Summary: Reason for performing study: Headshaking in horses has been reported to be most commonly due to idiopathic neuropathic facial pain (trigeminal‐mediated headshaking). The prevalence of headshaking in horses in the UK is unknown. Objectives: To estimate owner‐reported prevalence of headshaking in horses in the UK and to report their case background and disease characteristics, as reported by owners. Study design: Cross‐sectional web based owner questionnaire. Methods: The questionnaire was advertised online via social media, horse forums, veterinary websites and equestrian magazines from 17th June 2016, until >1000 responses had been obtained. All UK horse owners were eligible to complete the questionnaire, however only one questionnaire could be completed per owner. Results: The estimated prevalence of owner‐reported headshaking in the sample population of horses (n = 1014), within the last year, was 4.6% (95% confidence interval 3.5–6.1), whereas 6.2% (95% confidence interval 4.9–7.9) of horses were reported by their owners to have shown signs of headshaking at any time‐point since ownership. There was no association of sex or breed. Nineteen percent of headshaking horses were reported to show headshaking at rest. Fewer than one‐third (30.2%, n = 19) of headshaking horses had been examined by a veterinarian for headshaking. Of horses seen by a veterinarian, the cause for headshaking remained unknown in the majority of cases (57.9% responses) and trigeminal‐mediated headshaking was reported as a diagnosis in just one case. Main limitations: The accuracy in data reporting by horse owners was not verified in this study. There may be a potential for bias towards over‐reporting due to the nature of survey participation. Conclusions: Within this sample, owner‐reported prevalence of signs of headshaking within the last year, in horses in the UK was 4.6%. Over two‐thirds of owners of headshaking horses did not seek veterinary intervention for headshaking. Trigeminal‐mediated headshaking was rarely reported by owners as a diagnosis.

Pain assessment is very important for monitoring welfare and quality of life in horses. To date, no studies have described pain scales for objective assessment of pain in foals. Studies in other species have shown that facial expression can be used in neonatal animals for objective assessment of acute pain. The aim of the current study was to adapt a facial expression-based pain scale for assessment of acute pain in mature horses for valid pain assessment in foals. The scale was applied to fifty-nine foals (20 patients and 39 healthy controls); animals were assessed from video recordings (30–60 s) by 3 observers, who were blinded for the condition of the animals. Patients were diagnosed with acute health problems by means of clinical examination and additional diagnostic procedures. EQUUS-FAP FOAL (Equine Utrecht University Scale for Facial Assessment of Pain in Foals) showed good inter- and intra-observer reliability (Cronbach’s alpha = 0.95 and 0.98, p < 0.001). Patients had significantly higher pain scores compared to controls (p < 0.001) and the pain scores decreased after treatment with NSAIDs (meloxicam or flunixin meglumine IV) (p < 0.05). Our results indicate that a facial expression-based pain scale could be useful for the assessment of acute pain in foals. Further studies are needed to validate this pain scale.