What’s New in Lameness Diagnosis - 2020 Conference - Part 10

Hello and welcome back to my blog about the Horses Inside Out conference 2020 - Anatomy In Action.

Today I would like to share with you the presentation by vet Sue Dyson on the second day of the conference.

Sue called this presentation ‘What’s is new in lameness diagnosis’

Sue is a world renowned vet and speaker you can find out more about Sue in my previous blog, as we were fortunate enough to have 2 presentations from her over the weekend.

In this presentation Sue discussed 3 recent studies, all of which she was a part of.

Here I would like to share with you some of the findings from these studies and my own notes from Sue’s presentation of these, I hope you find them useful!

Firstly Sue shared with us how one study has shown that Skeletal Scintigraphy (bone scanning) has extreme limitations, with there being an unacceptably high proportion of false negative and false positive results to make it a reliable diagnostic tool. (I did touch on this in my previous blog).

One of the notes I took from this part of the presentation was:

• Sidebone is likely to cause future lameness as there is a link between sidebone and future bony changes in the long pastern which can cause limb pain and lameness

Sue also discussed with us the value of ‘pattern recognition’ in linking clinical features of lameness. This recent study by Sue herself, used this to describe horses with otherwise unexplained forelimb lameness, which seems may have been attributable to cervical nerve root compression (in the neck).

Sue shared with us the following points reference horses with unexplained forelimb lameness:

1. Some horses displayed idiopathic hopping-type forelimb lameness

2. 24% tilted their nose away from the lame limb

3. 28% showed a change in the degree of lameness when ridden in contact compared to on a loose rein

4. It was a 50/50 split on whether horses appeared more or less lame when ridden in contact compared to on a loose rein

5. Lameness appeared to be linked to head and neck position

She believed that in these horses nerve route compression could be possible at C7-T1 (where the Cervial or neck part of the spine meets the Thoracic part of the spine, where the withers are)

To prove this theory Sue used nerve blocks, starting at the foot and working her way up the leg.

If the lameness was to get worse as the nerveblocks were applied further up the leg this showed that the lameness was most likely in fact coming from the neck.

This was fascinating to me, as usually when you see a horse with forelimb lameness you would automatically look to the foot or lower leg in the first instance, the neck would not necessarily be an area you would think to explore.

The third study also using ‘pattern recognition’ investigated the occurrence of, and risk factors for, concurrent suspensory ligament injuries in horses with hindlimb proximal suspensory desmopathy (PSD) also known as High Suspensory Disease.

For those of you not familiar with this term, PSD is a common injury in both the forelimbs and the hindlimbs of athletic horses and may occur in one limb or in both the forelimbs or both the hindlimbs at the same time.

I am going to break down the findings of this study into simplified points, they are:

• Horses up to 5 years of age with PSD in the hind limbs had a significantly higher risk of getting another suspensory injury than horses over the age of 6

• A high proportion of these horses less than 5 years old were in light work or had done no work. This suggests they were genetically predisposed to the injury

• High body weight to height ratio (which correlates to body condition score) was a risk factor for concurrent suspensory ligament injuries. Suggesting obesity is a risk factor

• The incidence of of hindlimb PSD appears to be increasing. Not only in upper level sport horses but also in general purpose horses - this is probably a multifactorial issue involving management practices, work conditions and arena surfaces

• The significant factors to consider in reference to suspensory ligament injuries are:

1. Age

2. Weight

3. Breed

4. Obesity - due to weight and metabolic factors

Body condition scoring is REALLY important!

Some further notes I took her were:

• For every 1 degree of angle in the hind limb (this is the tarsal or hock angle) there is 11% more chance of the horse developing PSD

• A horse with over a 165 degree angle or a straighter leg/angle is more likely to get suspensory issues

• Warmbloods have an increased risk compared to other breeds

• If the hock angle is 165 degrees of more Sue would not recommend purchasing the horse

Definitely some key points there that I shall be keeping in the back on my mind when assessing a treating horses.

I hope you have enjoyed this blog, I will certainly be looking out for further presentations from Sue that I may be able to attend, she is a fabulous speaker and fascinating lady.

Thank you again to Horses Inside Out for allowing me access to their professional images. Some of the images included are my own photos of Sue’s slides.

Thank you for visiting my blog, I look forward to sharing the next installment with you soon which will be about the presentation from Richard Hepburn about ‘Tuning the Equine Engine to Prevent Poor Performance’

Thanks again,

Jess | Jessica Limpkin Equine Massage Therapy

Study references:

1. Quiney, L., Ireland, J., Dyson, S. Evaluation of the diagnostic accuracy of skeletal scintigraphy in lame and poorly performing sport horses. Vet. Radiol. Ultrasound 2018, 59:477-489

2. Dyson, S. Unexplained forelimb lameness possibly associated with cervical radiculopathy. Equine vet. Educ. 2018, doi:10.1111/eve.12980

3. Gruyaert, M., Pollard, D., Dyson, S. An investigation into the occurrence of, and risk factors for, concurrent suspensory ligament injuries in horses with hindlimb proximal suspensory desmopathy. Equine vet. Educ. 2019, doi:10.1111/eve.13187