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Bystrom, A.; Roepstorff, L.; Johnston, C. |
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Title |
Effects of draw reins on limb kinematics |
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Journal Article |
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Year |
2006 |
Publication |
Equine Veterinary Journal. Supplement |
Abbreviated Journal |
Equine Vet J Suppl |
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Volume |
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Issue |
36 |
Pages |
452-456 |
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Animals; Biomechanics; Exercise Test; Forelimb/physiology; Head/physiology; Hindlimb/physiology; Horses/*physiology; Humans; Movement/physiology; Neck/physiology; Physical Conditioning, Animal/*methods/*physiology; Weight-Bearing/physiology |
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REASONS FOR PERFORMING STUDY: No data exist on the GRF-kinematics relation due to changes caused by equestrian interventions. HYPOTHESIS: Through the judicious use of draw reins the rider can influence the kinematics of the horse to meet stated goals of dressage training. Relating the results to previously published kinetic data of the same experiment implies a possible relationship between kinetics and kinematics. METHODS: The kinematics of 8 sound Swedish Warmblood horses were measured whilst the horses were being ridden with and without draw reins. Three conditions were evaluated: 1) draw reins only (DR), 2) combination of draw reins and normal reins (NR+DR) and 3) normal reins only (NR). RESULTS: Head and neck angles were significantly decreased by the draw rein but 4-5 times more so for DR when with NR+DR. The forelimb position at hoof lift-off was significantly more caudal with DR. In the hind limb the hip joint extended more quickly and the hock joint flexed more with NR+DR than with NR. Compared to DR the hip joint angular pattern was not significantly different, but the pelvis was more horizontal. CONCLUSION: Riding with a draw rein can have significant influence on the kinematics of the horse. Some of the observed changes can be coupled to changes in kinetics. The hock joint angle seems to be a fairly reliable indicator of load on the hind limb and the angle of femur appears important for hind limb propulsion, when considered in conjunction with the orientation of the pelvis. POTENTIAL RELEVANCE: These findings are important for riders and trainers, as kinematic changes are what trainers observe. It is thereby important to ascertain which kinematic changes are consistently coupled to changes in kinetics in order for trainers to be able to judge correctly the success of intended goals. Further studies are warranted to validate and confirm suggested relationships between kinetics and kinematics. |
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Department of Equine Studies, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden |
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PMID:17402465 |
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Equine Behaviour @ team @ |
Serial |
3701 |
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Author |
Clayton, H.M.; Lanovaz, J.L.; Schamhardt, H.C.; van Wessum, R. |
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Title |
The effects of a rider's mass on ground reaction forces and fetlock kinematics at the trot |
Type |
Journal Article |
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Year |
1999 |
Publication |
Equine Veterinary Journal. Supplement |
Abbreviated Journal |
Equine Vet J Suppl |
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Volume |
30 |
Issue |
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Pages |
218-221 |
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Keywords |
Animals; Body Weight; Computer Simulation; Gait/*physiology; Horses/*physiology; Physical Conditioning, Animal/*physiology; Stress, Mechanical; Weight-Bearing/*physiology |
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Ground reaction force (GRF) measurements are often normalised to body mass to facilitate inter-individual comparisons. The objective of this study was to explore the effect of a rider on the GRFs and fetlock joint kinematics of trotting horses. The subjects were 5 dressage-trained horses and 3 experienced dressage riders. Ground reaction force measurements and sagittal view videotapes were recorded as the horses trotted at the same velocity in hand (3.49 +/- 0.52 m/s) and with a rider (3.49 +/- 0.46 m/s). Data were time-normalised to stance duration. Ground reaction force measurements were expressed in absolute terms and normalised to the system mass (horse or horse plus rider). All the horses showed changes in the same direction when comparing the ridden condition with the in-hand condition. There was an increase in the absolute peak vertical GRFs of the fore- and hindlimbs with a rider. However, the mass-normalised peak vertical GRFs were lower for the ridden condition, with the peak occurring later in the forelimbs and earlier in the hindlimbs compared with the inhand condition. Maximal fetlock angle and its time of occurrence were similar for the 2 conditions, but the fore fetlock joint was more extended during the later part of the stance phase in ridden horses. The presence of a rider appeared to affect the GRFs and fetlock joint kinematics differently in the fore- and hindlimbs, and the ridden horse did not seem to be equivalent to a proportionately larger horse. This should be considered when normalising for body mass in studies comparing horses in hand and ridden horses. |
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Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824-1314, USA |
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PMID:10659255 |
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Equine Behaviour @ team @ |
Serial |
3733 |
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Doherty, T.J.; Frazier, D.L. |
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Title |
Effect of intravenous lidocaine on halothane minimum alveolar concentration in ponies |
Type |
Journal Article |
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Year |
1998 |
Publication |
Equine veterinary journal |
Abbreviated Journal |
Equine Vet J |
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Volume |
30 |
Issue |
4 |
Pages |
300-303 |
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Keywords |
Anesthetics/administration & dosage/blood/*pharmacology; Anesthetics, Inhalation/administration & dosage/*analysis; Animals; Consciousness/drug effects; Dose-Response Relationship, Drug; Halothane/administration & dosage/*analysis; Horses/*physiology; Infusions, Intravenous/veterinary; Lidocaine/administration & dosage/blood/*pharmacology; Male |
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Abstract |
This study investigated the effect of lidocaine i.v. on halothane minimum alveolar concentration (MAC) in ponies. Six ponies were anaesthetised with thiopentone and succinylcholine, intubated and anaesthesia maintained with halothane. Ventilation was controlled and blood pressure maintained within clinically acceptable limits. Following a 2 h equilibration period, baseline halothane MAC was determined. The ponies were then given a loading dose of lidocaine (2.5 or 5 mg/kg bwt) or saline over 5 min, followed by a constant infusion of lidocaine (50 or 100 microg/kg/min, or saline, respectively). The halothane MAC was redetermined after a 60 min infusion of lidocaine or saline. The baseline halothane MAC for the control group was mean +/- s.d. 0.94 +/- 0.03%, and no significant decrease occurred following saline infusion. Lidocaine decreased halothane MAC in a dose-dependent fashion (r = 0.86; P < 0.0003). The results indicate that i.v. lidocaine may have a role in equine anaesthesia. |
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Department of Large Animal Clinical Sciences, University of Tennessee, College of Veterinary Medicine, Knoxville 37901-1071, USA |
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0425-1644 |
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PMID:9705112 |
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refbase @ user @ |
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95 |
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van der Kolk, J.H.; Nachreiner, R.F.; Schott, H.C.; Refsal, K.R.; Zanella, A.J. |
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Title |
Salivary and plasma concentration of cortisol in normal horses and horses with Cushing's disease |
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Journal Article |
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Year |
2001 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
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Volume |
33 |
Issue |
2 |
Pages |
211-213 |
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Adrenal Cortex Function Tests/standards/veterinary; Animals; Cushing Syndrome/diagnosis/metabolism/*veterinary; Female; Horse Diseases/blood/*diagnosis/metabolism; Horses/blood/*metabolism; Hydrocortisone/blood/*metabolism; Male; Predictive Value of Tests; Reference Values; Saliva/*metabolism |
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Department of Large Animal Medicine and Nutrition, Veterinary Faculty, Utrecht University, The Netherlands |
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0425-1644 |
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PMID:11266074 |
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Equine Behaviour @ team @ |
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4281 |
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Trim, C.M.; Moore, J.N.; Clark, E.S. |
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Title |
Renal effects of dopamine infusion in conscious horses |
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Journal Article |
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Year |
1989 |
Publication |
Equine veterinary journal. Supplement |
Abbreviated Journal |
Equine Vet J Suppl |
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Issue |
7 |
Pages |
124-128 |
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Animals; Blood Pressure/drug effects/physiology; Consciousness/*physiology; Creatinine/blood; Dopamine/administration & dosage/*pharmacology; Dose-Response Relationship, Drug; Female; Heart Rate/drug effects/physiology; Horses/*physiology; Infusions, Intravenous/veterinary; Kidney/blood supply/*drug effects/physiology; Osmolar Concentration; Potassium/blood; Random Allocation; Regional Blood Flow/drug effects/physiology; Renal Artery/drug effects/physiology/ultrasonography; Sodium/blood; Time Factors; Ultrasonography/methods/veterinary; Urination/physiology |
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An ultrasonic flow probe was implanted around a branch of the left renal artery in five horses. The effects of dopamine were studied in the unsedated horses 10 days after surgery. Three experiments, separated by at least two days, were performed in random order on each horse. In two experiments, dopamine was infused intravenously for 60 mins at either 2.5 and 5.0 micrograms/kg bodyweight (bwt)/min. Saline was infused for 60 mins before and after each infusion, and for 180 mins in the third experiment as a control. Renal blood flow increased during administration of dopamine at both dose rates (P = 0.0001). Urine volume increased (P = 0.055), and osmolality decreased (P < 0.05), with infusion of dopamine at 5.0 micrograms/kg bwt/min. Arterial blood pressure and heart rate were not significantly affected. Fractional excretions of sodium and potassium were not significantly changed with dopamine infusion. The higher dopamine dose rate was accompanied by dysrhythmias in some horses. |
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Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602, USA |
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PMID:9118094 |
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no |
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refbase @ user @ |
Serial |
99 |
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Author |
Husted, L.; Andersen, M.S.; Borggaard, O.K.; Houe, H.; Olsen, S.N. |
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Title |
Risk factors for faecal sand excretion in Icelandic horses |
Type |
Journal Article |
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Year |
2005 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
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Volume |
37 |
Issue |
4 |
Pages |
351-355 |
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Animal Feed; Animal Husbandry/methods; Animals; Denmark; Feces/*chemistry; Female; Gastrointestinal Diseases/epidemiology/etiology/prevention & control/veterinary; Horse Diseases/epidemiology/etiology/prevention & control; Horses/*metabolism; Logistic Models; Male; Pilot Projects; *Poaceae/growth & development; Risk Factors; Silicon Dioxide/administration & dosage/adverse effects/*analysis; Soil/*analysis |
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REASONS FOR PERFORMING STUDY: Sandy soil is often mentioned as a risk factor in the development of sand-related gastrointestinal disease (SGID) in the horse. There are other variables, but few studies confirm any of these. OBJECTIVE: To investigate soil type, pasture quality, feeding practice in the paddock, age, sex and body condition score as risk factors for sand intake in the horse. METHODS: Faeces were collected from 211 Icelandic horses on 19 different studs in Denmark together with soil samples and other potential risk factors. Sand content in faeces determined by a sand sedimentation test was interpreted as evidence of sand intake. Soil types were identified by soil analysis and significance of the data was tested using logistic analysis. RESULTS: Of horses included in the study, 56.4% showed sand in the faeces and 5.7% had more than 5 mm sand as quantified by the rectal sleeve sedimentation test. Soil type had no significant effect when tested as main effect, but there was interaction between soil type and pasture quality. Significant interactions were also found between paddock feeding practice and pasture quality. CONCLUSION: To evaluate the risk of sand intake it is important to consider 3 variables: soil type, pasture quality and feeding practice. Pasture quality was identified as a risk factor of both short and long grass in combination with sandy soil, while clay soil had the lowest risk in these combinations. Feeding practice in the paddock revealed feeding directly on the ground to be a risk factor when there was short (1-5 cm) or no grass. Also, no feeding outdoors increased the risk on pastures with short grass, while this had no effect in paddocks with no grass. More than 50% of all horses investigated in this study had sand in the faeces. POTENTIAL RELEVANCE: The identification of risk factors is an important step towards prevention of SGID. Further research is necessary to determine why some horses exhibit more than 5 mm sand in the sedimentation test and whether this is correlated with geophagic behaviour. |
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Department of Large Animal Sciences, The Royal Veterinary and Agricultural University, Dyrlaegevej 88, DK-1870 Frederiksberg, Denmark |
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0425-1644 |
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PMID:16028626 |
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Serial |
1888 |
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Madigan, J.E.; Kortz, G.; Murphy, C.; Rodger, L. |
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Title |
Photic headshaking in the horse: 7 cases |
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Journal Article |
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Year |
1995 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
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27 |
Issue |
4 |
Pages |
306-311 |
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Animals; Anti-Allergic Agents/therapeutic use; *Behavior, Animal; Cyproheptadine/therapeutic use; Female; *Head; Horse Diseases/drug therapy/*etiology; Horses; Light/*adverse effects; Male; Movement Disorders/drug therapy/etiology/*veterinary |
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Seven horses with headshaking are described. No physical abnormalities were detected in any of the cases. Six of these horses had onset of clinical signs in the spring. The role of light was assessed by application of a blindfold or dark grey lens to the eyes, covering the eyes with a face mask and observing the horse in total darkness outdoors. Cessation of headshaking was observed with blindfolding (5/5 horses), night darkness outdoors (4/4 horses) and use of grey lenses (2/3 horses). Outdoor behaviour suggested efforts to avoid light in 4/4 cases. The photic sneeze in man is suggested as a putative mechanism for equine headshaking. Five of 7 horses had improvement with cyproheptadine treatment (0.3 mg/kg bwt b.i.d.). Headshaking developed within 2 calendar weeks of the same date for 3 consecutive years in one horse. Neuropharmacological alterations associated with photoperiod mechanisms leading to optic trigeminal summation are suggested as possible reasons for spring onset of headshaking. |
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Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis 95616-8737, USA |
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0425-1644 |
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PMID:8536668 |
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refbase @ user @ |
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1940 |
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Houpt, K.A.; Eggleston, A.; Kunkle, K.; Houpt, T.R. |
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Title |
Effect of water restriction on equine behaviour and physiology |
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Journal Article |
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Year |
2000 |
Publication |
Equine veterinary journal |
Abbreviated Journal |
Equine Vet J |
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Volume |
32 |
Issue |
4 |
Pages |
341-344 |
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Animals; *Behavior, Animal; Blood Proteins/analysis; Energy Intake; Female; Horse Diseases/physiopathology; Horses/*physiology; Osmolar Concentration; Pregnancy; Stress/veterinary; Video Recording; Water Deprivation/*physiology |
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Six pregnant mares were used to determine what level of water restriction causes physiological and/or behavioural changes indicative of stress. Nonlegume hay was fed ad libitum. During the first week of restriction, 5 l water/100 kg bwt was available, during the second week 4 l/100 kg bwt and, during the third week, 3 l/100 kg bwt. Ad libitum water intake was 6.9 l/100 kg bwt; at 3 l/100 kg bwt water intake was 42% of this. Daily hay intake fell significantly with increasing water restriction from 12.9 +/- 0.75 kg to 8.3 +/- 0.54 kg; bodyweight fell significantly for a total loss of 48.5 +/- 8.3 kg in 3 weeks. Daily blood samples were analysed; osmolality rose significantly with increasing water restriction from 282 +/- 0.7 mosmols/kg to 293.3 +/- 0.8 mosmols/kg bwt, but plasma protein and PCV did not change significantly. Cortisol concentrations fell from 8.1 ng/ml to 6.4 ng/ml over the 3 week period. Aldosterone fell from 211.3 +/- 74.2 pg/ml to 92.5 +/- 27.5 pg/ml at the end of the first week. The behaviour of 4 of the 6 mares was recorded 24 h/day for the duration of the study. The only significant difference was in time spent eating, which decreased with increasing water restriction from 46 +/- 3% to 30 +/- 3%. It is concluded that water restriction to 4 l/100 kg bwt dehydrates pregnant mares and may diminish their welfare, but is not life- or pregnancy-threatening. |
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Department of Physiology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853-6401, USA |
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PMID:10952384 |
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refbase @ user @ |
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32 |
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Shaw, E.B.; Houpt, K.A.; Holmes, D.F. |
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Title |
Body temperature and behaviour of mares during the last two weeks of pregnancy |
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Journal Article |
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Year |
1988 |
Publication |
Equine veterinary journal |
Abbreviated Journal |
Equine Vet J |
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Volume |
20 |
Issue |
3 |
Pages |
199-202 |
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Animals; *Behavior, Animal; *Body Temperature; Circadian Rhythm; Eating; Female; Horses/*physiology; Labor, Obstetric/*physiology; Motor Activity; Pregnancy; Pregnancy, Animal/*physiology |
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Abstract |
Average daily core body temperature and behavioural patterns of pregnant mares were studied, in search of definitive signs of parturition within 24 h of the event. Nineteen pony mares were sampled twice daily for core body temperature. A significant temperature drop, averaging 0.1 degrees C (0.2 degrees F) was observed during the day prior to parturition. Between 18.00 h and 06.00 h, during the two weeks before parturition, Thoroughbred and Standardbred mares (n = 52) spent an average 66.8 per cent of their time standing, 27.0 per cent eating, 4.9 per cent lying in sternal recumbency, 1.0 per cent lying in lateral recumbency, and 0.3 per cent walking. On the night before parturition, mares spent significantly less time lying in sternal recumbency than on previous nights and on the night of parturition all behaviour patterns except eating were significantly different from the nights of the two weeks before parturition. There was an increase in walking (5.3 per cent), lying in sternal recumbency (8 per cent) and lying in lateral recumbency (5.3 per cent) whereas standing (53.3 per cent) was decreased. In 58 observed pregnancies, 54 mares (97 per cent) foaled in a recumbent position and 50 mares (86 per cent) foaled between 18.00 h and 06.00 h. |
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Department of Physiology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853 |
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0425-1644 |
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PMID:3402416 |
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refbase @ user @ |
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46 |
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Harman, A.M.; Moore, S.; Hoskins, R.; Keller, P. |
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Title |
Horse vision and an explanation for the visual behaviour originally explained by the 'ramp retina' |
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Journal Article |
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Year |
1999 |
Publication |
Equine veterinary journal |
Abbreviated Journal |
Equine Vet J |
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Volume |
31 |
Issue |
5 |
Pages |
384-390 |
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Animals; Behavior, Animal; Cell Count; Eye/*anatomy & histology; Ganglia, Sensory/cytology; Horses/*physiology; Refractive Errors/veterinary; Retina/cytology/*physiology; Vision/*physiology; Visual Acuity; Visual Fields |
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Here we provide confirmation that the 'ramp retina' of the horse, once thought to result in head rotating visual behaviour, does not exist. We found a 9% variation in axial length of the eye between the streak region and the dorsal periphery. However, the difference was in the opposite direction to that proposed for the 'ramp retina'. Furthermore, acuity in the narrow, intense visual streak in the inferior retina is 16.5 cycles per degree compared with 2.7 cycles per degree in the periphery. Therefore, it is improbable that the horse rotates its head to focus onto the peripheral retina. Rather, the horse rotates the nose up high to observe distant objects because binocular overlap is oriented down the nose, with a blind area directly in front of the forehead. |
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Address |
Department of Psychology, University of Western Australia, Nedlands, Australia |
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Publisher |
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Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0425-1644 |
ISBN |
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Expedition |
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Conference |
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Notes |
PMID:10505953 |
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no |
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Call Number |
refbase @ user @ |
Serial |
836 |
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