One of the more frustrating clinical syndromes to manage for equine veterinarians and horse owners is headshaking. While the symptomatology of equine headshaking syndrome (EHS) is well understood, it is often difficult to determine the exact cause of this spontaneous disorder. Of various remedies tried, some work and many don’t.
German horse owner assessment of attempts at resolution sheds some light on possible therapeutic options [Stange, L.M.; Krieter, J.; Czycholl, I. Overview of the Current Situation in a Sample of Headshakers and Owner Assessment of Effective Therapeutic Measures Used in Germany. Journal of Equine Veterinary Science 2020, vol 95; doi.org/10.1016/j.jevs.2020.103270].
The survey was answered by 163 horse owner respondents with headshaking horses—64.4% geldings, 33.7% mares, and 1.8% stallions—ages ranging from 5-34 years. Nearly half of the horses were younger than age 10; previous literature reported that more than 80% of EHS-affected are less than age 10. The average horse age in this study was reported at 12.7 years. Over half of the horses were affected with co-morbidities besides headshaking syndrome: musculoskeletal (17.8%), gastrointestinal (7.6%), respiratory (7.6%), eyes (6.5%) or teeth and skin (13.5%). Stereotypical behavior occurred in 18.4% of those affected by headshaking.
Survey information of suspected cause noted by owner is interesting:
- A specific event triggered EHS onset in 28.2%.
- Stress was considered the cause in 18.4%—examples include training and competition, training of young horses, and ill-fitting saddles.
- Vaccination, especially against herpesvirus, was considered the inciting trigger in 2.5%.
- Kissing spine or skull fracture and other various diseases was thought to be the inciting cause in 5.5%.
Symptoms were described as vertical head movement in 75.5%, horizontal head movement in 21.5%, and 63.1% rubbed nose on foreleg, objects,or ground while moving. Nearly half displayed snorting or sneezing. A third did a forehand strike. While EHS tends to be more common in moving horses, 27% at rest showed signs. Just over half showed headshaking at lunge and 83.4% when ridden under saddle. A notable percentage (44.8%) were difficult to ride or not able to be ridden due to associated dangerous behavior like the forehand strike.
Nearly 91% of horse owners attempted therapies, with 11% using medical or surgical treatment:
- 54% used a nose cover.
- 9.8% used anti-inflammatory medications.
- 1.2% elected surgical intervention.
- 6.7% tried food supplements.
- 22.7% tried saddle or bridle (bit-less) modifications.
- 31.9% tried osteopathy or physiotherapy.
- 29.4% changed their riding style to a “biomechanically correct” riding style.
In general, 70.6% of EHS horses showed improvement by owners trying one strategy or a combination of these different therapies. None of the respondents reported using ultraviolet light-blocking face masks, which have been shown to provide good results. The authors note, “Reduced stress, suitable equipment, and a gentler influence of the reader lead to an improvement of symptoms.”