Lin, Y. - L., Moolenaar, H., van Weeren, P. R., & van de Lest, C. H. A. (2006). Effect of microcurrent electrical tissue stimulation on equine tenocytes in culture. Am J Vet Res, 67(2), 271–276.
Abstract: OBJECTIVE: To determine effects of microcurrent electrical tissue stimulation (METS) on equine tenocytes cultured from the superficial digital flexor tendon (SDFT). SAMPLE POPULATION: SDFTs were collected from 20 horses at slaughter. PROCEDURE: Tenocytes were isolated following outgrowth from explants and grown in 48-well plates. Four methods of delivering current to the tenocytes with a METS device were tested. Once the optimal method was selected, current consisting of 0 (negative control), 0.05, 0.1, 0.5, 1.0, or 1.5 mA was applied to cells (8 wells/current intensity) once daily for 8 minutes. Cells were treated for 1, 2, or 3 days. Cell proliferation, DNA content, protein content, and apoptosis rate were determined. RESULTS: Application of microcurrent of moderate intensity increased cell proliferation and DNA content, with greater increases with multiple versus single application. Application of microcurrent of moderate intensity once or twice increased protein content, but application 3 times decreased protein content. Application of current a single time did not significantly alter apoptosis rate; however, application twice or 3 times resulted in significant increases in apoptosis rate, and there were significant linear (second order) correlations between current intensity and apoptosis rate when current was applied twice or 3 times. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the present study indicate that microcurrent affects the behavior of equine tenocytes in culture, but that effects may be negative or positive depending on current intensity and number of applications. Therefore, results are far from conclusive with respect to the suitability of using METS to promote tendon healing in horses.
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Murray, R. C., Dyson, S. J., Tranquille, C., & Adams, V. (2006). Association of type of sport and performance level with anatomical site of orthopaedic injury diagnosis. Equine Vet J Suppl, (36), 411–416.
Abstract: REASON FOR PERFORMING STUDY: Although anecdotal reports of increased orthopaedic injury risk in equine sports exist, there is little scientific evidence to support this. OBJECTIVES: To test whether horses undertaking a single competitive sport have increased risk of specific injuries compared to those used for general purpose riding (GP); and whether injury type varies with sport category and performance level. METHODS: Data from 1069 records of horses undergoing orthopaedic evaluation (1998-2003) and meeting inclusion criteria were reviewed. Sport category (GP, showjumping, dressage, eventing, racing), level (nonelite or elite) and diagnosis were recorded. Effects of sport category and level on probability of a specific diagnosis were assessed using chi-squared tests. Logistic regression was used to determine which competitive sports and levels increased risk of injury compared with GP. RESULTS: Overall there was a significant effect of sport category and level on diagnosis (P<0.0001). There was significant difference between anatomical site injured and sport category (P<0.0001); a high risk of forelimb superficial digital flexor tendon injury in elite eventing (P<0.0001) and elite showjumping (P = 0.02); distal deep digital flexor tendon (DDFT) injury in elite showjumping (P = 0.002); and hindlimb suspensory ligament injury in elite (P<0.0001) and nonelite (P = 0.001) dressage. There was a low risk of tarsal injury in elite eventing (P = 0.01) and proximal DDFT injury in dressage (P = 0.01). CONCLUSIONS: Horses competing in different sports are predisposed to specific injuries; particular sports may increase the risk of injury at certain anatomical sites; and the type and site of injury may reflect the type and level of performance. POTENTIAL RELEVANCE: These findings could guide clinicians in the diagnosis of sport related injuries.
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Dougherty, D. M., & Lewis, P. (1993). Generalization of a tactile stimulus in horses. J Exp Anal Behav, 59(3), 521–528.
Abstract: Using horses, we investigated the control of operant behavior by a tactile stimulus (the training stimulus) and the generalization of behavior to six other similar test stimuli. In a stall, the experimenters mounted a response panel in the doorway. Located on this panel were a response lever and a grain dispenser. The experimenters secured a tactile-stimulus belt to the horse's back. The stimulus belt was constructed by mounting seven solenoids along a piece of burlap in a manner that allowed each to provide the delivery of a tactile stimulus, a repetitive light tapping, at different locations (spaced 10.0 cm apart) along the horse's back. Two preliminary steps were necessary before generalization testing: training a measurable response (lip pressing) and training on several reinforcement schedules in the presence of a training stimulus (tapping by one of the solenoids). We then gave each horse two generalization test sessions. Results indicated that the horses' behavior was effectively controlled by the training stimulus. Horses made the greatest number of responses to the training stimulus, and the tendency to respond to the other test stimuli diminished as the stimuli became farther away from the training stimulus. These findings are discussed in the context of behavioral principles and their relevance to the training of horses.
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Lagarde, J., Kelso, J. A. S., Peham, C., & Licka, T. (2005). Coordination dynamics of the horse-rider system. J Mot Behav, 37(6), 418–424.
Abstract: The authors studied the interaction between rider and horse by measuring their ensemble motions in a trot sequence, comparing 1 expert and 1 novice rider. Whereas the novice's movements displayed transient departures from phase synchrony, the expert's motions were continuously phase-matched with those of the horse. The tight ensemble synchrony between the expert and the horse was accompanied by an increase in the temporal regularity of the oscillations of the trunk of the horse. Observed differences between expert and novice riders indicated that phase synchronization is by no means perfect but requires extended practice. Points of contact between horse and rider may haptically convey effective communication between them.
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Macfadden, B. J. (2005). Evolution. Fossil horses--evidence for evolution. Science, 307(5716), 1728–1730.
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Altmann, H. J., & Weik, H. (1971). [Serum fatty acid patterns of phospholipid fractions in horses]. Z Tierphysiol Tierernahr Futtermittelkd, 28(5), 285–288.
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Rubin, L., Oppegard, C., & Hindz, H. F. (1980). The effect of varying the temporal distribution of conditioning trials on equine learning behavior. J. Anim Sci., 50(6), 1184–1187.
Abstract: Two experiments were conducted to study the effect of varying the temporal distrbution of conditioning sessions on equine learning behavior. In the first experiment, 15 ponies were trained to clear a small hurdle in response to a buzzer in order to avoid a mild electric shock. Three treatments were used. One group received 10 learning trials daily, seven times a week; one group was trained in the same fashion two times a week and one group was trained once a week. The animals conditioned only once a week achieved a high level of performance in significantly fewer sessions than the ones conditioned seven times a week, although elapsed time from start of training to completion was two to three times greater for the former group. The twice-a-week group learned at an intermediate rate. In the second experiment, the ponies were rearranged into three new groups. They were taught to move backward a specific distance in response to a visual cue in order to avoid an electric shock. Again, one group was trained seven times a week, one group was trained two times and one group was trained once a week. As in the first experiment, the animals trained once a week achieved the learning criteria in significantly fewer sessions than those trained seven times a week, but, as in trial 1, elapsed time from start to finish was greater for them. The two times-a-week group learned at a rate in-between the rates of the other two groups.
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Alexander, F., & Nicholson, J. D. (1968). The blood and saliva clearances of phenobarbitone and pentobarbitone in the horse. Biochem Pharmacol, 17(2), 203–210.
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Alexander, F. (1955). Factors affecting the blood sugar concentration in horses. Q J Exp Physiol Cogn Med Sci, 40(1), 24–31.
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Alexander, F., & Benzie, D. (1951). A radiological study of the digestive tract of the foal. Q J Exp Physiol Cogn Med Sci, 36(4), 213–217.
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