Scoping Advancements

by Kristen Manning

In the early 1990s that the scoping (post-sale endoscopic examination) of yearlings was first conducted and ever since then there has been debate as to how accurate the readings of the grading system have been.

The Lane-Bain Fallon 5-point grading system (grade 1, 2, 3, 4, 5) was introduced in 1993 and has been used extensively across Australia and New Zealand whilst the Havemeyer 7-point (1, 11 1, 11 2, 111 1, 111 2, 111 3, V) grading system, established in 2003, has been utilized in the northern hemisphere.

Extensive studies have been conducted across the world, including recent ones in Australia; leading to the local sales companies agreeing to ditch the old system and embrace the Havemeyer at all yearling sales kicking off with the 2025 Magic Millions.

The relationship between yearling laryngeal function and future performance is the motivator behind scoping; buyers seeking confidence in regards to long term soundness of their sometimes very expensive purchases.

Which is why buyers have taken the current readings into account, wary of the risks involved of buying a horse with a grade 3 or worse scope.

And to a certain extent this has worked well, Dr Josie Hardwick noting that “it has helped to weed out the very high risk yearlings.”

Dr Hardwick, along with Professor Ben Ahern and Professor Samantha Franklin as a University Of Adelaide team, has completed an Agrifutures funded two year study into the relationship between yearling sale readings and racing performance at the ages of two, three and four.

And what they have found is that there are too many variations for the 5-point grade system to be fully effective.

“Firstly we conducted a study to identify the main area of concern,” she said whilst noting that it was already known just what people were worried about - “a lack of clarity” in regards to the the grade assigned at the sales and how well a horse raced.

“Arguably the most clinically significant disease of the upper airway of horses” is how the study describes the affliction, one which “usually affects the left side of the larynx (voice box) and occurs most commonly in larger horses, such as thoroughbreds, warmbloods and draft breeds.”

“As the condition progresses, the nerve input to the laryngeal muscles is reduced, resulting in the muscles being unable to fully open the larynx Consequently, the horse breathes in air through a smaller than normal airway hole (akin to breathing through a straw) which causes it to make a roaring or whistling noise, particularly during fast work.”

“The disease impairs the ability of the horse to perform strenuous exercise, and has serious health consequences for the horse and economic implications for the owner.”

Whilst the scoping system in place has worked to a certain extent, the grade a horse receives is prone to variability from differing factors such who did the scope, what the conditions were like at the time, the mental and physical state of the horse, the time of day, the degree of fatigue, the degree of restraint (such as the use of a twitch) applied, etc.

The Havemeyer system, which allows for greater variation, has proven to be more consistent and the study suggests that veterinarians be trained to objectively interpret laryngeal function in order to further reduce the variability of their assessments.

The system is a “more granular” one and therefore a more useful one as it allows for horses with “intermediate” laryngeal function to be split into “two distinct groups with different future performance outcomes.”

Approximately 4% of the sale population were classified as intermediate.

Overall what they found was that for most horses sold at sales, laryngeal function did not impact future race performance though a subset of horses - that 4% - who performed poorer at four was identified.

It was also discerned that the grading system could be further refined with the outcomes of horses allocated a grade of II 2 did not have different performance outcomes from those with grade I or II 1.

In the past such horses would have received a grade 3 reading, one which effected buyer confidence Despite there being on real evidence that they are more or less likely to develop wind problems.

“It was a pass or fail” attitude that Dr Hardwick would like to see us get away from, “there is more to risk assessment than that.”

An equine surgeon who has worked in the thoroughbred industry for 16 years, Dr Hardwick has seen the issue “from all sides,” from diagnosis to the racetrack to the operating theatre.

“It has always been of special interest to me,” she said, delighted when funding was secured for this study.

One which has recommended that there should be continued development in the system and better communication to industry stakeholders as well as the use of the 7-point scale over the 5-point one; which each Australian sales company has now agreed to.

It was also recommended that a panel of three experts study the pre-sale scopes in order to provide consensus of the grades.

Over 5000 endoscopic recordings from Australian yearling sales conducted in 2018 and 2019 were studied for this investigation; reviewed by a team of experienced veterinarians They looked at both point scales and at performance data.

There was no difference in race performance between 95% of the horses examined though those with grade 111 1 function earned less as four-year-olds with fewer career wins and placings.

Dr Samantha Franklin was pleased to involve industry participants in the process, a series of round stable interviews with focus groups of buyers, breeders and sale day veterinarians leading to robust discussion.

“No other studies have asked thoroughbred stake holders to share their views and concerns about the yearling sales endoscopy process,” she said.

“By bringing together a cross-section of stakeholders ho are impacted by this issue from all angles, we gained a deeper understanding of not only what they think, but how they think and why, and we could explore their views on how the process might be improved.”

“The yearling endoscopy process should enhance buyer confidence and remove ambiguity.”

Some stakeholders were wary about what they saw as a more complicated system but the researchers are confident that education and experience will lead to greater confidence.

“This grading scale could be further simplified when communicating levels of risk to stakeholders,” Professor Franklin said The research does not end here, Dr Hardwick saying that she is “very excited” about the next study looking at the earnings and performance of horses post treatment; i e tie-back surgery.

“We will have data in the next six months,” she said, noting that other fields of research are being taken overseas, such as in Europe where electrical stimulation of the nerve is being studied in order to train and strengthen the muscles.

Meanwhile she sees the break down of grade 3 into two distinct groups with different risk factors an important one whilst also noting that there are “different degrees of roarers.”

“Some have complete collapse of the laryngeal nerve, others have partial and seem to cope quite well with it It is a complex diseases with multiple causes.”

Which means that every bit of research conducted into the field is worthy and the new system of grading at the sales is a definite step in the right direction.