Getting to the Bottom of Poor Performance

Poor performance in the equine means a loss of performance or the inability of the horse to perform at previous levels or to the degree that might be expected. In a recent webinar with Dr Melanie Perrier, we discussed this presentation in our equines. 

The cause of poor performance is usually multiple concurrent conditions affecting any of the body systems, including respiratory, cardiovascular, neurological, musculoskeletal, or gastrointestinal. Diagnosis can be challenging, unrewarding and complicated, and may require the use of specialised tools and equipment.

With poor performance, a proper diagnosis is essential for the correct treatment and rehabilitation of the problem. Let us discuss some of the ways these patients may present, and what we can do about it.

What is poor performance?

‘Poor performance is a term that is quite widely used, but it is a very negative term and we should come up with a better way to describe these cases.’ Dr Melanie Perrier. 

The term can mean different things, depending on a variety of factors, including the discipline in which the horse participates. For example, poor performance for a racehorse is different from poor performance in a showing horse. A racehorse may fade too quickly or struggle to attain speed, while in the showing horse, poor performance may be linked to changes in gait, difficulties with transitions, and possibly even behavioural changes.

One of the challenges we have with the term ‘poor performance’ is that it is difficult to define and therefore measure. Without having outcome measures, how can we measure dysfunction or improvement?

Causes of poor performance

‘An accurate history, combined with thorough clinical examination of the whole horse, should permit the establishment of a list of problems requiring further investigation.’ S. Dyson, 2015. 

The many causes of poor performance usually occur concurrently rather than individually.

In a study of 348 horses, a definitive diagnosis could be reached for 73% of horses, and included (Martin et al., 2000):

Gastric ulceration was not listed in this study, but is another common cause of poor performance, as highlighted by Dr Melanie Perrier during her lecture. In a study evaluating a sample of horses with and without clinical signs of gastric ulceration, 52% of horses with no clinical signs had ulcerations present.

Performance horses are at a high risk of ulceration as a result of high grain-based diets, which lower the stomach pH and increase fermentative bacteria in the stomach, which produce organic acids that cause injury to the stomach mucosa (Andrews et al., 2005). Dietary changes, together with reducing stress and travel time, are important to prevent recurrence of ulcers in these horses.

In the Martin study above, lameness was present in only 15 of the horses, but in concurrent studies, lameness in working horses believed to be sound was as high as 65% (Dyson & Greve, 2016). This population of horses was considered to be sound; another way of putting it is that  the owners did not feel their horses suffered from poor performance. This raises the question again of how we define poor performance, and how we measure it.

Diagnosing poor performance

‘There is not a right and a wrong way of investigating musculoskeletal causes of poor performance in sports horses, and the methods of investigation are, in part, determined by the clinical signs.’ S. Dyson, 2015.

Dr Melanie Perrier suggests that we approach these cases with an open mind, and with access to specific equipment. With the prevalence of dynamic obstruction of the airways, the use of a high speed treadmill can be a key factor in the assessment of these horses, as can the use of scintigraphy (Morris & Seeherman, 1991).

The clinical assessment must be methodical, thorough and logical. The following table provides some guidance on aspects to test for: 

A thorough history-taking process is essential, as is gait assessment. Gait assessment should be repeated under saddle, and should include all activities that the rider experiences as challenges for the horse. Dr Melanie Perrier highlights the importance of diagnostic analgesia in this process, and shares the value added by this tool in multiple case examples. She also advises that when possible, objective measuring tools should be used for gait assessment, such as portable sensors.

Another aspect to consider during evaluation is the horse-saddle-rider interaction. Dr Anne Bondi joined us in a previous webinar to discuss this relationship, and I highly recommend rewatching that. When considering this relationship, it is important to assess saddle fit for both the rider and horse, the weight of the rider, rider symmetry, skill and style. A good rider can mask signs of subtle asymmetry in the horse, and all of this needs to be considered. (Dyson & Greve, 2015).

Treating poor performance

‘Lack of willingness to go forward freely, lack of power, shortened steps and stiffness of the cervical or thoracolumbosacral regions are common, non-specific signs of musculoskeletal causes of poor performance in sports horses.’ S. Dyson, 2015. 

The treatment of poor performance will depend on the diagnosis or diagnoses, and our role as Vetrehabbers will be to support the horse, owner and primary veterinarian through the rehabilitation process of various musculoskeletal pathologies. These will range from overriding dorsal spinous processes, to arthritis, navicular disease or sacroiliac dysfunction – to name but a few of the conditions we might see.  

Conclusion

Poor performance in the equine is a common problem experienced by our equine population, and can be used to describe changes in behaviour, movement and work ethic in working horses.

Causes of poor performance can come from any of the body systems, and therefore thorough veterinary examination is essential, and often requires specialised equipment.

Musculoskeletal causes of poor performance are still poorly defined and understood, but this is certainly our area of interest within the very broad area of poor performance.

It is important to consider that the causes of poor performance are often concurrent, and rarely appear alone.

Resources

1. Andrews, FM, Buchanan, BR, Elliot, SB, Clariday, NA, Edwards, LH. (2005). Gastric ulcers in horses. Journal of Animal Science, Vol 83 (13).
2. Down, S. (2008). Evaluating poor performance, https://www.vettimes.co.uk/app/uploads/wp-post-to-pdf-enhanced-cache/1/evaluating-poor-performance.pdf
3. Dyson, S. (2015). Evaluation of poor performance in competition horses: A musculoskeletal perspective. Part 1: Clinical assessment. https://doi.org/10.1111/eve.12426
4. Dyson, S, Greve, L. (2016). Subjective gait assessment of 57 sports horses in normal work: A comparison of the response to flexion tests, movement in hand, on the lunge, and ridden. Journal of Equine Veterinary Science, Vol 38.
5. Greve, L, Dyson, S. (2015). Saddle fit and management: An investigation of the association with equine thoracolumbar asymmetries, horse and rider health. Equine Veterinary Journal, Vol 47(4): 415-21.
6. Martin Jr, BB, Reef, VB, Parente, EJ, Sage, AD. (2000). Causes of poor performance of horses during training, racing, or showing: 348 cases. Journal of the American Veterinary Medical Association, Feb, Vol. 216(4): 554-8.
7. Morris E, Seeherman HJ. (1991). Clinical evaluation of poor performance in the racehorse: The results of 275 evaluations. Equine Veterinary Journal, May, Vol. 23(3):169-74.
8. Murray, MJ, Grodinsky, C, Anderson, CW, Radue, PF, Schmidt, GR. Gastric ulcers in horses: A comparison of endoscopic findings in horses with and without clinical signs. Equine Veterinary Journal, Vol. 21 (57).
9. Quiney, LE, Ireland, JL, Dyson, SJ. (2018). Evaluation of the diagnostic accuracy of skeletal scintigraphy in lame and poorly performing sports horses. Vet Radiol Ultrasound,  Jul, Vol. 59(4): 477-489.
10. Zimmerman, M, Dyson, S, Murray, R. (2011). Comparison of radiographic and scintigraphic findings of the spinous processes in the equine thoracolumbar region. Vet Radiol Ultrasound, Nov-Dec, Vol. 52(6): 661-71.
11. Zimmerman, M, Dyson, S, Murray, R. (2011). Impinging and overriding spinous processes in the thoracolumbar spine: The relationship between radiological and scintigraphic findings and clinical signs. https://doi.org/10.1111/j.2042-3306.2011.00373.x 

Visit our members’ portal to watch the following webinars:

1. Poor performance in the equine patient, with Melanie Perrier 
2. How tack influences movement, with Lauren Birckbeck 
3. The factors of evaluating an appropriate weight ratio for individual horse-rider combinations, with Anne Bondi 
4. Selected cases of ligament/tendon injury in horses, with Melanie Perrier 
5. Rehabilitation of horses affected with tenosynovitis 
6. Horse-saddle-rider interaction, with Anne Bondi