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Regular exercise testing in Warmblood sport horses may, as in racing, potentially help to characterise fitness indices in different disciplines and at various competition levels and assist in understanding when a horse is 'fit to compete'. In this review an overview is given of the current state of the art of exercise testing in the Olympic disciplines of eventing, show jumping and dressage, and areas for further development are defined. In event horses, a simple four-step incremental exercise test measuring heart rate (HR), lactate concentration (LA) and velocity (V) is most often used. In dressage and riding horses, a wide variety of exercise tests have been developed, including incremental exercise tests, indoor riding tests and lunging tests. In show jumping, the use of a five-step incremental exercise test and exercise tests evaluating technical skills and fatigue of the horse has been reported. The velocity at a plasma LA of 4 mmol/L (VLA4) and HR recovery during submaximal exercise intensity have been shown to be the best parameters in event horses for predicting performance and impending injuries. In riding horses, the fitness level of horses is also an important determinant of injuries. Implementation of regular exercise testing and monitoring of training sessions may have important added value in the assessment of performance ability and potential future injuries in Warmblood sport horses. However, there is an urgent need to standardise methodologies and outcome parameters in order to make results comparable., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The aim of this study was to monitor the fitness level of young Friesian horses and to assess whether fitness data are predictive for final performance score and whether familial aggregation of response to training could be detected. Sixty-six young Friesian horses, the offspring of six different stallions (A, B, C, D, E and F), underwent a 7-week performance test. The horses were given a performance score for their ability for dressage (in weeks 5 and 7; 0-110 points) and were evaluated for fitness using standardised exercise tests (SETs) at the beginning (week 2, SET-I) and the end (week 6, SET-II) of the period. Heart rate (HR, beats/min) was measured in both SETs, and plasma lactate concentration (LA, mmol/L) was measured only in SET-II. Fitness of the horses improved moderately but significantly between SET-I and SET-II (P=0.015). There was a large heterogeneity in responsiveness to training; some horses were high responders, whereas others were non- or low responders. There was a familial aggregation of HR canter-1 response to training (P=0.039), while the HR of stallion C's offspring decreased significantly more than those of stallions A (P=0.09), D (P=0.013) and F (P=0.009). Horses that were reluctant to exercise did not differ in HR or LA concentrations compared to those that completed the SET, which may have been a sign of overreaching. HR had no predictive value for the performance score, but horses that did not reach the anaerobic threshold in SET-II scored significantly better (73.8 ± 5.6 points) than horses that did not (69.9 ± 5.9 points, P=0.025). The findings demonstrate for the first time in the horse a familial aggregation of HR response to training, as has been reported previously in humans. Familial aggregation suggests a genetic influence on the effect of training on fitness in horses. HR could not predict final performance score, but LA concentrations during SET-II were predictive., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

A single dose of 40 μg/kg bodyweight (BW) of oromucosal detomidine gel was administered sublingually to 10 healthy Dutch Warmblood mares aged 7 ± 4 years (mean ± SD) and BW 580 ± 69 kg. Blood and urine samples were collected before and for 8 days following administration and evaluated qualitatively in an FEI Reference Laboratory and quantitatively in a research laboratory. Clinical effects were evaluated at baseline and for 24 h after administration. Sedation was determined using head height and scores of reaction to auditory and mixed auditory/sensory stimuli. Mechanical nociceptive thresholds (MNTs) were assessed using pressure algometry to evaluate analgesia. Heart rate (HR) was measured and ataxia scored. All horses were considered negative for detomidine in blood samples by 48 h post-administration and in urine by 60 h. These results indicated that a safe withdrawal time for detomidine oromucosal gel may be 72 h following a single sublingual administration of 40 μg/kgBW. Decreases in HR and head height were maximal at 40 and 60 min post-administration, respectively. The maximal decrease in response to stimuli was observed at 100 min. Ataxia was maximal at 60 min. At 40 and 80 min MNTs were significantly increased compared to baseline. All parameters, except the MNTs of two locations, which were decreased, returned to baseline values within 24 h post-administration., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Equine piroplasmosis (EP) has not been considered indigenous in The Netherlands. However, following the detection of an apparently indigenous subclinical Babesia caballi infection in a horse on Schouwen-Duiveland (an island in the Zeeland Province), a survey was undertaken between May and September 2010 to assess the prevalence of the causative agents of EP in the South-West of The Netherlands. Blood samples from 300 randomly selected horses were tested for specific antibodies against Theileria equi and B. caballi using an indirect fluorescence antibody test (IFAT), and for parasite DNA using a specific polymerase chain reaction combined with reverse line blotting (PCR-RLB). Twelve of the horses (4%) were seropositive for EP. Of these, nine (75%) were positive (titre⩾1:160) for B. caballi alone and three (25%) were also positive for T. equi. PCR-RLB detected T. equi DNA in five horses (1.6%), two of which were seronegative. Four (1.3%) of the positive horses (three positive for T. equi and one for both B. caballi and T. equi) were considered truly indigenous. During the study, two indigenous ponies from a farm situated outside the sampling area were diagnosed with acute clinical piroplasmosis characterized by severe anaemia and pyrexia. Blood smears showed T. equi - like inclusions in red blood cells, and T. equi infection was confirmed in both ponies by PCR-RLB. The initial subclinical B. caballi infection, the survey results and the two acute clinical EP cases confirmed the autochthonous transmission of B. caballi and T. equi infections in The Netherlands., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

A good horse-rider 'match' is important in the context of equine welfare. To quantify the influence of repetition and horse-rider matching on the stress of horses encountering challenging objects, 16 Warmblood horses were ridden in a test-setting on three occasions. On each occasion the horse was ridden by a different rider and was challenged by three objects (A-C). Heart rate (HR), heart rate variability (HRV) of horse and rider, and behaviour score (BS) of the horse were obtained for each object and as a total for each test. The horse-rider interaction was evaluated with each combination and assessed as 'matching' or 'mismatching', and the horses were categorised as 'compliant', 'partly-compliant' or 'non-compliant'. Horses exhibited a decreased HR (P=0.015) and a decreased BS (P=0.004) within and across different tests. 'Matching' horse-rider combinations exhibited less stress as indicated by reduced HR ('match' 69±10 vs. 'mismatch' 72±9, P=0.001) and BS ('match' 1.9±1.1 vs. 'mismatch' 3.8±1.4, P=0.017) of the horse. 'Compliant' (68±8, P<0.001) and 'partly-compliant' (71±9, P=0.002) horses had significantly lower HR than 'non-compliant' (75±9) animals. The findings of the study indicate that HR and BS measurements support a subjective 'match' diagnosis and HR measurement may be a valuable tool in assessing horse compliance., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Culicoides spp. act as vectors for a number of viral diseases of animals including bluetongue in sheep. The aims of this study were to determine: (1) which Culicoides spp. are associated with sheep in The Netherlands; (2) the time of the day when they are most active; and (3) the effect of treatment of animals with a permethrin insecticide. Two pairs of sheep were each housed within mosquito tents of either one or two layers of netting and all trapped Culicoides spp. were identified microscopically. For the permethrin insecticide study, one of two pairs of sheep was treated with 3.6% permethrin and all animals were housed in tents of similar design. Of the 6210 midges captured, 54.1% were identified as C. chiopterus and 42.7% as C. obsoletus. C. imicola was not identified. The average insect feeding rate was 35-40% and midge activity was greatest around sunset. Permethrin treatment reduced the number of midges captured by 50% and also resulted in a decrease in the percentage of midges that had fed. The findings provide useful information on the behaviour and distribution of Culicoides spp. that will facilitate the development of appropriate control strategies to minimise the risk of insect-vector borne virus diseases such as bluetongue., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Equid herpesvirus type 1 (EHV-1)-associated myeloencephalopathy (EHM) may follow an infection with the virus in horses. This study tested three hypotheses: (1) a large inhaled dose of a neuropathogenic EHV-1 strain would induce a cell-associated viraemia in all infected horses; (2) neurological disease will only occur in viraemic horses, and (3) the cerebrospinal fluid (CSF) composition following EHV-1 viraemia will be an indicator for EHM. Four EHV-1 seronegative horses were inoculated with EHV-1 by inhalation. Three developed clinical signs of neurological disease, which were mild in two horses and lacking typical EHM histopathological findings, but moderately severe in the third horse. This latter animal was the only one found to be viraemic, with xanthochromic CSF and spinal cord histopathology findings characteristic of EHM. This study showed that cell-associated viraemia was not guaranteed, despite a large-dose inoculation with EHV-1, yet viraemia was probably a pre-requisite for subsequent development of EHM. The histopathological changes used to confirm EHM may be predicted from CSF analysis., (Copyright © 2009 Elsevier Ltd. All rights reserved.)

Measuring the height of ponies at the withers is currently a prerequisite at Fédération Equestre Internationale (FEI) competitions. A pony measured at a competition site must not measure more than 151 cm with, or 150 cm without horse shoes. When a pony exceeds the regulated height, it is excluded from participation in the competition. Moreover, the sale value of a pony can decrease dramatically if by height measurement it is designated as a 'horse'. The aim of this study was firstly to determine whether measuring ponies at the withers with a laser device is repeatable; secondly, to evaluate whether laser measurements are more accurate than use of a conventional measuring stick, and, thirdly, to evaluate the difference in height at the withers between ponies at home and the height of the same ponies at a competition. Fifteen clinically healthy horses and 38 healthy ponies were used in the study. A statistical evaluation was performed to determine whether there was a correlation or a significant difference between measurements (P<0.01). The repeatability of the laser measurements, the comparison of the use of the laser versus the measuring stick, and of the measurements done at home compared to the competition site were all very high (0.999, 0.0997 and 0.992, respectively; P<0.01). The mean height measured at a competition was 141.9+/-9.0 cm and of the same ponies at home was 142.4+/-9.1 cm. This difference was not significantly different, although there was a tendency for ponies measured at home to have a higher height at the withers compared to the same ponies at a competition.

Measuring the height at the withers of a pony is one of the requirements of the Fédération Equestre Internationale (FEI), before competitors can participate in an official pony event. A pony has to be measured each year until it is eight years old. With and without shoes the height at the withers must be below 149.0cm and 148.0cm, respectively. When a pony exceeds the regulated height, it is excluded from participating in FEI pony competitions. Besides being excluded from competing, the selling price of the pony decreases dramatically, because the animal is then classified as a horse. For these reasons some owners may be tempted to try to influence wither height. The aim of the study was to determine whether the height of a pony at the withers can be influenced by variables such as time of day, water and feed withdrawal, weight carrying, exercise or sedation. To see if there was any influence of these variables on the measured height, the animals were measured at the beginning of the experiment and after completion, according to a standardized protocol. Fifteen healthy horses aged 7-17 years old and 16 healthy ponies aged 5-18 years were used for the study. A statistical evaluation determined whether there was a significant difference between the height at the withers before and after the experiment (P<0.05). Time of day, water and feed withdrawal, carrying weight, exercise and sedation all tended to decrease the height at the withers, but, with the exception of the data collected from the sedation-trial, the results were not significant. At the beginning of the experiment, the mean height at the withers of all eight animals was 165.0+/-4.6cm; 15min after giving a standard dose of 5microg/kg detomidine-HCl per horse IV, the mean height had decreased to 163.7+/-4.5cm. Even 2h after administration of the sedative, the mean height at the withers was still 163.7+/-4.6cm. However, at both measuring points, it was still clinically apparent that the animals were sedated. The results demonstrate that it is not possible for owners to significantly influence the height at the withers except by administrating a sedative.