Continuous Urethral Spasm Responsive to Acepromazine in a Mare

A Standardbred mare presented with a 3-year history of stranguria and pollakiuria. Urethral spasm was detected by transrectal and digital examination. Ancillary diagnostic tests revealed no abnormal findings. The mare recovered after a 1-month treatment with acepromazine. Similar cases and responses to treatment have not been reported before in horses.     

Stress Response of Three-year-old Horse Mares to Changes in Husbandry System During Initial Equestrian Training

For initial training, horses are often transferred from group housing to individual boxes, which is a potential stressor. In this study, salivary cortisol concentrations, locomotion activity, and heart rate (HR) were analyzed and the HR variability (HRV) variables standard deviation of beat-to-beat interval (SDRR) and root mean square of successive RR differences (RMSSD) were calculated in 3-year-old mares (n = 8). Mares were transferred abruptly from a group stable with access to a paddock to individual boxes without a paddock and were studied from 4 days before to 5 days after changing the stable. Mares underwent routine equestrian training for young horses. On the days before mares were moved to individual boxes, cortisol concentrations showed a diurnal rhythm with values approximately 0.6 ng/ml in the morning and a decrease throughout the day. When horses were moved to individual boxes, cortisol concentrations increased to 1.8 ± 0.2 ng/ml within 30 minutes and did not return to baseline values within 6 hours (0.7 ± 0.1 ng/ml, P < .05 over time). On the following days, a diurnal rhythm was re-established but at a higher level than before the change of stable. Locomotion activity was higher when mares had access to a paddock than when kept in individual boxes. Heart rate increased for approximately 60 minutes when mares were separated from their group. In conclusion, separating young horses from their group and individual stabling are perceived as stressful.     

Effect of Experience on Adrenocortical and Thyroid Responses of Arabian Horses to Gymkhana Games

Gymkhana is an equestrian event consisting of speed pattern racing and timed games for riders on horses. The aim of the study was to evaluate the effects of gymkhana competition on total cortisol and total and free iodothyronine changes in 23 Arabian purebred horses, by taking into account the effects of previous sport experience on gymkhana riding events. Compared with pre-competition values, an increase of total cortisol concentration has been observed in experienced horses at 30 minutes (P < .001) after exercise and in inexperienced horses both at 5 minutes (P < .05) and at 30 minutes (P < .01) after exercise. Compared with pre-competition values, an increase of total triiodothyronine (T₃) concentration has been observed in experienced horses at 5 minutes (P < .05) after exercise. Data obtained showed that gymkhana riding events induced differential adrenocortical and thyroid responsiveness according to previous experience of sport horses. Hence, cortisol and iodothyronine patterns may provide additional information for the monitoring of gymkhana riding performance.     

Cardiac Power Output during Dobutamine Stress Test in Horses

Although echocardiography has greatly improved the diagnostic possibilities in equine medicine, determining the prognosis remains a difficult task. In humans, maximal cardiac power output (CPO) has been described as a powerful indicator of exercise capability and outcome in heart disease. The aim of the study is to describe the measurement of CPO by echocardiography and by thermodilution in healthy horses. Six healthy horses were studied. Cardiac output (CO) was measured by thermodilution and Doppler echocardiography at rest and during a pharmacologic stress test consisting of 35 μg/kg atropine followed by incremental steps 2, 4, 6, and 8 μg/kg/min of dobutamine infusion. Mean arterial pressure (MAP) was measured invasively by a catheter introduced into the transverse facial artery. CPO was calculated as the product of CO and MAP. Baseline CPO measured by thermodilution and by Doppler echocardiography was 10.7 ± 3.3 and 13.7 ± 4.5 watts, respectively. CPO increased significantly with pharmacologic stimulation and reached maximal CPO of 66.4 ± 3.6 and 60.4 ± 5.1 watts when measured by thermodilution and Doppler echocardiography, respectively. This study describes an estimation of CPO in horses. Further studies should demonstrate the usefulness of CPO as a predictive indicator in horses suffering from cardiac disease.     

Rider and Horse Salivary Cortisol Levels During Competition and Impact on Performance

During competition, stress may affect riders and horses. This stress can affect health, welfare, and/or performance. Our aim was to quantify stress levels during competition in horses and riders. We also searched relationships between these stress levels and performance. Twenty riders and 23 horses were followed up during a show-jumping event (26 courses) held at a riding school. Regular saliva samples taken from horses and riders were assayed to evaluate cortisol levels. We studied salivary cortisol evolution during the days of competition. There was no correlation between instantaneous sampling on horses and their riders. However, we did find a parallel between horse and rider salivary cortisol evolution curves, with a similar peak, reached 20 minutes after the course. The increase was stronger in riders than in horses. Correlations appeared between salivary cortisol concentration and performance, but stress in both partners seems to have an opposite influence on performance. Riders who showed a higher salivary cortisol increase were awarded more penalties, whereas horses that showed a higher increase in salivary cortisol performed better. Stress level measurement in rider–horse pairs would thus lead to improvement in competition conditions and performance, for horses as well as for riders.     

Prognostic Significance of Oxidative Stress Markers in Colitis Associated with Phenylbutazone Administration in Draft Horses

The present study was carried out to assess the prognostic significance of oxidative stress markers in draft horses with colitis associated with phenylbutazone administration under field condition. For this purpose, a total of 40 native breed draft horses were studied. Based on case history, physical examination, and postmortem findings, diagnosis was made. According to the clinical outcome, horses were categorized into survivors and nonsurvivors. Clinically, there was significant association between nonsurvivors and anorexia (P < .01), stasis of intestinal motility (P < .01), melena (P < .01), and diarrhea (P < .001). Biochemically, malondialdehyde and nitric oxide showed a significant increase (P < .05) in nonsurvivors compared with survivors, whereas activities of superoxide dismutase showed a significant decrease (P < .05). Analysis of receiver operating characteristic curve indicated a high sensitivity and specificity of malondialdehyde, nitric oxide, and superoxide dismutase levels (P < .001) to predict the clinical outcome of colitis. Additionally, total protein and albumin showed a significant decrease in nonsurvivors compared with survivors; however, aspartate aminotransferase, sorbitol dehydrogenase, urea, and creatinine showed an increase (P < .05). The present results suggest that estimation of oxidative stress markers and antioxidant parameters may be useful predictors of the clinical outcomes of colitis associated with phenylbutazone administration in draft horses.     

Gender Differences of Oxidative Stress Biomarkers and Erythrocyte Damage in Well-Trained Horses During Exercise

The aim of this study was to determine the effects of gender differences on the blood oxidative stress biomarkers, antioxidant defenses, and resistance of erythrocytes to hemolytic agents of trained horses before and after exercise. The study was carried out on nine mares and 14 stallions of Ukrainian Warmblood well-trained horses, involved in jumping, eventing, and dressage. Oxidative stress biomarkers, antioxidant defenses, and osmotic resistance of erythrocytes were assessed. Trained stallions showed a decrease in lipid peroxidation and higher glutathione reductase activity, whereas mares presented a higher superoxide dismutase activity after exercise. The resistance of erythrocytes was similar in female and male. No statistically significant differences were observed in the percentage of hemolyzed erythrocytes between after and before exercise. A correlation between the oxidative stress biomarkers and antioxidant defenses in the stallions after exercises were observed, which may indicate a protective response of superoxide dismutase and catalase against exercise-induced oxidative stress.     

Efficacy of Hyperimmunized Plasma in the Treatment of Horses with Acute Colitis

Colitis in the adult horse is a life-threatening clinical condition that can be caused by any of several enteric pathogens. This study was conducted to determine whether treating horses with plasma obtained from donors that were hyperimmunized against the common equine diarrheal pathogens Clostridium difficile, Clostridium perfringens, and Salmonella sp shortens the duration of diarrhea in acute colitis. To evaluate the efficacy of plasma treatment, 42 horses with acute onset of diarrhea were studied. Horses were enrolled if they were of age >1 year, duration of diarrhea at presentation was <72 hours, and they had not received equine plasma within the last 3 months. In addition, the serum cortisol concentrations of horses with acute diarrhea were studied.Horses were randomized to receive hyperimmunized plasma, control plasma (collected from nonimmunized horses), or no plasma therapy. Clinical parameters and fecal consistency were observed until resolution, discharge, or death, and complete blood counts (CBCs) and biochemical profiles were collected throughout the study. A total of 38 horses completed the study. The mean duration of diarrhea was 40.7 ± 9.8 (mean ± SEM) hours, 119.2 ± 56.1 hours, and 72.0 ± 24.5 hours for the hyperimmunized plasma, normal plasma (NP), and control groups, respectively. Using survival analysis techniques, this difference did not achieve statistical significance (P = .374). Serum cortisol was found to be increased in all horses at presentation and to decrease with time in all treatment groups. There was no difference in cortisol concentrations between the three treatment groups studied (P = .237).     

Effects of Density and Water Availability on the Behavior, Physiology, and Weight Loss of Slaughter Horses during Transport

The aim of this study was to determine the effects of density and provision of water on aggressive behavior, stress, and weight loss in slaughter horses during transport. A 16.2-m, single deck semi-trailer was divided into three compartments to create high, medium, and low density (397 ± 6.5 kg/m², 348 ± 5.2 kg/m², and 221 ± 7.6 kg/m² per compartment) groups of unrestrained horses. Six shipments containing 23 to 30 horses per shipment were transported in June and July of 2004 for 18 to 20 hours. While the truck was stopped for 1 hour after 8 hours of transport and then again just before unloading, horses in each of two compartments received water for 1 hour from six water bowls (three bowls mounted on each side of a compartment). The third, non-watered compartment served as a control. Aggressive behavior of the horses was recorded using 12 video cameras installed in the trailer. All occurrences of aggressive behavior were counted from 15-minute segments of video during 2-hour intervals for each horse that was visible in each density group. Neither density nor water significantly affected (P > 0.21) aggressive behavior, cortisol, plasma chemistry profile, dehydration, or weight loss. Aggression did not differ (P = 0.49) between the first and second halves of the shipments, indicating that fatigue had not advanced to the stage where aggression was suppressed. Individual horses, rather than density were the major cause of aggressive behavior. However, two horses went down in the high density treatment, indicating that factors in high density could lead to increased morbidity or death.     

Aquapuncture Improves Metabolic Capacity in Thoroughbred Horses

The aim of this study was to evaluate the effect of aquapuncture on muscle enzymes release and cardiovascular and metabolic variables of Thoroughbred horses during and after exercise. Eighteen healthy Thoroughbred horses, submitted to training for competition, were used. The animals were randomly allotted into three groups: ConG (negative control group), ShG (sham aquapuncture or positive control group), and AcuG (treatment aquapuncture group). The treatments were done twice per week, during a 3-week interval. Physical performance was evaluated under field conditions, with two submaximal incremental velocity tests, separated by a 3-week period. The tests included evaluation of cardiovascular (V₂₀₀) and metabolic (V_La4) capacities and measurement of creatine kinase (CK) and aspartate aminotransferase (AST) before and after exercise. V₂₀₀ values were not different between times or groups. V_La4 values were statistically greater after treatment for the AcuG group compared with pretreatment. CK concentrations were statistically greater after exercise for all groups, and AST concentrations were not different between times or groups. Aquapuncture influenced neither cardiovascular capacity nor the release of muscle enzymes; however, it did improve metabolic capacity of Thoroughbred horses.     

Acupuncture Needle Stimulation on Some Physiological Parameters After Road Transport and Physical Exercise in Horse

The aim of this study was to evaluate the effect of acupuncture (AG) treatment on some hematochemical parameters in five Thoroughbred horses after road transport and exercise. Horses competed in two official races. For each race, animals were transported from their stables to the racetrack. Horses transported and competed in the first race represent the control group. Two weeks later, the same horses competed in the second race. Before road transport, they were treated with AG. From animals, blood samples were collected at rest (T_PRE), after unloaded (T_POST), 30 minutes after unloaded (T_POST30), at rest in the transit stall (R_PRE), at the end of the race (R_POST), and 30 minutes after the race (R_POST30). The effect of transport, exercise, and AG was evaluated on blood lactate, glucose, red blood cell, hemoglobin, hematocrit, mean corpuscular volume, and erythrocyte osmotic fragility (EOF) values. A significant effect of transport (P < .05) and exercise (P < .01) was found on all studied parameters in both groups. A significant effect of AG on lactate, glucose, and EOF values was found in transported (P < .001) and exercised horses (P < .05). The results found in this study showed that transport and exercise are potential stressors for the athlete horse that may affect its welfare and physical performance. The data suggest that AG stimulation promoted the increase of blood glucose values and the reduction of lactate and EOF levels suggesting its role in the improvement of the physiological adaptation to stressful stimuli and of physical performance of Thoroughbred horses.     

断奶仔猪应激期肠道健康及营养调控的研究进展

仔猪断奶后需经历环境变化、饲粮转变以及自身肠道结构与功能改变,易发生断奶应激,直接影响养猪生产的效率.因此,研究缓解断奶仔猪应激的调控措施对养猪生产具有重要意义.本文分别从肠道健康和营养调控两方面出发,对近年来关于仔猪断奶应激的调控措施进行综述,以期为进一步研究仔猪断奶应激和健康养殖提供理论依据和调控思路.     

Effect of Lavender Aromatherapy on Acute-Stressed Horses

Methods to reduce the effects of acute stress could benefit the equine industry; therefore, the objective of this experiment was to determine whether aromatherapy would hasten the recovery time in acute-stressed horses. A total of seven horses were used in this experiment, using a crossover design where each horse received each treatment 7 days apart. The heart rates (HRs) and respiratory rates (RRs) were recorded for each horse at rest in stalls; then an air horn was blown twice for 15 seconds. The horses were allowed 60 seconds to calm, and then the stressed HRs and RRs were recorded. Control-treated horses were then exposed to humidified air, whereas aromatherapy-treated horses were exposed to humidified air with a 20% mixture of 100% pure lavender essential oil for 15 minutes. Following the 15-minute control or aromatherapy treatment, the recovery HRs and RRs were recorded (15 minutes). There were no statistical differences (P > .05) between the control and aromatherapy treatment for resting HR 33.7 ± 3.6 versus 34.0 ± 3.1 beats per minute (bpm), or change to increased HR in response to the air horn. However, the change in HR, after treatment, was significantly greater (P < .02) after aromatherapy (−9.25 ± 3.4 bpm) compared with the control treatment (0.29 ± 1.5 bpm). The RR did not differ (P > .05) between the control or aromatherapy treatment groups for the resting RR or change in RR. These results demonstrate that lavender aromatherapy can significantly decrease HR after an acute stress response and signal a shift from the sympathetic nervous control from the parasympathetic system.     

24-Hour Endocrine Profiles of Quarter Horses under Resting Conditions

The aim of this research was to evaluate the changes in β-endorphin, cortisol, total and free iodothyronines, and estradiol-17β levels of 10 unfit Quarter horses undergoing training under resting conditions during a 24-hour period. All animals that were sedentary since 3 months were divided into two groups comprising five animals each: group I, pre-trained for western riding (age: 8.8 ± 6.7 years; two stallions, one gelding, and two mares) and group II, not pre-trained for western riding (age: 9.4 ± 6.8 years; one stallion, three geldings, and one mare). Blood samples were collected from horses under resting conditions every 4 hours, from 5.30 am to 5.30 am of the next day. A two-way analysis of variance with repeated measures showed that the interaction between pre-training status and sampling time was not significant for hormone changes, but tended to be significant for fT₃ changes (P < .06). The effects of pre-training status were considered significant for fT₃ (P < .02). Time had significant effects on β-endorphin (P < .01), cortisol (P < .02), fT₃ (P < .0001), and estradiol-17β (P < .0001) changes. Therefore, it seems to be extremely useful to take into account hormone circadian changes to ensure correct performance assessment and to monitor training in Quarter horses.     

Alterations of Endothelium-Dependent Digital Vascular Responses in Horses Given Low-Dose Endotoxin

Low doses of endotoxin cause vasoconstriction and hypoperfusion of the digit, small intestine, and cecum in horses. To determine the potential cause of these vascular alterations, in vitro vascular responses of palmar digital arteries and veins were determined in 8 horses after intravenous (IV) infusion of 1 L 0.9% NaCl (control) and 0.1 μg/kg Escherichia coli 055:B5 endotoxin in 1 L of 0.9% NaCl (endotoxin-treated). Vessels were surgically removed under general anesthesia, cut into 4-mm vascular rings, suspended in tissue baths, and attached to force displacement transducers for measurement of vascular tension. Cumulative concentration response curves to acetylcholine, bradykinin, nitroprusside, norepinephrine, 5-hydroxytryptamine (serotonin), and endothelin were determined. Maximal relaxation or contraction and the concentrations needed to produce 50% maximal relaxation or contraction were determined. Palmar digital arteries from endotoxin-treated horses relaxed significantly less in response to acetylcholine and bradykinin (endothelium-dependent), but not to nitroprusside (endothelium-independent) when compared with arteries from control horses. Digital arteries from endotoxin-treated horses also contracted significantly more with norepinephrine but less with serotonin. Digital veins responded less than digital arteries. In another study, vascular reactivity experiments documented that acetylcholine and bradykinin were endothelium-dependent vasodilators (endothelium-denuded vessels relaxed less than control vessels) in palmar digital vessels. Additionally, maximal relaxations for both vasodilators were significantly inhibited by N-nitro-L-arginine methyl ester (L-NAME), a nitric oxide antagonist, suggesting that acetylcholine and bradykinin cause relaxation through the nitric oxide pathway. The data from these studies indicate that low dose endotoxin impairs endothelium-dependent relaxation and augments adrenergic contraction of palmar digital arteries in horses.     

动物园动物的应激及其管理

应激是圈养野生动物所不能避免的,对动物的负面影响是多方面的。针对动物园动物应激的特点,对动物园存在的应激进行分析归类,阐述应激的危害和解释实践中的问题,采取有效措施对应激进行监测与管理,减弱应激的负面影响。     

紫花苜蓿幼苗生长及其叶片形态对水分胁迫的响应

试验旨在研究紫花苜蓿(Medicago sativa L.)生物量、水分生理状态以及叶片形态对水分胁迫的响应并确定参试紫花苜蓿品种的御旱能力。通过温室盆栽试验,对3个品种的紫花苜蓿进行了4个梯度的水分胁迫处理,测量了根干重、茎干重、叶干重、叶水势、相对叶片含水量、叶长、叶宽、叶面积以及相关指标的胁迫指数。结果显示:紫花苜蓿根、茎、叶的干重对水分胁迫的响应依品种和胁迫程度的不同而不同;随着水分胁迫程度的增加,根冠比呈增大趋势;叶水势、叶片相对含水量、根系含水量胁迫指数以及叶片含水量胁迫指数均呈下降趋势;叶片变短变窄,叶面积变小,比叶面积胁迫指数呈下降趋势。3个紫花苜蓿品种中‘敖汉’的根冠比最大且比叶面积胁迫指数最小,其御旱能力最强,‘中苜1号’次之,‘三得利’最弱。