Animal Health Trust surveys Endurance GB members and riders on all aspects of the sport.
Words by Annamaria Nagy
British Endurance Health Survey Results – Summary and discussion
In 2015, 1209 horses were registered with Endurance GB and the main riders of all of these horses were eligible to participate in the study. In total, 258 responses were received. After exclusion of incomplete surveys, a complete dataset was available for 190 horses. Therefore the response rate for completed datasets was 15.7%. Although the completed surveys provided very valuable descriptive data, numbers were not high enough for robust statistical analysis (e.g., to investigate risk factors for specific veterinary problems).
Details on riders and horses
Over 90% of respondents (riders) were female. Nearly 89% of Endurance GB members are female; therefore the respondents’ gender distribution is a good representation of Endurance GB members. The average age of the riders was 45.8 years (range 14-70). No precise age data of Endurance GB riders are available. The average rider weight was 66 kg (range 42-101 kg). While a large proportion of riders (69%) had experience in rides of 80 km or longer distance, only 32% had participated in FEI rides.
The majority of horses (97%) had been ridden by the current rider for longer than a year; therefore the riders were expected to have good knowledge of their horses which was useful for our study. The average age of horses was 13 years (range five to 26), which is a relatively high average age for competition horses. It is possible that endurance horses compete until late in their lives, therefore increasing the average age, but it is also possible that horses start their endurance career late. The average age of all horses registered with Endurance GB is also 13 years. Sixty percent of the horses were geldings, 39% mares and there were three stallions. Nearly half of the horses were pure-bred Arabians and a further 18% were Arabian cross breeds. Other common breeds were Cob-type and Warmblood. The average weight of the horses was 460 kg (range 300-733 kg), however, these data have to be interpreted with caution because the weight of only 26% of horses had been established using a weighbridge (and therefore can be considered accurate). The average height of the horses was 153 cm, approximately 15.1 hands (range 109-175 cm).
The riders’ weight was expressed as a percentage of the horse’s weight: the average value was 14% (range 7-21%). More than one-third (37%) of riders weighed more than 15% of their horse’s bodyweight. Ideally a horse should carry a rider who weighs no more than about 15% of the horse’s bodyweight. Although to date no studies have been done in endurance horses, weight may play an even more important role in the horse’s welfare than in other disciplines as horses carry this weight over long distances during several hours. The horse’s build, strength, training and fitness level are likely to contribute to the horse’s weight carrying capacity. The length and difficulty of the ride (e.g., due to difficult terrain) can also influence how much weight the horse can carry without compromising welfare.
Competition record
During the 2015 season, nearly half of the horses participated in at least six endurance rides. Data on participation in an endurance ride, and not on the number of completed rides, were collected; therefore data on total mileage, either in competition or in training, were not available. In the future, it would be very valuable to collect data on completed competition and training miles and to investigate association with performance and veterinary problems. In 2015, 31% of horses were eliminated for lameness, less than 4% for metabolic reasons and 7% for other reasons. In the largest epidemiological study on elimination from endurance rides that evaluated 30,741 horse starts in 47 countries, 30% of all started horses were eliminated for lameness and 9% for metabolic reasons.
It is important to note that in the above mentioned study eliminations were expressed as a proportion of horses that started an endurance ride, while in the current study horses that had yet not competed were also included. Moreover, in the previous study only FEI rides were included and in the British Endurance Health survey both national and international rides were included. Therefore numbers are not directly comparable, but the quoted study may help to put results into perspective.
Husbandry and nutrition
More than half of the horses were kept on small yards of two to five horses and only 7% were kept on a yard with more than 20 horses. The majority of horses were turned out for at least half of the day over the entire year. Most horses were turned out on grass fields all year round; the ground was mostly soft or deep in winter and mostly hard or soft in summer.
Fresh grass, grass hay and haylage were the most commonly used forage types all year round. For the majority of horses (96% in the competition season and 86% in the off season) grazing was an important part of their diet. All horses received at least one type of forage and 83% received two or more different types of forage.
More horses received concentrates in the training and competition season than in the off season. Concentrates included sugar beet, mix, oil, nuts, grain, linseed and copra meal, where the most commonly used concentrate is listed first and the least commonly used last. The majority of horses received at least one type of supplement. The most commonly used supplements included salt and composite electrolytes, balancer and joint supplements (in decreasing order). In the competition season nearly two-thirds of horses received daily salt or composite electrolyte supplements in feed or in a paste. Significantly fewer horses (14%) were fed electrolytes in the off season period. The rider’s experience was significantly associated with feeding electrolytes in the competition season and on the day of the ride; horses belonging to riders that had competed in distances of 80 km or more were significantly more likely to receive electrolytes than horses of riders who had only competed in distance categories of shorter than 80 km. Horses can lose a considerable amount of electrolytes with sweat, mostly sodium and chloride which are the composite of simple salt, therefore it is important that their daily diet contains a sufficient amount of these basic electrolytes. Feed and diet analysis by a nutrition consultant, taking into account training duration and intensity, can help to establish how much electrolytes a horse should be fed on a daily basis.
Training
Approximately 80% of horses were ridden by only one rider. The majority of horses (96%) were ridden one to five times a week. For more than half of the horses, the longest training session of the week included trotting for a total of 30-59 minutes and cantering for less than 30 minutes in total. The duration of the longest trotting and canter sessions, or the distance of the longest training session, was not associated with the horse’s previous competition experience. It is likely that riders follow many different training strategies and numbers in this survey were not high enough to allow for detection of patterns.
It appears that the majority of horses were ridden less frequently than horses from other work disciplines. Inadequate fitness level in endurance horses might contribute to orthopaedic injury and lameness. Although it is generally believed that inadequate fitness can increase the risk of orthopaedic injuries, no evidence-based study has proven this association in horses. From the current dataset no conclusions on fitness for a specific competition can be drawn. Only collection of daily training data, including distance and speed in each gait, in preparation for a competition would allow appropriate assessment and analysis of potential fitness for a ride of specific speed and distance.
The majority of horses did some canter work as a part of their training. The distance the horse had competed in during 2015 was not associated with canter work; i.e. there were horses competing in all distance categories, including rides of over 130 km distance, that did not complete any canter work as part of their training preparation. Most horses did canter work one to three days a week and the most common canter distance was one to three miles. The speed of the fastest canter work of a typical week varied greatly. Riders that had competed in longer rides were more likely to canter their horses faster and for longer distances in training than riders competing in shorter rides. The rider’s experience was not associated with the frequency of canter work. Interestingly none of the canter work parameters were associated with the horse’s previous experience. Interval canter work was part of the training of the majority (85%) of horses. The terrain on which regular endurance training was performed varied greatly. The most common going horses were trained on was a mixture of hard and soft. Most horses were regularly ridden on asphalt (other than road crossings), the majority of them at the trot.
Only 10% of horses used a horse walker on a regular basis. Approximately 59% horses were lunged as a part of training; the majority of them once or twice a week. Nearly two-thirds of the horses were lunged with a training aid. Approximately half of the horses were schooled regularly. The most common arena surface was synthetic; followed by sand, grass and woodchip. Two-thirds of the horses were schooled for 31-45 minutes per occasion.
In preparation for a ride, the distance of the longest training session was 25-75% of the ride, regardless of the distance of the competition. With increasing ride distance, a significantly greater proportion of horses were trained for a relatively smaller distance in relation to the distance of the ride. With regards to a rest period after endurance rides, most horses had 1-3 or 4-7 days off training after a ≤40 km ride; 4-7 days off after a 41-79 km ride; and 8-14 days off after an 80-100 km ride. For longer distances, the rest period varied greatly among horses and ranged from four to more than 28 days or longer. These rest periods indicate the time without strenuous exercise and not the time before entering the next competition. For reference, the current compulsory rest periods after an FEI ride before entering the next national or FEI ride are as follows: start to 40 km: 5 days; start to 80 km: 12 days; over 80-120 km: 19 days; over 120 -140 km: 26 days; over 140-160 km: 33 days.
The length of the off season period, that of rest and light exercise between the training and competition seasons, varied among horses and was not associated with the level (distance) of competition in which horses participated in 2015. The greatest proportion of horses was rested for one to two months; 23 horses were not rested at all and only two horses were rested for more than four months. Nearly 40% of horses were trained in disciplines other than endurance. The most popular discipline was dressage, followed by show-jumping.
Tack
Most horses were trained in an endurance or general purpose saddle. Surprisingly, less than one third of the responders knew the weight of the saddle and numnah; the average weight of the saddle and numnah together was 8 kg (range 3-15 kg). The weight of the saddle is obviously contributing to the carried weight in training and riders competing in CEI*** have minimum weight requirements meaning lighter riders may have to carry extra weight.
The saddle had been fitted to over 90% of horses and 71% of these fittings had been carried out by a professional saddle fitter (member of the Society of Master Saddlers or the Society of Master Saddler Fitters Consultants), which is reassuring. However, less than half of the horses had their saddle fitted in the last six months and in 26% of saddle fittings ridden assessment was not carried out. We know from research that the shape of the horse’s back can change in as little as two months. This change can be marked when considerable increase or decrease in the workload is made and in young horses when they start training. Therefore it is recommended that when a horse is in training, the fit of the saddle should be checked every three months. Ridden assessment is a crucial part of saddle fitting; the saddle has to fit both the horse and the rider and with the rider in place, the saddle can be in a different position in relation to the horse. In endurance horses finding and fitting a saddle that fits both a relatively small and lean and often short-backed horse (i.e. a typical fit endurance horse) and even an average size rider can be challenging. Moreover, endurance horses carry the saddle for a much longer period of time than horses in other disciplines, therefore an ill-fitting saddle is expected to have a great impact and potential detrimental effects, such as sores and muscle pain and even gait abnormalities.
More than two-thirds of horses were trained in a synthetic endurance bridle; for the rest of the horses a leather bridle was used. The majority of riders used the same saddle and bridle in competition as in training. Approximately one-fifth of horses showed adverse behaviour when being tacked up. The most common symptoms included turning their ears back, biting, kicking, moving back in the stable and taking short steps when mounted. Although adverse behaviour when tacking up is not always pain-related, it can indicate pain due to an ill-fitting saddle or other medical conditions, such as gastric ulceration.
Shoeing
Most horses (84%) were shod in the training and competition season, the majority of them on all four feet and at a frequency of four to six weeks. Stainless steel shoes were used for the majority of horses. In competition, pads were used on the front feet of 28% of horses and on the hind feet of 14% of horses. Considerably fewer horses were trained with pads.
General veterinary care
More than two thirds of the horses underwent routine veterinary health checks to check the health status of the horse, not for specific veterinary problems, and the majority of horses also underwent routine dental checks performed either by a veterinary surgeon or by an equine dental technician. More than half of the horses received regular physiotherapy assessment and/or treatment.
The most common veterinary problems
Lameness was by far the most common veterinary problem. This is in agreement with studies in other equestrian disciplines; however, the prevalence of lameness in endurance horses seems to be much higher than in dressage horses or elite show-jumpers. In a study investigating veterinary problems in dressage horses using an owner-based questionnaire 33% of dressage horses had been lame at some point during their career and 24% of these within the previous two years. In the current study 80% of endurance horses had been lame at least once in their career and more than half of all horses had experienced multiple episodes of lameness. In the 12 months preceding completion of the survey, more than half of the horses had suffered from at least one episode of lameness. Forty percent of horses had been eliminated for lameness from an endurance ride at some stage during their career.
The speed of the fastest canter work in training was associated with lameness: horses that cantered at 20.1-25 km/hr were more likely to have been lame in the past 12 months than horses that cantered slower than 20.1 km/hr or faster than 25 km/hr. Interestingly the group that was the least likely to have suffered from lameness in the past 12 months was that whose training included canter work faster than 25 km/hr. No conclusions can be drawn from these results because the sample size was small and likely there were other contributing factors. Further studies are needed to assess the association between the speed of canter work and injuries.
Horses that underwent dressage training were more likely to have gone lame in the past 12 months than horses that did not receive dressage training. Dressage training may have exposed horses to additional strains resulting in lameness, but it is also possible that horses that had gone lame received dressage training following the lameness episode. It is also possible that working in circles during dressage training made lameness evident, which might have not been noted during endurance training.
Back pain was the second most common veterinary problem. Despite 35% of horses having suffered from back pain, in only three horses did back pain result in elimination from an endurance ride. This suggests that in most horses back pain appeared during training. Horses that had their saddle fitted in the last six months were more than twice as likely to have had back pain than horses whose saddle had been fitted over six months ago. This most likely reflects that attention was paid to the saddle in horses that had been diagnosed with back pain. Interestingly, increasing horse age slightly decreased the risk of back pain. It is possible that horses with more training and experience have better developed muscles in their backs that can help to prevent back pain. The number of horses suffering from other conditions was too small for meaningful statistical analysis.
Non-specific cough was the third most common veterinary problem, followed by skin disease, colic, rhabdomyolysis (tying up), heart murmur, viral respiratory infection and diarrhoea. Other, less commonly diagnosed veterinary conditions affecting <5% of horses included muscle disease other than rhabdomyolysis (tying up), gastric ulcers, laminitis, cardiac arrhythmias, nose bleed, recurrent airway obstruction (heaves, COPD), respiratory noise and synchronous diaphragmatic flutter.
The most recent episode of lameness
Information on the most recent episode of lameness was available for 147 horses. In more than half of these horses the most recent episode of lameness resulted in elimination from an endurance ride. The most commonly identified lame limbs were the left forelimb and the right hindlimb, followed by the right forelimb and left hindlimb. Most horses were lame on one limb and nine horses were lame on two limbs. In seven horses the lame limb was not identified or the rider did not remember.
Approximately 76% of these lameness episodes were recognised by a veterinary surgeon, which included detecting lameness at the vet gate at an endurance ride. Lameness investigation was performed in only about half of the recent lameness episodes. Immediate veterinary consultation was sought in only one-fifth of cases. The rest of the horses were rested before the veterinary assessment, approximately half of them for up to two weeks and the remaining 28% for more than two weeks. The urgency of seeking veterinary advice may have been influenced by the severity of lameness. Joint or nerve blocks (diagnostic analgesia) were used in a surprisingly low number of lameness investigations (22%). Although there are many causes of lameness that can be diagnosed without blocks (e.g., nail prick, bowed tendon), diagnostic analgesia is often the only way to be sure about the site of pain even if apparently obvious clinical signs (e.g., swollen joint) are present.
The most common veterinary diagnosis of lameness was tendon or ligament injury, followed by joint pain, which included both acute and chronic injuries. Foot pain was also common; mechanical foot pain included farriery-related issues (e.g., nail prick) and bruises. Other diagnoses included sacroiliac pain in two horses and stress fracture of the proximal phalanx (long pastern bone) in one horse. A variety of treatments were used, including painkiller medication, physiotherapy, joint injection, remedial farriery, shock-wave therapy, chiropractic treatment and surgery. In more than half of lameness cases diagnosed by a veterinarian, no treatment was used. Sixty percent of horses had less than a month off training due to the most recent episode of lameness. A large proportion (25%) of horses had to undergo a prolonged rest; half of these for longer than six months.
Some orthopaedic problems resolve without diagnosis and appropriate rehabilitation and treatment; however, recurring lameness is seen in an alarmingly high number of endurance horses; as seen above, more than half of the horses had suffered from multiple episodes of lameness. Although in the current study it was not possible to establish what proportion of multiple episodes had been caused by the same underlying problem, experience of endurance rides suggest that there are many horses that get eliminated for lameness on the same limb on multiple occasions. In many endurance horses, lameness only presents after a long distance (i.e., in competition) and relatively quickly improves with rest, only to recur when the next long distance is completed (i.e., the next endurance ride). Therefore, unless there is a convincing obvious cause of lameness, such as a foot abscess, it is advised that veterinary attention is sought as soon as possible after the lameness is noted and that a detailed lameness investigation is requested.
Stones and lost shoes are often blamed as a cause of lameness in endurance horses and while they can certainly cause lameness, it is better to seek veterinary advice to ensure there is no other injury, unless the horse becomes completely sound after removal of the stone or replacement of the shoe. Early investigation allows accurate diagnosis and appropriate treatment, and can determine the appropriate rehabilitation period and prognosis, thus prolonging the working life of endurance horses and avoiding the frustration, wasted money and finances caused by recurrent lameness and eliminations.
The most recent episode of back pain
Detailed information on the most recent episode of back pain was available for 56 horses. In three of these horses (5%) the most recent episode of back pain resulted in elimination from an endurance ride; in the majority of horses back pain was first noted in training. The most recent episode of back pain was most frequently recognised by a physiotherapist and by the rider; a diagnosis was made by a veterinarian in only 18% horses. Veterinary investigation of the back pain was carried out in only 27% horses. Veterinary diagnoses included back pain related to an ill-fitting saddle, muscle pain, kissing spines, spondylosis and osteoarthritis of the facet joints in the back. The most commonly used treatment of back pain was physiotherapy, followed by chiropractic treatment and fitting or changing the saddle. Sixty percent of the horses had up to two weeks off training, 15% had more than two weeks but less than four weeks off, 9% had one to two months off and the remaining horses more than two months.
Back pain often develops as a consequence of hind limb lameness. Therefore, unless there is a very obvious cause of back pain (e.g., saddle sore), an underlying, often subtle, hindlimb lameness should be ruled out. The rider’s position should also be evaluated because asymmetric riding, the ‘crooked rider’, can also contribute to back pain, especially when horses are ridden for a long period of time. As mentioned before, the fit of the saddle should be checked during the training season as the shape in the horse’s back may lead to discomfort and back pain if the saddle is not adjusted accordingly.
The most recent episode of colic
Detailed information on the most recent episode of colic was available for 21 horses. In one horse the last episode of colic resulted in elimination from an endurance ride. In two-thirds of the horses a diagnosis of spasmodic colic was made; other diagnoses included impaction and uterine infection resulting in colic symptoms. In five horses no specific diagnosis was achieved. Most horses were treated with medication (e.g., pain killers and fluids) and four h
In a previous study the most common cause of colic occurring during or shortly after an endurance ride was paralytic ileus, or lack of movement of the guts. The results of the current study are more likely to reflect colic in the general horse population, and not only endurance horses, because in the majority of horses colic was not related to an endurance ride.
The most recent episode of rhabdomyolysis (tying up)
Detailed information on the most recent episode of tying up was available for 20 horses. In 30% of horses the last episode of tying up resulted in elimination from an endurance ride. In seven horses the last episode of tying up was related to an endurance ride: three horses tied up during the first half of the ride, one during the second half of the ride, two immediately after the finish and one not immediately, but within 12 hours of finishing the ride. The urine was discoloured in two-thirds of horses. Six horses presented with mild stiffness, 13 horses were moderately stiff and unwilling to move and one horse was recumbent (lying down), unable to move. Historically tying up was related to working after a day of rest, during which day off the horse had been eating and was loaded with carbohydrates. The pathophysiology of tying up is likely much more complicated than that and there is a lot we still do not know. Generally speaking, at endurance rides we see two clinical manifestation of tying up. Some horses develop symptoms in the first loop, often within the first few kilometres of the ride. These horses are often excitable, some had not drunk much the night before and some are ridden too fast for their level of fitness. Another group of horses develop signs of tying up towards the end of the ride and most of these horses are also metabolically compromised, or in other words, exhausted.
A blood test, including measurement of muscle enzyme activity, was used and confirmed the diagnosis in two-thirds of horses and muscle biopsy was performed in one horse. In most horses blood tests are not needed for diagnosis, and muscle enzyme activity levels often do not correlate well with the severity of clinical signs, but it is helpful to establish baseline levels in order to monitor recovery. Half of the horses received medication (e.g., pain killers), two horses received intravenous fluids and medication and 40% recovered without treatment. If an endurance horse ties up during a ride or after a long training session, or there is evidence of dehydration, even after a very short distance, intravenous fluids are recommended to aid recovery. The breakdown products of muscle injury can potentially damage the kidneys and fluids can help to reduce this risk by ‘flushing the kidneys’.
Most horses had less than one month off work due to the most recent episode of tying up, but horses with more prolonged symptoms had prolonged rest. Blood tests to measure muscle enzyme activity are helpful to guide when horses can return to training; generally the aim is for the muscle enzyme levels to return to normal before ridden exercise is introduced. If possible, horses should be turned out during convalescence and be encouraged to move around. Replacing at least some of the carbohydrates with oil may help to reduce the chance of future episodes of tying up.
Further research studies in endurance horses are needed to investigate whether there is an underlying cause (e.g., genetic muscle disorder) that may make certain horses more prone to tie up.
Conclusions
The most common veterinary problem was lameness, affecting the majority of endurance horses at some point of their careers. A surprisingly low proportion of lameness episodes were investigated by veterinary surgeons despite the high proportion of horses affected by lameness and the proportion of horses with recurrent lameness episodes. The second most common veterinary problem was back pain, followed by non-specific cough, skin disease and colic. Lameness and rhabdomyolysis (tying up) resulted in longer time off training than back pain and colic. Data on a larger number of horses are needed to assess risk factors for specific veterinary problems in endurance horses.
For further reading on the survey results, including statistics and charts, please visit the Endurance GB Blog pages online at http://endurancegb.co.uk/main/Blog
If you would like more information or would like to discuss any of the results directly with the author, please email Annamaria on annamaria.nagy@aht.org.uk
