with either condition alone or with neither condition ( 2 3 = 16.3, p = and 2 3 = 8.3, p = 0.04, respectively). In addition, being at paddock with other horses (but not being at paddock alone) was associated with a lower prevalence of aggression towards people (p = 0.02). The reported prevalences of oral and locomotor stereotypies were not influenced by the kind of bedding (straw vs. Table 3 Phase 1 and 2 response frequencies for horse activity items. Phase 1: Saddle horses Phase 2: Arabian horses Displayed any undesirable behaviours? No Yes No Yes Item Response N % N % N % N % Does horse work? Works Does not work Missing Main style currently ridden English Western Driven/draft Other/mix Does not work Missing Main use of horse Show jumping Endurance Hacking Riding lessons Driven Cutting Other/mix Does not work Missing

6 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) Table 4 Phase 1 and 2 response frequencies for care and housing items. Phase 1: Saddle horses Phase 2: Arabian horses Displayed any undesirable behaviours? No Yes No Yes Item Response N % N % N % N % Stabling situation Single loose box stall Box plus free paddock access Field plus shelter/box and paddock Other Missing Bedding type Straw Shavings Other Missing Restricted housing? Restricted Non-restricted Missing Are other horses in the same paddock/field Others present yes always yes sometimes no, but they can see other horses in paddocks nearby No other horses Missing Cannot see other horses Can see Cannot see Missing Horse given food ad libitum? Food ad lib Food not ad lib Missing Weaning method Gradual Abrupt with foals in group paddock Abrupt with foals in group inside Abrupt with foals alone in box stalls Other Missing other) or by the number of meals (up to two vs. more than two; lowest p = 0.56 for 2 or Fisher s exact tests). However, horses denied hay ad libitum were more likely to chew wood (p = 0.02) than those allowed hay ad libitum. The majority of the respondents knew nothing about their horses lineage (i.e., their sires, dams, or siblings) or youth, having acquired them as adults without being provided with this historical information. Therefore, analyses could not be meaningfully conducted for the two weaningrelated items (age at weaning and type of weaning), for the item concerning age at breaking, or for the genetic relatedness of the horses. Horses that were ridden mainly or exclusively in the English style were reported to show stereotypies more often than horses ridden in any other style (p < ). One English ridden horse was said to have developed its stereotypic behaviour before being trained for English riding, so the analysis was repeated allowing for this, but the results did not change (p = ). Regarding individual stereotypies, horses that were ridden mainly or exclusively in the English style had both more oral stereotypies (p = 0.001) and more locomotion stereotypies (p = 0.008) than horses ridden in any other style. A further analysis was carried out considering only horses whose discipline was hacking because it is possible to practice this discipline through riding either English or Western style; the same is not true, for example, for show jumping or team roping. This eliminated any possible confound from discipline practices. Hacking horses ridden English style were significantly more often reported to have some form of stereotypy than hacking horses ridden Western style (p = 0.03). It is worth noting that in 80 of 81 (98.8%) cases in which horses were observed before the interview or collection of the survey (according to owners, 15 English ridden problem horses, 23 English ridden problem-free horses, 6 Western ridden problem horses, 37 Western ridden problem-free horses), behaviour that was declared in the questionnaire corresponded to what was recorded by the experimenter. In one case the horse was said to pace in the stall, but the actual behaviour was not seen. However an unmistakable circular trace in the bedding material all around the perimeter of the stall attested to what the owner stated. English style ridden horses were reported to have more problems when transported (p = 0.001), and to be more likely to present more than one behavioural problem (p < 0.001). Show jumpers were found to show aggression towards people more often than other English ridden horses (p = 0.03), but did not differ in stereotypies (both oral

7 192 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) and locomotion), problems during work, other problems when stabled (besides stereotypies), problems when transported, or displaying more than one problem behaviour Another interesting finding about riding style which did not directly concern behavioural problems, but which could be interesting from a welfare point of view, was that horses which had been ridden exclusively using English style all their working life were more often reported to have locomotive apparatus health problems (i.e., lameness), p = 0.04, than those that had been ridden exclusively using Western style all their working life. However, Western style ridden horses in the sample were significantly younger than English style ridden ones (median of 7 vs. 11 years, range 2 30 vs years; z = 6.54, p < 0.001), as the former begin training at a younger age, and this could have contributed to this difference. Note that age, however, was not significant in differentiating problem horses from problem free ones. No gender differences were found among any of the problem behaviours (lowest p = for 2 or Fisher s exact tests). No differences due to country were found in stereotypies (oral or locomotor), problems when worked or transported, non-stereotypic stable problems, aggression, or other problems (lowest p = for 2 or Fisher s exact tests). Wood chewing was more frequent among the Swiss horses (p = 0.049), while there was a non-significant tendency for having more complaints about Italian horses (p = 0.064) Discriminant analysis Tables 1 4 present the variables considered for entry into the initial model along with statistics for those horses that the owners indicated displayed any or no undesirable behaviours. The final model was significant ( 2 4 = 47.11, p < 0.000). The eigenvalue for the final model was 0.186, and Wilk s lambda for the final model, which represents the proportion of variance in the outcome variable unaccounted for by the model, was Using separate covariance matrices did not aid the model structure. The resulting model correctly classified 74 (72.5%) of the 102 horses with undesirable behaviours (when a given case was excluded from the model) and 160 (65.6%) of the 244 horses without any undesirable behaviours; overall, twothirds (67.6%) of the cases were classified correctly by the model. The following factors were significant predictors of abnormal behaviours: (1) English riding style, (2) country (Switzerland more than Italy), (3) fewer hours/week access to a paddock, and (4) younger age. Therefore, knowing the main riding style, country, hours/week a horse is kept in a paddock, and its age is sufficient to determine whether or not a horse in this sample will evince any undesirable behaviours 67.6% of the time. Horses ridden in the English style tended to be older than those ridden in the Western (see univariate analyses, above), but riding style remained significant even when age was factored out. Although country was predictive, it is perhaps the least informative for those wishing to use these data as guides. A model that only included main riding style, hours/week paddocked, and age correctly predicted whether a horse would display any undesirable behaviour 62.0% of the time in this sample. Table 5 summarizes the models computed to determine the nominal problem outcome variables, including whether the horse displayed any problem behaviours for comparison. Each row presents the statistics for the final overall model predicting the given outcome variable on the left; on the right are the variables retained in the final model and their respective discriminant function coefficients. This table confirms the influence of riding style: eight of the ten final models predicting a given problem behaviour included riding style; four included riding style as the sole significant predictor of the given problem behaviour, including three of stereotypic behaviours. Note, however, that the models also indicate that predictor variables generally predict the absence of a problem behaviour more reliably than its presence. Although on average the models correctly diagnosed a horse based on a given set of predictor variables 65.9% of the time, they correctly diagnose the absence of a problem behaviour (mean percent correct of 73.7%) more often than they correctly diagnosed the presence of a problem behaviour (mean percent correct of 65.0%). Stereotypic behaviours tended to produce more lopsided diagnoses Predicting total number of problem behaviours An ANOVA testing the effects of all possible predictors on the total number of problem behaviours (a ratio variable) was significant (F 27,250 = 2.70, MSE = 0.583, 2 = 0.226, p < 0.000), although the intercept was not (F 1,250 > 1). Only the main style ridden (English vs. other styles, F 1,250 = 6.22, p < 0.000) and country (Switzerland more than Italy, F 1,250 = 6.32, p = 0.013) were significant predictors of higher incidence of abnormal behaviours; no other variables reached significance (largest F 1,250 = 3.03, p = 0.083, n.s.). Consistent with the results for other outcome variables, riding style strongly affects the total number of problem behaviours among these saddle horses. Given the relative infrequency of a given horse demonstrating multiple problem behaviours, the correlations between different types of problem behaviours were small. This also indicates that models correlating multiple outcome variables (viz., MANOVAs) are redundant Phase Descriptive statistics and univariate results Horses involved in phase 2 were aged from 1 to 23 years (mean ± S.D. = 8.88 ± 4.69 years). They were 43 (42.6%) mares, 33 (32.7%) geldings, and 25 (24.7%) stallions. The main riding/working styles for the Arabian horses were: English riding style for 52 (51.5%) horses, Western style for 37 (36.6%) horses, other styles (e.g., driving, vaulting, equal mix of other styles) for 3 (3.0%) horses, and not working for 9 (8.9%) horses. As summarized in Table 6, the prevalence of problem behaviours varied greatly between the saddle (phase 1) and Arabian horses (phase 2). Except for stereotypies, wood chewing, and trailering problems, Arabian horses were reported to display every type of problem behaviour investigated in this study at a much higher frequency than the saddle horses (all ps 0.03 for 2 s). However, Arabian horses were reported to be less aggres-

8 Table 5 Discriminant analysis results for all nominal problem outcome variables for saddle horse data. Predictor variables are expressed in terms of the most deleterious level(s); e.g., English Riding Style indicates that horses ridden in the English style were more likely to evince a given problem than any other style. Final model Percent correct classifications Model variables (with standardized canonical discriminant function coefficients) Outcome variable 2 df p Eigen-value Did not display Displayed any problem behaviours? Displayed behaviour Total correct English riding style (0.80) Wood chewing More hrs/wk stabled (0.85) Other problems Not given food ad lib (0.55) Shows multiple problems? More hrs/wk paddocked ( 1.2) Trailering problems English riding style (0.99) Aggression towards people English riding style (0.80) Displays stereotypies? English riding style (1.0) Oral stereotypies? English riding style (1.0) Problems when worked? English riding style (1.0) Locomotion stereotypies? Show jumping v. riding lessons/no work (1.0) First Second Third Fourth Switzerland (0.66) Fewer Hrs/Wk in paddock or field ( 0.61) Younger age ( 0.48) No other horses in paddock (0.44) More hrs/wk stabled Bedding type (0.39) Male v. female/gelding (0.48) ( 0.37) Restricted housing (0.80) More hrs/wk stabled (0.67) No other horses in paddock ( 0.74) English riding style (0.74) Cannot see other horses (0.47) S. Normando et al. / Applied Animal Behaviour Science 133 (2011)

9 194 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) Table 6 Frequency of problem behaviours for both Saddle and Arabian horses. Problem variable Arabian horse data Saddle horse data Fisher s exact test or Yates corrected chi-squared Higher prevalence in Any undesirable behaviour? Yes = Arabians No p = Missing 1 0 Problems when worked? Yes = Arabians No p = Missing Problems in stall besides stereotypies? Yes = Arabians No p < Missing 2 1 Wood chewing? Yes 2 12 No p = Missing 0 1 Aggression towards people? Yes 0 19 Saddle horses No p = Missing 3 1 Trailering problems? Yes = No p = Missing Other problems? Yes = Arabians No p = Missing 2 2 More than one problem? Yes = No p = Missing 1 1 Show stereotypies? Yes = No p = Missing 0 1 Oral stereotypies? Yes 3 24 No p = Missing 0 1 Locomotion stereotypies? Yes = No p = Missing 0 1 sive towards people (p = 0.01) than were the phase 1 saddle horses. On the whole Arabian horses were less frequently reported to be kept in restricted stabling that saddle horses (Yates corrected 2 = 70.49; p < 0.001; median hours/week at paddock being 80 vs. 10). Data on weaning were only available for 58 (57.4%) of the 101 Arabian horses. There were no significant differences between the frequencies of stereotypies and non-stereotypic problem behaviours between the gradually weaned and abruptly weaned Arabian horses (p = 0.112). Nor were any significant differences found among the Arabian horses with this analysis in age at weaning and age at first breaking in (largest F 1,70 = 1.05, MSE = , p = 0.309). The prevalence of oral stereotypies was not affected by riding style among Arabian horses. Further analyses considering only Arabian horses whose discipline was hacking found no significant differences among prevalence of any stereotypic behaviour between Arabian horses ridden English riding style, and those ridden in a different style, i.e., Western riding style, driving, other styles or no job (p = 0.260) Discriminant analysis The variables presented in Tables 1 and 2 present those available for Arabian horses that were analysed via discriminant analyses. These variables were entered into a series of discriminant analysis to determine the best data-driven models for predicting given problem behaviours among the Arabian horses. As was true with phase 1 data, using separate covariance matrices did not aid the models structures. Table 5 summarizes these models results. The first row provides the model statistics and final set of predictive variables for responses to the prompt Does your horse display any problem behaviour. Note that the questions asked about the Arabian horses conditions differed slightly from those asked of saddle horse conditions; data for the Arabian horses were also less complete than for saddle horses. Therefore, different (and fewer) analyses were possible for

10 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) the data on Arabian horses conditions. Horses reported to be ridden for fewer hours per week were significantly less likely to display a given abnormal behaviour in three of the five models (all ps.05); these analyses corroborate the general influence of riding on horses behaviours. The age at which the horse is broken in, being kept in restricted housing, and main use of horse were also generally predictive factors (Table 7) Predicting total number of problem behaviours An ANOVA testing the effects of all possible predictors on the total number of problem behaviours (a ratio variable) was conducted for the 22 Arabian horse (21.78%) for which all data (no missing answers) were available. This model (F 11,22 = 9.76, MSE = 0.045, adjusted R 2 =.814, p < 0.000) and intercept (F 1,22 = 29.8, p = ) were both significant. Significant predictors of fewer total abnormal behaviours were being loose in a single box stable (F 3,22 = 11.91, ˇ = 1.079, p = 0.005), being able to see other horses (F 1,22 = 18.50, ˇ = 0.739, p = 0.001), given ad lib food (F 1,22 = 25.33, ˇ = 1.324, p = ), gradual and/or group weaning (F 4,22 = 47.51, ˇ = 2.820, p < 0.000), fewer hours per week ridden (F 1,22 = 29.48, ˇ = 4.257, p = ), and fewer hours per week stabled (F 1,22 = 19.27, ˇ = 2.02, p = 0.001). 4. Discussion Our results support the relationship of managementrelated factors with stereotypies and other problem behaviours. The speculations about riding style were borne out: problem behaviours were more common among saddle horses ridden in the English style than those ridden in any other style. This finding was rather robust, appearing when assessing rather different types of behaviours and even when other factors were considered (in multivariate analyses). Being ridden in the English style was the strongest predictor of stereotypies especially oral stereotypies among saddle horses. This agrees with previous work (Normando et al., 2002), and also affected the prevalence of lameness. Riding style s effect on stereotypies is not likely due to the associated restrictive stabling, which occurs more frequently among English ridden saddle horses, because restrictive stabling was found to be linked to a higher prevalence of locomotion, but not with oral stereotypies. Moreover, both riding style and restrictive housing appeared significant in some of the same multivariate analyses. However there was a effect of the combination of restrictive stabling and English riding on both oral and locomotion stereotypies suggesting that one condition could exacerbate the effect of the other. The English riding style might be more of a problem for horses, because it uses more leg-to-body and handto-mouth contact, which, when the rider is inexperienced, could lead to more incoherent signalling. Although the number of hours per week ridden predicted nearly all problem behaviours among Arabian horses, riding style did not. This could be because few of the Arabian horses in the sample were housed restrictively so that the non-restrictive stabling conditions could have Table 7 Discriminant analysis results for all nominal problem outcome variables for Arabian horse data. Predictor variables are expressed in terms of the most deleterious level(s); e.g., Endurance v. Not Working indicates that horses employed primary for endurance training were more likely to evince problems in their stalls than horses not worked. Final model Percent correct classifications Model variables (with standardized canonical discriminant function coefficients) First Second Third Fourth Fifth Total correct Displayed behaviour Outcome variable 2 df p Eigen-value Did not display Later age broken in (0.93) More hrs/wk ridden (1.27) Displayed any problem behaviours More hrs/wk worked (0.77) Hacking v. other/mix (1.20) Problems when worked? More hrs/wk ridden (0.78) Later age broken in (1.35) More hrs/wk stabled (1.84) Endurance v. not working (3.04) Restricted housing (4.03) Problems in stall other than stereotypies Trailering problems More hrs/wk ridden (1.0) Other/multiple More restricted problems housing (1.0)

11 196 S. Normando et al. / Applied Animal Behaviour Science 133 (2011) buffered the effects of English riding style on stereotypies. Or it maybe that breed plays a role in the prevalence of stereotypies among English and Western style ridden horses, as the breeds involved in Western style riding tend to differ from those involved in English style. Albright et al. (2009) found that Thoroughbreds were three times more likely to display crib biting than Quarter Horses, the latter being more represented among Western style ridden horses. However, the influence of breed on stereotypy prevalence is controversial. On the one hand, Luesher et al. (1998) found breed to be important, with Thoroughbreds showing more cribbing and weaving and Arabians showing more stall walking; Redbo et al. (1998) found higher prevalence in Thoroughbreds that are in trotters (although linking this to differences in management); and Christie et al. (2006) found that horse type (drafts and miniatures) reduced the risk of showing oral stereotypies. On the other hand, Flannigan and Stookey (2002) found no difference in stereotypies between light and draft mares, and Parker et al. (2008) found no breed effect on the prevalence of stereotypies. Factors related to freedom of movement (restricted housing and hours paddocked or stabled), and access to other horses (being paddocked with other horses or being able to see other horses) were also commonly associated with problems behaviours in both phases. These aspects of the horses conditions are those which deviate more from the natural environment to which horses are adapted. Whatever the underlying mechanisms, this study underscores the importance of management-related factors already stressed in several studies, such as Bachmann et al. (2003) who found that horses denied daily access to pasture were at a higher risk of crib-biting, weaving, and box walking; or Christie et al. (2006) who found that more hours at pasture was associated with a decreased risk of showing oral stereotypies. Although straw bedding has been found to reduce the risk of problems (Christie et al., 2006; McGreevy et al., 1995a), we found no significant relationship between bedding material and stereotypies. We did, however, find it is a risk factor for stable problems other than stereotypies. In addition, others found that weaning practices affect the presence of stereotypies. Parker et al. (2008), for example, found that restrictive stabling both pre- and postweaning corresponded to an increased risk of stereotypies and that formal weaning resulted in more stereotypies than natural weaning. Stalled weanlings have been found to have a higher prevalence of stereotypies (Waters et al., 2002) and more aberrant behaviours (i.e., pawing, licking/biting/kicking shed, or stall wall, Heleski et al., 2002) than paddocked weanlings. We did not find weaning methods predictive. However, we were not able to collect detailed or complete data on weaning histories, so the practical power of our analyses cannot be considered high. Both current (Bachmann et al., 2003; McGreevy et al., 1995a; Redbo et al., 1998) and weaning (Parker et al., 2008; Waters et al., 2002) diet has also been associated with an increased risk of stereotypies. In general, an increased quantity of roughage decreases the risk of stereotypies. Bachmann et al. (2003) found that the probability of displaying crib-biting, weaving, or box walking were higher when horses were fed 4 times/day compared to those fed more often or ad libitum. Cooper et al. (2005) reported that increasing the number of meals decreased oral stereotypies, but increased weaving and nodding prior to feeding. Their control group also showed more weaving, nodding, and oral stereotypies while their yard-mates received more meals. We found that horses denied hay ad libitum were more likely to engage in wood-chewing, consistent with Redbo et al. (1998) who found more roughage was linked to a decreased prevalence of woodchewing. However, we did not find that the number of meals was associated with the presence of any problem behaviours. While the effects of management on stereotypy prevalence have received much scientific attention, the work the horse performs has not. Although McGreevy et al. (1995b) reported a lower prevalence of stereotypies among horses engaged in endurance horses compared with dressage and eventing, they suggested this may be due to management differences since endurance horses were confined to their stables less. More indirectly, Redbo et al. (1998) found that the number of horses per trainer significantly predicted stereotypies prevalence, and Christie et al. (2006) found that the number of hours a horse worked was linked to weaving. In the present study, the number of hours an Arabian horse was worked or ridden were risk factors for the presence of behavioural problems, non-stereotypic stall problems, and problem when worked but not for stereotypies and not among saddle horses. It is interesting to note that, in the current study, age at breaking in (beginning to work) was found to be a risk factor for Arabian horses developing non-stereotypic stable problems. Hausberger et al. (2009) found that the kind of equestrian discipline a horse was involved in (show jumping, eventing, dressage, etc.) was related to both the prevalence and the type of stereotypies displayed in similarly housed French Saddlebred horses that were all ridden the same length of time, independent of management practices. In phase 1, we also found that a horse s discipline predicts locomotion stereotypies, and that show jumpers were more aggressive towards people than other horses ridden English style. We also found that younger horses displayed more problem behaviours, but not more stereotypies. Mills et al. (2002) found a higher prevalence of their behaviours in two-year-old than either younger or older Thoroughbreds, whereas Luesher et al. (1998) found that the risk of crib-biting and weaving increased with age. In our study, gender was a significant risk factor for the presence of non-stereotypic stable behavioural problems, but not for stereotypies, whereas a higher prevalence of stereotypies/abnormal behaviours was found among mares (Mills et al., 2002), geldings (Luesher et al., 1998; Mills et al., 2002; Ahmadinejad and Habibi, 2005) or stallions (Luescher et al., 1998; Ahmadinejad and Habibi, 2005). Although the current analyses help tease apart the relative importance of various factors, it must be remembered that the individual factors themselves are not always unidimensional. Riding style, for example, connotes both management-related factors (housing, working hours,