Abstract: Selegiline ([R]-[-]N,alpha-dimethyl-N-2- propynylphenethylamine or l-deprenyl), an irreversible inhibitor of monoamine oxidase, is a classic antidyskinetic and antiparkinsonian agent widely used in human medicine both as monotherapy and as an adjunct to levodopa therapy. Selegiline is classified by the Association of Racing Commissioners International (ARCI) as a class 2 agent, and is considered to have high abuse potential in racing horses. A highly sensitive LC/MS/MS quantitative analytical method has been developed for selegiline and its potential metabolites amphetamine and methamphetamine using commercially available deuterated analogs of these compounds as internal standards. After administering 40 mg of selegiline orally to two horses, relatively low (<60 ng/ml) concentrations of parent selegiline, amphetamine, and methamphetamine were recovered in urine samples. However, relatively high urinary concentrations of another selegiline metabolite were found, tentatively identified as N- desmethylselegiline. This metabolite was synthesized and found to be indistinguishable from the new metabolite recovered from horse urine, thereby confirming the chemical identity of the equine metabolite. Additionally, analysis of urine samples from four horses dosed with 50 mg of selegiline confirmed that N-desmethylselegiline is the major urinary metabolite of selegiline in horses. In related behavior studies, p.o. and i.v. administration of 30 mg of selegiline produced no significant changes in either locomotor activities or heart rates.

Abstract: Resistance in the horse to trailer loading is a common source of stress and injury to horses and their handlers. The objective of this study was to determine whether nonaversive training based on the Tellington-Touch Equine Awareness Method (TTEAM; Tellington-Jones &Bruns, 1988) would decrease loading time and reduce stress during loading for horses with a history of reluctance to load. Ten horses described by their owners as “problem loaders” were subjected to pretraining and posttraining assessments of loading. Each assessment involved two 7-min loading attempts during which heart rate and saliva cortisol were measured. The training consisted of six 30-min sessions over a 2-week period during which the horse and owner participated in basic leading exercises with obstacles simulating aspects of trailering. Assessment showed heart rate and saliva cortisol increased significantly during loading as compared to baseline (p <.001 and p <.05, respectively). Reassessment after training showed a decrease in loading time (p <.02), reduced heart rate during loading (p <.002), and reduced saliva cortisol as compared to pretraining assessments. Seven “good loaders” also were subject to loading assessment for physiological comparison. Increases in heart rate during loading were significantly higher in the good loaders (p <.001). Nonaversive training simulating aspects of loading may effectively reduce loading time and stress during loading for horses with a history of resistance to trailer loading.

Abstract: REASONS FOR PERFORMING STUDY: Studies on the prevalence of behavioural disorders in horses and on associated risk factors have revealed inconsistent results. There are many studies on the neuropharmacological, surgical or mechanical therapy of stereotypies, but little is known about their causation. OBJECTIVES: To explore risk factors associated with the occurrence of behavioural disorders in horses. METHODS: A sample of horse owners, selected randomly and representative for Switzerland, was contacted in a postal survey. Answers were provided for 622 stables (response rate 35.2%). Individual data of 2,341 horses were examined with path analysis (multivariable linear and logistic regression), and adjustment made for possible confounding effects due to age and breed. RESULTS: Out of 60 possible risk factors, 11 were associated with the outcome at the univariable level (null-hypothesis path model) and 3 factors remained after the backward logistic regression procedure. Mature Warmbloods and Thoroughbreds, assessed by the owners to be reactive, fed 4 times a day and without daily pasture, had increased odds of displaying crib-biting, weaving and box-walking. Furthermore, indirect associations of 5 factors with the outcome were identified. CONCLUSIONS: The final logistic regression model of risk factors leads to the hypotheses that causal prevention of stereotypic behaviours should be based upon housing and management conditions which allow tactile contact with other horses (e.g. mutual grooming), daily free movement (paddock or pasture), as well as the provision of high amounts of roughage but of little or no concentrates. POTENTIAL CLINICAL RELEVANCE: It is one of the aims of population medicine to prevent the development of behavioural disorders. Further research is needed to test the concluding hypotheses in experimental studies or to verify them in the context of similar observational studies.

Abstract: Thirty-six owners of seasonally headshaking horses took part in a trial to compare the effectiveness of three types of nose net, a traditional cylindrical net (full net) and two forms of larger mesh nets which cover only the nostrils and dorsorostral muzzle (half nets). Baseline data relating to the overall severity of the problem and 18 specific behaviours describing the nature of the problem were recorded on a check sheet by the owners. A within-subjects repeated measures design experiment, with each net used for a week before reassessment, was then used to assess the effect of the nets on the headshaking problem. Approximately 75 per cent of owners reported some overall improvement with each net; around 60 per cent recorded a 50 per cent or greater improvement and 30 per cent a 70 per cent or greater improvement. The nets significantly reduced the overall headshaking score and the following specific behaviours: up-and-down headshaking, nose flipping, acting as if a bee had flown up the nose, shaking at exercise, shaking when excited, shaking in bright sunlight or in windy conditions (P < 0.0001), striking at the face, shaking at night, rubbing the nose when moving, rubbing the nose on objects, sneezing, shaking in the rain and shaking indoors (P < 0.05). There was no evidence of a significant effect on side-to-side headshaking, shaking at rest or rubbing the nose when stationary, but the effect on snorting was uncertain. There were few significant differences between the nets, but the half nets were reported to be significantly better at controlling 'bee up the nose' behaviour. Horses more than 10 years old were reportedly less likely to show a 50 per cent or greater improvement in 'nose flipping' and 'headshaking at exercise.

Abstract: Temperament traits in animals may have important fitness consequences, but have received little attention from ecologists or evolutionary biologists. A few studies have linked variation in temperament with fitness, but none has measured selection on temperament traits. We estimated the strength of selection on female boldness and docility on bighorn sheep ewes, Ovis canadensis. The Ram Mountain population experienced little predation pressure during the first 25 years of study, then 2 years (1997 and 1998) of frequent predation by cougars, Puma concolor, during which adult ewe mortality almost tripled over the long-term average, to 27% a year. During years of high predation, we found moderate selection favouring bold ewes, and age-specific selection on docility. Old ewes appeared more vulnerable to predation than young ewes. In contrast, no evidence of selection on temperament traits was observed during 2 years of low predation (1996 and 1999). These results suggest predator-induced selection favouring bold and nondocile ewes. Leadership was highly correlated with age and may increase the risk of predator encounter. Leadership alone, however, could not explain the higher vulnerability of old ewes to predation. Cougar predation on bighorn sheep occurs sporadically and unpredictably, probably because individual cougars often are prey specialists. Cougar predation may have limited microevolutionary effects on temperament in bighorn sheep, because it mostly affects ewes near the end of their reproductive life span and because of potential countervailing selection on boldness and docility. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.