Non-elite Grand Prix dressage horses assessed at two British competitions had a higher frequency of low-grade lameness and canter abnormalities than their World Cup counterparts, researchers report.
They were also more likely to incorrectly perform many of the movements requiring collection than their World Cup counterparts.
Leading lameness researchers Sue Dyson and her colleague Danica Pollard had expected to find higher levels of low-grade issues among the non-elite horses when compared to assessments of the dressage horses at World Cup level.
In a study just published in the journal Animals, the Ridden Horse Pain Ethogram (RHpE) was applied to horses competing last year at the Hickstead-Rotterdam Grand Prix Challenge and the British Dressage Grand Prix National Championship.
The results were compared to those from an earlier study, which assessed horses competing in World Cup Grand Prix qualifying competitions or finals.
Dyson led research about three years ago that led to the development of the RHpE, and is extensively trained in its use.
It comprises 24 behaviours, each with strict definitions, that occur more frequently in a horse with musculoskeletal discomfort compared with a non-lame horse.
They include the likes of mouth opening with separation of the teeth for at least 10 seconds, repeated head tilting, persistent tail swishing, an intense stare for five or more seconds, spooking, bucking, rearing, tail clamping, repeated tongue exposure, and putting the ears back for more than five seconds.
The presence of at least 8 of the 24 behaviours is considered a reliable indicator of the presence of an underlying musculoskeletal problem. The higher the tally, the greater the likelihood that the horse has musculoskeletal discomfort which may compromise performance.
It has previously been shown that the most frequent score in non-lame horses is 2 out of 24.
The most frequent RHpE score for 147 competitors at World Cup Grand Prix events from 2018 to 2020 was 3 out of 24, ranging from 0–7. This indicated that most of the horses were working comfortably.
In the latest study, Dyson applied the ethogram to 38 competitors at the Hickstead-Rotterdam Grand Prix Challenge and 26 competitors at the British Dressage Grand Prix National Championship, based on video recordings of the horses, all taken in a similar manner.
The most frequent RHpE scores were 4 for the Hickstead-Rotterdam event, ranging from 0 to 8; and 6 for the British Dressage Grand Prix National Championship, ranging from 1 to 9.
“These scores were significantly higher than the World Cup competitors,” Dyson and Pollard noted.
“This was associated with a higher prevalence of lameness and gait abnormalities in canter and more frequent errors in passage and piaffe, canter flying changes, canter pirouettes and rein back in the non-elite horses compared with the World Cup competitors.”
In both British events, actions such as ears back, an intense stare, repeated tail swishing, hindlimb toe dragging, having the tongue out, and crooked tail-carriage occurred more frequently.
The authors found a moderate negative correlation at the British Dressage Championships between the RHpE scores and the professional judges’ scores — that is, there was a moderate tendency for horses with higher RHpE scores to receive poorer scores from the judges. There were no professional judges for the Hickstead-Rotterdam Challenge, with scores allocated via remote audience participation.
Discussing their findings, Dyson and Pollard said they had expected the horses in the current study to have higher median RHpE scores than those in the World Cup competitions, despite 10 horses being included in both data sets.
“It seems likely,” they said, “that a proportion of the lower-level Grand Prix horses are experiencing musculoskeletal discomfort and with appropriate investigation and management both their welfare and performance could be enhanced.”
The authors noted that repeated tail swishing was observed in the majority of competitors, and is specifically mentioned in the FEI Dressage Rules as a “sign of nervousness, tension or resistance on the part of the Horse and must be taken into account by the Judges in their marks for every movement concerned, as well as in the collective mark”.
The pair noted that, as previously documented for elite Grand Prix competitors, there were rider or training errors in the current study that resulted in a potentially avoidable loss of marks for inaccuracies, for example, halts not being at the marker and an incorrect number of rein back steps.
Although a high frequency of carrying the head behind vertical — 10 degrees or more for 10 seconds or more in any movement — may be compounded by the presence of musculoskeletal discomfort, it seems likely that this may also be in part a reflection of modern-day training, they said.
“The observation of head behind vertical increased in frequency among elite Grand Prix horses between 1992 and 2008. It is clearly not being heavily penalised by judges.”
This head and neck posture may have adverse consequences for optimal muscle development, they said, and may have the potential to predispose horses to injury.
“The high frequency of gait abnormalities in trot and canter in the current study and the inability to perform correctly many of the movements requiring increased collection may reflect the consequences of inadequacies in basic training.”
Dyson and Pollard said the failure to recognise pain-related gait abnormalities has welfare implications and may jeopardise longevity of performance.
“Improvements in basic training, by establishing more correct movement patterns, could potentially reduce the risks of repetitive strain injuries.”
They said appropriate investigation and targeted management of horses with musculoskeletal discomfort may enhance both their performance and welfare.
Dyson, S.; Pollard, D. Application of the Ridden Horse Pain Ethogram to Horses Competing at the Hickstead-Rotterdam Grand Prix Challenge and the British Dressage Grand Prix National Championship 2020 and Comparison with World Cup Grand Prix Competitions. Animals 2021, 11, 1820. https://doi.org/10.3390/ani11061820