Jumper Horses Research Articles

Dynamic Correlation between Platelet Aggregation and Inflammatory-like State in Athlete Horses

This study aimed to assess the effect of exercise on serum electrophoretic protein pattern, C-reactive protein (CRP) and platelet aggregation in horses subjected to a jumping exercise. The possible relationship between acute-phase reactions and platelet reactivity in the context of exercise was investigated. Blood samples were collected from 10 jumper horses at rest (TREST), within 5 min from the end of exercise (TPE5), and 30 min (TPE30) and 60 min after exercise (TPE60). The serum values of total proteins; CRP; albumin; α1-, α-2, β1-, β2- and γ-globulins; and the maximum degree of aggregation and the initial velocity of aggregation (slope) were evaluated. According to one-way analysis of variance, CRP and α1-, α-2, β1- and β2-globulins increased after exercise compared with rest condition (p < 0.001), whereas albumin and platelet aggregation showed lower values after exercise than at rest (p < 0.001). CRP and α1-globulin values were negatively correlated with both platelet aggregation indices at TPE5, whereas no significant correlation among these parameters was found at TREST, TPE30 and TPE60. This study provides evidence that an acute-phase response occurred in horses after the jumping exercise and suggests a linkage between the inflammatory status and the platelet responsiveness in horses during exercise.

Peripheral Modulators of the Central Fatigue Development and Their Relationship with Athletic Performance in Jumper Horses.

Simple SummaryPhysical exercise induces various stress responses leading to a disturbance of homeostasis and a number of regulatory systems are called upon to return the body to a new level of equilibrium. The aim of this study was to evaluate the peripheral modulators of serotoninergic function and neurohumoral factors’ changes in athletic horses during an official jumping competition, and to evaluate their relationship with the physical performance of competing horses. The findings obtained in the current survey showed that jumping exercise influenced the levels of tryptophan, leucine, valine, non-esterified fatty acids (NEFAs), dopamine, and prolactin and that these changes are related to the physical performance of competing horses. These findings suggest that the serotoninergic system may be involved in fatigue during jumping exercise.The current study aimed to investigate whether peripheral modulators of serotoninergic function and neurohumoral factors’ changes in athletic horses during an official jumping competition, and to evaluate their relationship with the physical performance of competing horses. From 7 Italian Saddle mares (6–9 years; mean body weight 440 ± 15 kg), performing the same standardized warm-up and jumping course during an official class, heart rate (HR) was monitored throughout the competition. Rectal temperature (RT) measurement, blood lactate and glucose concentration, serum tryptophan, leucine, valine, the tryptophan/branched-chain amino-acids ratio (Try/BCAAs), dopamine, prolactin, and non-esterified fatty acids (NEFAs) were assessed before the exercise event (T0), at the end of the competition stage (5 min ± 10 s following the cessation of the exercise, TPOST5), and 30 min after the end of competition (TPOST30). Highest HR values were recorded during the course and at the outbound (p < 0.0001); blood lactate concentration and RT increased after exercise with respect to the rest condition (p < 0.0001). Lower leucine and valine levels (p < 0.01), and higher tryptophan, Try/BCAAs ratio, and NEFAs values were found at TPOST5 and TPOST30 with respect to T0 (p < 0.0001). A higher prolactin concentration was found at TPOST5 and TPOST30 compared to T0 (p < 0.0001), whereas dopamine showed decreased values after exercise compared to rest (p < 0.0001). Statistically significant correlations among the peripheral indices of serotoninergic function, neurohumoral factors, and athletic performance parameters were found throughout the monitoring period. The findings provide indirect evidence that the serotoninergic system may be involved in fatigue during jumper exercise under a stressful situation, such as competition, in which, in addition to physical effort, athletic horses exhibit more passive behavior.

Effects of horse age and the number of riders on equine competitive performance

This article focuses on interspecies communication between rider and jumper horse (show jumpers), as well as its effect on equine sport performance, on the basis of individual differences of riding style and skill. Its primary goal was to discover the consequences of the possible differences in horse performance due to the number of riders who have changed over the course of the horse performing career. Unfortunately, the data used do not allow to determine whether the change of rider also meant a change in the social environment with all contexts (moving the horse to other stable, among other horses, and the use of other training methods). Nevertheless, the change of rider represents a number of individual deviations in the rider's effect on the horse. Riders communicate in the same language, but each rider has a different “handwriting.”The secondary goal of this study is to identify the age at which a competitive jumping horse reaches its maximum competitive performance. A total of 3,097 horse competitive result histories were used in the study, covering participation in 277,198 jumping competitions.The database was divided into three groups as per the competitive success of horses. The data were collected by the Czech Association of Horse Breeders Warmblood on the basis of all horse starts in horse jumping competitions during the years 1997-2009.Within these groups, horses were compared depending on whether they were ridden by one to two riders, three to four riders, and five or more riders over the course of their careers. The results show that among most horse groups their peak performance, represented by the highest level of competition difficulty, was reached in their tenth year of age. In all groups of horses, divided as per their competitive success rates, the best performance was achieved by those with a maximum of two riders over the course of their career. The results clearly speak in favor of both the social stability of horses and performance success of those horses affected by a less frequent change of the rider. It could be stated in accordance with achieved sports results that fewer riders over the course of a horse's career are for jumping horse’s better variant.

Venous Blood Acid-Base Status in Show Jumper Horses Subjected to Different Physical Exercises

The aim of this study was to assess whether acid-base profile exhibits changes in regularly trained show jumping horses undergoing increasing exercise workloads. Seven female Italian saddle horses were subjected to three different physical exercise trials of increasing workload identified as three exercise phases (EPs). During EPI horses were subjected to a standardized exercise test consisting of 15 minutes of treadmill, during EPII horses were subjected to a show jumping test (height, 0.9–1.1 m; course length, 300 m), during EPIII horses underwent two jumping sessions carried out over two consecutive days. Blood samples were collected at rest (TPRE), after exercise (TPOST), and 30 minutes after the end of exercise (TPOST30). The values of pH, partial pressure of carbon dioxide (Pco2), partial pressure of oxygen (Po2), bicarbonate level (HCO3−), hemoglobin (Hb), and hematocrit (Hct) were measured. A significant effect of exercise workload and time (P < .001) on Po2, Pco2, HCO3−, Hb, and Hct values was found. The variation in the studied parameters resulted mostly reversible within TPOST30 in horses when subjected to EPI and EPII, whereas Po2, Hb, and Hct remained higher at TPOST30 than TPRE in horses when subjected to the second day of jumping section (EPIII) indicating a failure to recover. The results suggest that jumping sessions carried out over two consecutive days represent extra workload for horses, and this should be taken into account by veterinarian to prevent acid-base imbalance and for the maintenance of health and performance in equine athletes.

Thirty-day rhythmicity in electrocardiographic and electrolytic parameters in the athletic horse

This paper describes circatrigintan progress of some electrocardiographic parameters and of the serum electrolytes in the jumper horse during a period of pre-competitive training performed in order to define the temporal organization of some parameters employed to evaluate the athletic performance of the horse. Five Sella Italiana horses, clinically healthy and specifically trained have been utilized for the study. All the subjects have undergone electrocardiographic recordings and blood sample takings by means of jugular venopuncture, at rest and always at the same hour, every five days for a period of one month. The following electrocardiographic parameters have been measured on individual ECG-recordings: P wave duration and amplitude, P-Q interval duration, QRS complex duration, R wave amplitude, T wave duration, S-T segment duration, Q-T interval duration, the longest and shortest R-R intervals; besides, mean R-R interval and D R-R, the highest, lowest and mean heart rate, have been calculated. The concentrations of magnesium, calcium, phosphorus and chlorine and of sodium and potassium have been determined on the blood samples, respectively by UV spectrophotometry and by flaming. The application of a statistic trigonometric model has permitted to point out the circatrigintan periodicity of the following electrocardiographic parameters: P wave duration, T wave duration, R wave amplitude, mean R-R interval and mean heart rate, and of the following serum electrolytes: sodium and magnesium. Based on these results, it is hypothesized that the cardiovascular system follows a “deterministic” progress with a “linear” variability systematically predictable within the temporal period considered.

Iron Metabolism Modification During Repeated Show Jumping Event in Equine Athletes

Abstract In athletic horse the evaluation of iron status is of great importance to improve physical performance and health status of animal. The aim of this study was to evaluate the changes of iron indices following show jumping. Ten regularly trained Italian Saddlebred horses aged 7-8 years (mean body weight 467±12 kg) were subjected to three days jumping competition. Blood samples were collected at 5 time points: T0 (the day before competitions), T1 (immediately after exercise at day 1), T2 (immediately after exercise at day 2), T3 (immediately after exercise at day 3) and during the recovery period T4 (24 h after day 3). On each blood sample the values of red blood cell (RBC), hemoglobin concentration (Hb), hematocrit (Hct), serum iron, ferritin, transferrin, total iron-binding capacity (TIBC) and unsaturated iron-binding capacity (UIBC) were assessed. One-way repeated measure analysis of variance (ANOVA) showed a statistical significant effect of exercise (P&lt;0.05) on all studied parameters. The application of Bonferroni’s post-hoc comparison showed a statistical significant increase in all studied parameters after exercise. These results provide new information about the changes in iron profile of jumper horse following exercise allowing for better evaluation of the health status and physical performance of this athlete horse.

Relationship of Some Oxidative Stress Biomarkers in Jumper Horses After Regular Training Program

In the present study, the redox status of blood samples, by assessing the total oxidant status (TOS), the total antioxidant capacity (TAC), and the oxidative stress index (OSI), together with the nitric oxide radical (NO•) metabolite (NOx) content, was evaluated in trained horses. Moreover, the oxidative damage to lipids and proteins, analyzed as thiobarbituric acid reactive substances (TBARS) and advanced oxidation protein products (AOPP), was also assessed. Twenty-five regularly trained Italian Saddle horses (7–10 year old, 12 geldings and 13 females, mean body weight 480 ± 30 kg) were enrolled in this study. Animals were carried on with their specific training programs for jumpers for 6 days per week with a day of rest, during which blood sampling was performed. On obtained serum samples, TOS, TAC, NOx, TBARS, and AOPP were measured. Our results showed significant linear correlations among markers of redox potential (TAC, TOS, and OSI) and among TOS and NOx with serum markers of lipid and protein oxidative injury (TBARS and AOPP). Furthermore, multiple linear regression analysis has shown that lipid peroxidation and protein oxidation levels are related to the content of oxidant substances (TOS and NOx). The obtained data can be useful to assess the status of an athletic horse and its adaptability to physical effort, providing an opportunity to modify the training schedule to achieve the desired performance.

Application of a combined global positioning and heart rate monitoring system in jumper horses during an official competition - A preliminary study.

The aim of this study was to investigate whether a combined global positioning system (GPS)/heart rate (HR) monitoring system is a valuable tool to assess, step by step, the physiological response of HR and its relationship with speed in healthy horses competing in an official show jumping class. Six mares performing a standardised warm-up and jumping course were monitored using a HR/GPS device. Venous blood lactate (BL), assessed before and after exercise, showed a significant increase (P = 0.0004) following the physical effort. One-way analysis of variance (ANOVA) showed significant changes in HR throughout the experimental period. The analysis of HR data recorded during the warm-up jumping stage showed significantly higher HR (P = 0.001) in the recovery period compared to the related jumping phase. Shifting the fence height from 100 cm to 125 cm during the warm-up jumps was also found to cause a significant increase (P = 0.016) in HR. According to these preliminary results, the simultaneous logging of heart rate and speed has the potential to be a reliable and powerful technique for field testing that can help in the monitoring of the horse's response to jumping effort during training and competition.

Lipid and Lipoprotein Profiles Modification in Athletic Horses After Repeated Jumping Events

The aim of this study was to evaluate the effect of physical exercise on serum nonesterified fatty acids (NEFAs), triglycerides, total cholesterol (total chol), high-density lipoproteins (HDLs), low-density lipoproteins (LDLs), and very low–density lipoprotein (VLDL) fraction levels in Jumper horses. Horses took part to a show jumping competition represented by repeated events. Blood sampling was performed before the first day of competition (T0), within 10 minutes from the end of each competition (T1POST, T2POST, T3POST), and in the day after competition (R1). Statistical analysis showed a significant effect of exercise (P < .001) on all studied parameters. Nonesterified fatty acids showed higher values at T1POST, T2POST, and T3POST than T0. Higher serum triglycerides, VLDLs, and HDLs levels were found at T1POST, T2POST, T3POST, and R1 than T0. Total cholesterol and LDLs values showed a significant decrease at T1POST, T2POST, T3POST, and R1 than T0. The observed changes in lipid and lipoprotein parameters could represent the metabolic response to physical exercise during the 3 days of competition that led to an increase of NEFAs and triglycerides levels after the physical exercise which act as energy support, whereas during the recovery period, the energy production was assured by oxidation of serum triglycerides. The increase in serum HDLs, decrease in total chol, and LDLs point out the positive effects of physical exercise on the lipoproteins profile in trained horses suggesting the reverse cholesterol transport from peripheral tissues to the liver for new biochemical processes in trained Jumper horses.

Feeding Practices and Nutrient Intakes Among Elite Show Jumpers

The objective of this study was to quantify feed and macronutrient intake, as well as generate information regarding nutritional concerns, in 34 elite-show jumper horses. All feed was weighed and used to determine digestible energy (DE), crude protein (CP), Ca, and P amounts offered to the horses daily. Questions to the horse's representative generated information regarding nutrition-related concerns, such as colic or gastric ulcers. Total feed intake averaged 14.9 ± 2.8 kg and was fed at 2.8 ± 0.5% of body weight (BW) on an as-fed basis. The DE offered met 119 ± 4.8% of the National Research Council (NRC) (2007) requirements for a horse at heavy work or 94.2 ± 17% of recommendations for very heavy work. Crude protein offered was also between these two classifications of workload. When expressed on a per kilogram BW basis, DE in the offered diet was 62.5 ± 11.4 kcal/kg BW and CP was 2.0 ± 0.5 g/kg BW. Ca in the diets offered more than two times the NRC requirements, while the diets only contained on average 87% of the NRC P requirements. Nutrition-related concerns were low, in part due to the widespread preventative use of ulcer medications and joint supplements (or injections). Colic concern was also low in this group of horses, despite frequent travel and sudden changes to new feeds. This study highlights a need for horse representatives to be mindful of feed selection when traveling to different venues where different feeds are available.

Increase in erythrocyte osmotic resistance following polyunsaturated fatty acids (PUFA) supplementation in show jumper horses

Osmotic fragility test has been used to study the influence of different factors on the osmotic properties of cell membranes. Considering the importance of polyunsaturated fatty acids (PUFA) in biological functions we aimed to investigate the effects of dietary PUFA supplementation on erythrocyte osmotic fragility (EOF), blood lactate (BL), hematocrit (Hct), red blood cell (RBC), hemoglobin (Hb), and mean cell volume (MCV) in 10 jumper horses. Two events occurred prior to start supplementing horse's diet and two events occurred after 4 weeks PUFA supplementation. Five horses received the PUFA supplementation (Group A), and five served as controls (Group B). Blood samples were taken before and after each course. The statistical analysis revealed significant increase in BL, Hct, RBC and Hb following exercise (P<0.0001). However, the interaction between exercise and PUFA supplementation (P=0.0083) showed PUFA-supplemented horses having a smaller rise in BL levels (P=0.0107) following exercise. Significant interactions between exercise and PUFA treatment were also found on EOF levels (P<0.05). The hemolysis curves showed PUFA-supplemented horses exhibiting a reduction in EOF compared to controls (P<0.05). Although hemolysis never occurred at 0.9% NaCl concentration, jumping exercise determined an increase in EOF (P=0.0014) at 0.8% NaCl solution. A significant interaction between exercise and PUFA treatment (P=0.0022) was found showing PUFA-supplemented horses having lower EOF (P=0.0015) following exercise. The assessment of EOF is a suitable indicator of athletic performance. The results showed that PUFA supplementation might exert beneficial effects on the horse body system by enhancing the performance in high-level show jumpers.

62 Feeding practices and nutrient intakes among elite show jumpers

The objective of this study was to quantify feed and macronutrient intake, as well as generate information regarding nutritional concerns, in 34 elite-show jumper horses. All feed was weighed and used to determine digestible energy (DE), crude protein (CP), Ca, and P amounts offered to the horses daily. Questions to the horse's representative generated information regarding nutrition-related concerns, such as colic or gastric ulcers. Total feed intake averaged 14.9 ± 2.8 kg and was fed at 2.8 ± 0.5% of body weight (BW) on an as-fed basis. The DE offered met 119 ± 4.8% of the National Research Council (NRC) (2007) requirements for a horse at heavy work or 94.2 ± 17% of recommendations for very heavy work. Crude protein offered was also between these two classifications of workload. When expressed on a per kilogram BW basis, DE in the offered diet was 62.5 ± 11.4 kcal/kg BW and CP was 2.0 ± 0.5 g/kg BW. Ca in the diets offered more than two times the NRC requirements, while the diets only contained on average 87% of the NRC P requirements. Nutrition-related concerns were low, in part due to the widespread preventative use of ulcer medications and joint supplements (or injections). Colic concern was also low in this group of horses, despite frequent travel and sudden changes to new feeds. This study highlights a need for horse representatives to be mindful of feed selection when traveling to different venues where different feeds are available.

Right-nostril use during sniffing at arousing stimuli produces higher cardiac activity in jumper horses

Lateralization in horses, Equus caballus, has been reported at both motor and sensory levels. Here we investigated left- and right-nostril use in 12 jumper horses freely sniffing different emotive stimuli. Results revealed that during sniffing at adrenaline and oestrus mare urine stimuli, horses showed a clear right-nostril bias while just a tendency in the use of the right nostril was observed during sniffing of other odours (food, cotton swab and repellent). Sniffing at adrenaline and urine odours was also accompanied by increasing cardiac activity and behavioural reactivity strengthening the role of the right hemisphere in the analysis of intense emotion and sexual behaviour.

Changes of Circulating Total and Free Iodothyronine in Horses After Competitive Show Jumping With Different Fence Height

The effect of exercise on circulating T3, T4, free (f) T3, and fT4 concentrations were studied before and after competitive show jumping in 24 trained jumper horses with an age range of 11–13 years and having the same level of show experience. All horses, randomly divided into three groups paired by gender, participated in three competition levels with the same circuit design over 10 fences, with five upright and five cross-pole fences .The three fence height groups were group I (n = 8), 1.10 m; group II (n = 8), 1.20 m; and group III (n = 8), 1.30 m. Repeated measures analysis of variance showed a statistically significant effect of competitive exercise on fT3 changes in all groups, whereas the effect of competitive exercise on T3 changes was exclusively seen in group III. Two-way repeated measures analysis of variance showed that the effect of fence height (P = .0002) and performance results were significant (P = .0486) only for T3 changes. Performance also affected fT3 changes (P = .0152). No significant correlation was found between total and free iodothyronines. These results suggest a dependence of T3 and fT3 changes on exercise-related variables and performance results and that the thyroid response is different with respect to the different exercise-related variables, such as the varying level of difficulty and performance results.

Some Factors Affecting the Rate of Pregnancy after Embryo Transfer Derived from the Brazilian Jumper Horse Breed

This study aimed to evaluate the effects of certain embryo transfer parameters on the pregnancy rate after equine embryo transfer of the Brazilian Jumper Horse breed. The size, embryonic development stage, embryo quality, and synchronization of ovulation between the donor (n = 120) and recipient (n = 420) were evaluated in 396 embryos. Embryo recovery was performed on Day 6-9 after ovulation (Day 0 = day of ovulation). The recipient mares were chosen on the day of embryo recovery, and the transfers were performed that same day. The embryo size (diameter including envelopes; n = 396) ranged from 150 to 3000 μm; 67.1% measured between 400 and 1199 μm. The embryo size (400-1199 μm vs. ≤399 μm); stage of development (n = 396; blastocyst and expanded blastocyst versus compact morula and early blastocyst); quality (n = 396; grade 1 [excellent]), 2 [good], or 3 [poor]); and synchronization of ovulation between the donor and recipient (0, 1, 2, 3, and 4 days versus −1, 5, and 6 days, respectively) all affected pregnancy rate (P < .05). The pregnancy rate did not differ significantly among transfers performed on Days 0, 1, 2, 3, and 4. In conclusion, embryos measuring 400-1199 μm produced higher pregnancy rates in recipients than embryos measuring 150-399 μm, and blastocysts and expanded blastocysts produced pregnancy more efficiently than morulae and early blastocysts. The embryo quality also affected the pregnancy rate. Synchronization of donor and recipient ovulation to Days 0-4 improved the efficiency of embryo transplant.

Circulating β-Endorphin, Adrenocorticotropin, and Cortisol Concentrations of Horses Before and After Competitive Show Jumping with Different Fence Heights

Circulating β-endorphin, adrenocorticotropin, and cortisol concentrations were studied before and after competitive show jumping in 18 trained jumper horses aged between 11 and 13 years and having the same level of show experience. Horses were subjected to the same type of management and daily training exercise. Each horse had been ridden by the same rider during both the daily training exercise and show jumping event. All horses, randomly divided into three groups paired by gender, performed in three competition levels with the same circuit design over 10 fences, with 5 upright and 5 cross-pole fences, differing for the fence height: group I (n = 6), 1.10 m; group II (n = 6), 1.20 m; and group III (n = 6), 1.30 m. Repeated measures analysis of variance showed a statistically significant effect of competitive exercise on β-endorphin and cortisol changes in all groups, whereas the effect of exercise on adrenocorticotropin changes was exclusively seen in groups II and III. Two-way repeated measures analysis of variance showed that the effect of fence height was significant (P = .03), and time (P = .0001) also affected cortisol changes. These results suggest that the hypothalamic-pituitary-adrenal axis response is different with respect to the different fence heights of jumping course and the different time points of the recovery period.

Effects of competitive and noncompetitive showjumping on total and free iodothyronines, β‐endorphin, ACTH and cortisol levels of horses

Limited knowledge exists about the differentiated effects of competitive and noncompetitive showjumping on thyroid function and relationships with hypothalamic-hypophysis-corticoadrenal hormones. To obtain preliminary data about differentiated effects of competitive and noncompetitive showjumping on total and free iodothyronines, β-endorphin, ACTH and cortisol of horses. Five trained healthy jumper horses were studied during competitive and noncompetitive showjumping, performed in the same circuit design over 10 fences of 1.10 m. Hormone levels before, 5 and 30 min post exercise were recorded. Serum iodothyronines and cortisol concentrations were measured in duplicate utilising EIA kits. Serum ACTH and plasma β-endorphin concentrations were analysed in duplicate utilising RIA kits. Two-way RM ANOVA was applied to test for effects of interaction between different type of session and time. Significant differences between post exercise and basal values were established using Bonferroni's multiple comparison test. A linear correlation analysis (Pearson's method) was performed to analyse the relationships between total and free iodothyronines and between iodothyronines and β-endorphin, ACTH and cortisol. In sampling times adopted no statistical different effects of type of session were recorded on hormone variables. Sampling time affected ACTH (F = 4.25; P < 0.02) and T(4) (F = 4.43; P < 0.02) post exercise changes. During the noncompetitive session, significant correlations existed between T(4) and β-endorphin (r = -0.56), ACTH (r = -0.65), between β-endorphin and ACTH (r = 0.52) and between T(3) and fT(3) (r = 0.72); during competition between β-endorphin and T(3) (r = -0.67), fT(3) (r = -0.59). These preliminary results could demonstrate correlations between thyroid hormones and β-endorphin response to showjumping, although no definitive conclusion can be produced concerning the relationships between HPA and thyroid function during exercise.

The Effect of Aerobic Exercise on Intraocular Pressure in Horse

The present study was planned to investigate the effect of the intensity of exercise on intraocular pressure (IOP), systolic and diastolic blood pressure, glycaemia and blood lactate concentration in regularly trained Italian saddle jumper horses. On the first day five female horses performed 1 h of walking on an electronically controlled horse-walker at 100 m/min; on the second day 1 h session consisted of 5 min of walk, 30 min of trot, 20 min of gallop and one exercise of a 300 m long trail with eight jumps 90 cm high to be run in 1 min. The studied indicators were collected at rest, immediately after the exercise and 30 min after the exercise. Analysis of variance (ANOVA) showed a significant effect of different workloads on blood lactate concentration, systolic and diastolic blood pressure. No significant difference was found in IOP reduction when comparing aerobic and moderate anaerobic exercise. Our results confirm that the lack of a significant change in IOP in the athletic horse after mild exercise is in accordance with the human athlete. The cardiovascular and haematological changes induced by aerobic and moderate anaerobic exercise had no significant effect on IOP, either.

Serum electrolyte and protein modification during different workload in jumper horse

Five clinically healthy Italian saddle horses were used to assess serum electrolyte and protein modification during different workloads. Blood samples were collected from each horse at rest, immediately after each exercise and at 30 and 60 min after the end of exercise. Our results confirm that exercise has variable effects, depending on work intensity, on some electrolytes, total protein and haematocrit. Based on our results, it is possible to affirm that the studied indices could be useful in the assessment of the fitness of sport horses and that it is appropriate to correlate these electrolytic modifications to blood density.

Bilateral nodular lymphocytic conjunctivitis in a horse

A Russian jumper horse presented because of an ocular perilimbal conjunctival mass and, on clinical examination, two bilateral conjunctival masses were found, of different size and conformation. Attempts at complete excision of the left eye mass and excisional biopsy of the right eye mass were performed. The left eye mass recurred rapidly, but resolved completely after topical corticosteroid therapy. The two lesions had similar histopathologic features, characterized by focal, chronic, primarily lymphocytic conjunctivitis with follicular lymphoid hyperplasia. Special histopathologic staining techniques (Gomori methenamine silver and acid fast stains) and immunohistochemistry (for CD3, BLA36 and lysozyme) failed to reveal any etiologic agents and indicated an inflammatory lesion composed of a heterogeneous population of lymphocytes and macrophages (nodular lymphocytic conjunctivitis). The lesions were indistinguishable, clinically and behaviorally, from what has been reported as 'conjunctival pseudotumor' in the horse. Equine conjunctival pseudotumor/nodular lymphocytic conjunctivitis has been reported to be unilateral and have a good prognosis after partial or complete surgical excision. This is the first reported case of bilateral nodular lymphocytic conjunctivitis in a horse and for which surgical excision alone was not curative.