Master of Science in Veterinary Science / Developmental Orthopaedic Disease (DOD) describes problems affecting the limbs of young horses, including abnormal bone, joint and tendon development. DOD is responsible for major economic losses in the Thoroughbred industry. Investigation into the epidemiology of DOD in Australia and Ireland as described in this thesis has allowed valuable comparisons and recommendations to be made between the studs in these countries. The project described in this thesis commenced in 1999, with the aim to: a) Establish the incidence of DOD on a stud in Australia and to compare this with similar data for a stud in Ireland b) To determine relationships between factors affecting severity and incidence of DOD in foals with respect to the country in which they are bred and raised c) To further identify risk factor areas associated with the development of DOD Records of 1717 mares from a major stud in Ireland and another in Australia were made available. Foal weight, age of mare, condition of mare, foal sire and date of birth were monitored over two years. The occurrence of DOD was recorded against these data. The incidence of DOD was found to be higher on the stud in Australia (average 49.85%) than on the stud in Ireland (average 14%). Foal weight was found to be a significant factor affecting DOD, with heavier foals showing a proportionally higher severity of the problem. The Australian stud had a higher incidence of DOD in 2000 compared to 1999 (65.2% affected vs 32.1% in 1999), whereas the Irish stud had a lower incidence in 1999 compared to 2000 (11.8% affected vs 16.2% in 2000). The dramatic increase in the incidence of DOD in Australian foals over the 1999-2000 period is representative of the increase in a major problem in the industry, as well as greater awareness of the problem over recent years. It highlights the urgent need for further research into understanding the cause(s) of DOD. Overall recommendations arising from the study include that a large scale, long term study be undertaken in Australia. Further investigation into the nutrition of horses in Ireland and Australia would be of great usefulness in understanding DOD, as would possible genetic links. An issue requiring attention is that of developing a standard definition of the disorder. Considering the wide range of disorders which may fit under the umbrella term DOD, a clear definition is of great importance. The incidence of DOD on one large farm in Ireland was found to be currently low and stable relative to its another large stud farm in Australia. This is a significant finding as the genetic pool of the horses share similarities on both farms, particularly as stallions shuttling between hemispheres sire many foals on both farms. Thus, the data provided herein provide an excellent basis for further valuable comparative studies investigating DOD in foals with a similar genetic background but subjected to differing environmental conditions.

This thesis is concerned with equine attachment as a form of interspecies fictive kinship, in relation to the practices, social relations, and motivations of participant groups within the Canterbury thoroughbred racing industry. Exploring the interconnections between intimacy and investment, as both financial and emotional commitments, the different sectors of the industry are analyzed as actor-network assemblages in which boundaries between professional, economic, and social relations are porous. The thesis argues that the parameters of a distinct equine community are delineated through regulated forms of haptic access. Distinctions regarding those who are and are not permitted to touch horses, articulates with a regime of risk regulation, which is more broadly explored in its physical, social, financial, and emotional dimensions. Also integral to the character of this networked community of practitioners is the symbolism of naming and branding thoroughbreds, as well as the secular rituals of the auction and the race-day. Conceived as a naturalcultural phenomenon, the race is analyzed in terms of the cross-species meanings and experiences of jockeys and apprentices, who are understood as representatives of an occupational sub-culture. Finally, this thesis also explores the preponderance of women in South Island racing; charting the path by which they have successfully adopted traditionally male-dominated roles.

Master of Science in Veterinary Science / Developmental Orthopaedic Disease (DOD) describes problems affecting the limbs of young horses, including abnormal bone, joint and tendon development. DOD is responsible for major economic losses in the Thoroughbred industry. Investigation into the epidemiology of DOD in Australia and Ireland as described in this thesis has allowed valuable comparisons and recommendations to be made between the studs in these countries. The project described in this thesis commenced in 1999, with the aim to: a) Establish the incidence of DOD on a stud in Australia and to compare this with similar data for a stud in Ireland b) To determine relationships between factors affecting severity and incidence of DOD in foals with respect to the country in which they are bred and raised c) To further identify risk factor areas associated with the development of DOD Records of 1717 mares from a major stud in Ireland and another in Australia were made available. Foal weight, age of mare, condition of mare, foal sire and date of birth were monitored over two years. The occurrence of DOD was recorded against these data. The incidence of DOD was found to be higher on the stud in Australia (average 49.85%) than on the stud in Ireland (average 14%). Foal weight was found to be a significant factor affecting DOD, with heavier foals showing a proportionally higher severity of the problem. The Australian stud had a higher incidence of DOD in 2000 compared to 1999 (65.2% affected vs 32.1% in 1999), whereas the Irish stud had a lower incidence in 1999 compared to 2000 (11.8% affected vs 16.2% in 2000). The dramatic increase in the incidence of DOD in Australian foals over the 1999-2000 period is representative of the increase in a major problem in the industry, as well as greater awareness of the problem over recent years. It highlights the urgent need for further research into understanding the cause(s) of DOD. Overall recommendations arising from the study include that a large scale, long term study be undertaken in Australia. Further investigation into the nutrition of horses in Ireland and Australia would be of great usefulness in understanding DOD, as would possible genetic links. An issue requiring attention is that of developing a standard definition of the disorder. Considering the wide range of disorders which may fit under the umbrella term DOD, a clear definition is of great importance. The incidence of DOD on one large farm in Ireland was found to be currently low and stable relative to its another large stud farm in Australia. This is a significant finding as the genetic pool of the horses share similarities on both farms, particularly as stallions shuttling between hemispheres sire many foals on both farms. Thus, the data provided herein provide an excellent basis for further valuable comparative studies investigating DOD in foals with a similar genetic background but subjected to differing environmental conditions.

With a rise in concern for animal welfare, the equine world has started using positive reinforcement (R+); as such, horses often experience a combination of negative reinforcement (R-) and R+. I compared the effects of R- to a combination of positive and negative reinforcement (R-/R+) training. Horses were trained to walk across two visually discriminable liverpools (striped, Experiment 1; colored water, Experiment 2), each associated with either R- or R-/R+, and training type alternating across six days. I measured highest training criteria reached, prevalence of undesirable behaviors, salivary cortisol (pre- and post-training), time spent by the trainer in motionless human tests (pre- and post-training), and horses' preference for the two liverpools using concurrent choice. Across both experiments, I found no significant difference in the proportions of criteria reached between training types; horses engaged in mugging for longer periods of time in R-/R+ than R-; no significant difference between training types for the pre- to post-change of cortisol; a greater proportion of horses increased time spent with R-/R+ trainer than the R- trainer; and no difference between first choice in the preference test or time horses spent in proximity to the liverpool, based on the training type with which the liverpool was associated. Overall, I found few differences between R-/R+ and R-, which could be due to horses only having 30 min total training contact with either training, or my use of relatively low intensities of R- and R+. / Master of Science / The equine world has started using positive reinforcement (R+), such as providing treats. Often horses experience a combination of negative reinforcement (R-) and R+, such as having rein pressure released and being given a treat. I compared effects of R- to a combination of positive and negative reinforcement (R-/R+) training. Horses were trained to walk across two visually distinct liverpools, a 1 m X 2.7 m shallow pool, (striped, Experiment 1; colored water, Experiment 2) each associated with either R- or R-/R+, and training type alternating across six days. I measured highest training level reached, occurrence of undesirable behaviors, salivary cortisol (a measure of stress), time spent by the trainer in motionless human tests, and horses' preference for the two liverpools. Across both experiments, I found no significant difference in the proportions of criteria reached between training types; horses investigated the trainer for treats for longer durations in R-/R+ than R-; no significant difference between training types for the pre- to post-change; a greater proportion of horses increased time spent with R-/R+ trainer than R- trainer; and no difference between first choice in the preference test or time horses spent in proximity to the liverpool, based on the training type with which the liverpool was associated. Overall, I found few differences between R-/R+ and R-, which could be due to horses only having 30 min total training contact with either training, or my use of relatively low intensities of R- and R+.

A hemorragia pulmonar induzida por exercício (HPIE) é caracterizada pela presença de sangue no trato respiratório anterior e posterior, sendo considerada por muitos autores como a principal causa na redução do desempenho atlético, acarretando prejuízos econômicos significativos. Processos inflamatórios e obstrutivos das vias aéreas anteriores têm sido propostos como fatores desencadeadores da HPIE, contudo, a literatura tem sido conflitante na determinação desta correlação. O objetivo do presente estudo foi a avaliação da correlação entre HPIE e alterações das vias aéreas anteriores e traquéia em eqüinos da raça PSI que competiram no hipódromo da Cidade Jardim do Jockey Club de São Paulo no período de março de 1999 a setembro de 2005. Foram analisados 4036 laudos endoscópicos. Os exames endoscópicos foram realizados trinta minutos após corrida e por um único examinador. Dos eqüinos que participaram do estudo, 2229 foram submetidos à medicação prévia com furosemida e 1737 não foram medicados (solicitações). Os resultados obtidos com relação à incidência de HPIE no grupo dos animais medicados e não medicados foram 52,40% e 60,00% respectivamente, não havendo variação estatisticamente significativa na incidência de HPIE quanto à distribuição etária e sexo. No entanto, a incidência de grau 4 da HPIE nas fêmeas foi duas vezes maior quando comparado com os machos. De modo geral, não se observou correlação positiva entre a HPIE e alterações das vias aéreas anteriores e traquéia, a não ser nos eqüinos com deslocamento dorsal do palato mole (estatisticamente significativa) ou com neuropatia laringeana recorrente esquerda, apesar de não apresentar significado estatístico. Os eqüinos acometidos por doença inflamatória das vias aéreas não apresentaram relação com HPIE. Dentre as alterações das vias aéreas anteriores estudadas, a neuropatia laringeana recorrente esquerda e deslocamento dorsal do palato mole apresentaram correlação positiva com hemorragia pulmonar induzida por exercício, sendo que apenas para a segunda foi estatisticamente significativa. / Exercise-induced pulmonary hemorrhage (EIPH) is characterize by blood found in upper and lower respiratory tract. It is considered by many authors to have a negative effect on the athletic performance of racing horses, causing significantive economic losses. Some authors suggest that obstructive and inflammatory process breaks out HPIE, but this question hasn´t been settled so far. The aim of this study is to identify the relations between exercise-induced pulmonary hemorrhage and alterations of upper airways and trachea on Thoroughbreds racehorses that raced at the tracks of the São Paulo Jockey Club from March, 1999 to September, 2005. The endoscopic examination was made 30 minutes after the race by a single examiner, and 4036 results have been analyzed. Among these horses, 2229 took previous furosemide medication and 1737 didn´t. The results regarding the presence of EIPH were 52.40% for the first group and 60% for the second, with no significant difference related to age and sex. However, the prevalence of grade 4 EIPH among females was two times bigger than among males. No positive relation between EIPH and alterations of upper airways and trachea was observed, although in dorsal displacement of the soft palate that was statistically significantive or with recurrent laryngeal neuropathy left although no statistically significative. The horses that presented disease of upper airways didn´t any relation with EIPH. Among alterations of upper airways analyzed, the recurrent laryngeal neuropathy left and dorsal displacement of the soft palate showed positive relation with EIPH, and only the second one was statistically significative.

A hemorragia pulmonar induzida por exercício (HPIE) é caracterizada pela presença de sangue no trato respiratório anterior e posterior, sendo considerada por muitos autores como a principal causa na redução do desempenho atlético, acarretando prejuízos econômicos significativos. Processos inflamatórios e obstrutivos das vias aéreas anteriores têm sido propostos como fatores desencadeadores da HPIE, contudo, a literatura tem sido conflitante na determinação desta correlação. O objetivo do presente estudo foi a avaliação da correlação entre HPIE e alterações das vias aéreas anteriores e traquéia em eqüinos da raça PSI que competiram no hipódromo da Cidade Jardim do Jockey Club de São Paulo no período de março de 1999 a setembro de 2005. Foram analisados 4036 laudos endoscópicos. Os exames endoscópicos foram realizados trinta minutos após corrida e por um único examinador. Dos eqüinos que participaram do estudo, 2229 foram submetidos à medicação prévia com furosemida e 1737 não foram medicados (solicitações). Os resultados obtidos com relação à incidência de HPIE no grupo dos animais medicados e não medicados foram 52,40% e 60,00% respectivamente, não havendo variação estatisticamente significativa na incidência de HPIE quanto à distribuição etária e sexo. No entanto, a incidência de grau 4 da HPIE nas fêmeas foi duas vezes maior quando comparado com os machos. De modo geral, não se observou correlação positiva entre a HPIE e alterações das vias aéreas anteriores e traquéia, a não ser nos eqüinos com deslocamento dorsal do palato mole (estatisticamente significativa) ou com neuropatia laringeana recorrente esquerda, apesar de não apresentar significado estatístico. Os eqüinos acometidos por doença inflamatória das vias aéreas não apresentaram relação com HPIE. Dentre as alterações das vias aéreas anteriores estudadas, a neuropatia laringeana recorrente esquerda e deslocamento dorsal do palato mole apresentaram correlação positiva com hemorragia pulmonar induzida por exercício, sendo que apenas para a segunda foi estatisticamente significativa. / Exercise-induced pulmonary hemorrhage (EIPH) is characterize by blood found in upper and lower respiratory tract. It is considered by many authors to have a negative effect on the athletic performance of racing horses, causing significantive economic losses. Some authors suggest that obstructive and inflammatory process breaks out HPIE, but this question hasn´t been settled so far. The aim of this study is to identify the relations between exercise-induced pulmonary hemorrhage and alterations of upper airways and trachea on Thoroughbreds racehorses that raced at the tracks of the São Paulo Jockey Club from March, 1999 to September, 2005. The endoscopic examination was made 30 minutes after the race by a single examiner, and 4036 results have been analyzed. Among these horses, 2229 took previous furosemide medication and 1737 didn´t. The results regarding the presence of EIPH were 52.40% for the first group and 60% for the second, with no significant difference related to age and sex. However, the prevalence of grade 4 EIPH among females was two times bigger than among males. No positive relation between EIPH and alterations of upper airways and trachea was observed, although in dorsal displacement of the soft palate that was statistically significantive or with recurrent laryngeal neuropathy left although no statistically significative. The horses that presented disease of upper airways didn´t any relation with EIPH. Among alterations of upper airways analyzed, the recurrent laryngeal neuropathy left and dorsal displacement of the soft palate showed positive relation with EIPH, and only the second one was statistically significative.

The humerus of a racing horse Thoroughbred is highly susceptible to stress fractures at a characteristic location as a result of cyclic loading. The propensity of a Thoroughbred to exhibit humeral fracture has made equines useful models in the epidemiology of stress fractures. In this study, a racing Thoroughbred humerus was simulated during training using a 3D finite element model in conjunction with a bone remodeling algorithm. Nine muscle forces and two contact forces were applied to the 3-dimensional finite element model, which contains four separate load cases representing fore-stance, mid-stance, aft-stance, and standing. Four different training programs were incorporated into the model, which represent Baseline Layup and Long Layup training programs along with two newly implemented programs for racing, which have an absence of a layup period, last a period of 24 weeks, and a race once every four weeks. Muscle and contact forces were rescaled for all load cases to simulate dirt, turf, and synthetic track surfaces. Bone porosity, damage, and BMU activation frequency were examined at the stress fracture site and compared with a control location called the caudal diaphysis. It was found that race programs exhibited similar remodeling patterns between each other. Damage at the stress fracture site and caudal diaphysis was reduced during all training programs for the turf and synthetic track surfaces with respect to the dirt track surface. Key findings also included changes in bone remodeling at the stress fracture site and caudal diaphysis as a result of turf and synthetic track surfaces. This model can serve as a framework for further studies in human or equine athletes who are susceptible to stress fractures.