Latest Headshaking Research Presented at British Equine Veterinary Association (BEVA) Congress 2023 in Birmingham, UK
Last week Dr Veronica Roberts presented our group’s latest research on horses with TRIGEMINAL-MEDIATED HEADSHAKING at the 2023 BEVA CONGRESS in Birmingham.
Headshaking is a distressing condition for both affected horses or ponies and their owners. It’s often discussed as being similar to neuralgia in people. Neuralgia is pain from nerves, and human patients often describe it as being similar to “burning”, “electric shock” or “pins and needles”. In horses, the pain causes violent, usually vertical (up and down) movements of the head, as shown in the video. Please note that the video has been slowed down to make it easier to see the signal and the head movement together.
The project started in 2021 with a grant from the Langford Trust for Animal Health and Welfare. Equine clinicians and equine internal medicine specialists Dr Veroncia Roberts (University of Bristol) and Dr Kirstie Pickles (Nottingham Veterinary School), epidemiologist Dr Jane Williams (Hartpury University) and myself wanted to find a more objective way to assess the severity and frequency of head shaking. The aims were to:
- Aid diagnosis of headshaking
- Help further understanding of the causes and triggers of headshaking
- Develop a technique to monitor horses over longer periods to assess response to treatment
The technique we have developed is based on a self-contained poll-mounted tri-axial accelerometer and data-logger, which weighs only 20g and which can record for up to 14 days. We recorded the head movements of normal-healthy horses, lame horses and horses with headshaking due to a known cause (e.g. dental disease) and horses with trigeminal-mediated headshaking during 5 minutes of lunging.
Examples of recordings of head motion at trot on the lunge from a healthy-sound horse (GREEN), a low-grade lame horse (YELLOW) and a headshaker (BLUE) are shown below. It’s pretty easy to pick out the violent head movements on the recording from the headshaker marked by the BLUE ARROWS, which are not present on the control or lame horse recordings. The healthy-sound horse (GREEN) has a very regular head movement pattern as we would expect. There are two head movements that are larger than the rest for the lame horse (YELLOW ARROWS) but these are smaller and lower/slower speed (lower frequency) than the headshakes marked by the BLUE ARROWS. These are both violent (the g force is much higher) and they happen very quickly (the line is almost straight up and down).
The type and frequency of head movements were found to be significantly different between the true trigeminal-mediated headshaking horses and all other horses, including the headshakers due to a known cause (i.e. not true idiopathic headshakers where the cause is not known).
As a result, for the first time we have an objective way to measure headshaking in horses and ponies, which we will now look to develop and apply to help improve diagnosis and understanding of this horrible condition.
If you would like to learn more about equine trigeminal-mediated headshaking we have a range of resources from Dr Kirstie Pickles, who along with Dr Veronica Roberts, is an internationally recognised veterinary specialist on equine headshaking. See links below.
Links to further information about head-shaking:
- Article – Headshaking, Head Flicking, Head Tossing, Trigeminal Mediated Headshaking
- Webinar – Headshaking – Dr Kirstie Pickles
- Webinar – Headshaking Q&A – Kirstie Pickles
- Poll – Headshaking – bridle poll results
