Dental disease is frequently only identified during routine dental assessments or in the presence of obvious, external clinical signs, such as facial swellings or nasal discharge (Dixon et al., 1999; Taylor & Dixon, 2007).

More subtle changes in eating behaviour, such as prolonged eating times and preferences for soft feeds, have been shown to occur in animals with dental disease (Fleming & Burn, 2014; Watanabe et al., 2020; Watanabe et al., 2019). Similar changes in both eating and general behaviour have been reported in horses with dental disease, although the retrospective nature of these studies and their reliance on owner feedback are liable to pitfalls such as recall bias and subjectivity (Rainbow, 2023; Pehkonen et al., 2019; Laukkanen et al., 2023; Hipp et al., 2020). Recognition of these behavioural indicators of oral pain is of increased importance in a species where direct examination of dentition or the provision of prophylactic dental care is neither feasible nor safe for owners (Enlund et al., 2020; Buckley et al., 2011).

Clinical signs associated with dental disease based on a review of the existing literature and combined with parameters included in pain scales validated in horses with head-related pain to formulate a composite equine oral and maxillofacial pain scale (ECOMPS), as has been achieved in other species (Della Rocca et al., 2019). Content (face) validity was subsequently established based on the opinion of experts in the target field – in this case, veterinarians board-certified in equine dentistry and behaviour who were not involved in the study design or questionnaire development.

Preliminary validation of this novel pain scale was subsequently undertaken. This aimed to determine whether the equine composite oral and maxillofacial pain scale (ECOMPS) could differentiate between horses with and without dental disease and determine the inter-observer reliability of the ECOMPS. Inclusion criteria were horses with dental pathology diagnosed by a specialist or resident in equine dentistry and with no other known comorbidities based on clinical history. A further group of horses who have undergone a sedated oral examination (including oroscopy) with no dental pathology identified nor any history of other potentially painful conditions were included as a control. Exclusion criteria were horses who had received analgesics within 10 days prior to the study or any horses not accustomed to being stabled or those with stereotypies. Horses were observed for 10 minutes and scored using the ECOMPS at the end of this observation period. Scores were compared between groups and between observers to assess the scale’s ability to differentiate between horses with- and without pain and to evaluate inter-observer reliability.

References
- Buckley, C., Colyer, A., Skryzywanek, M., Jodkowska, K., Kurski, G., Gawor, J., Ceregrzyn, M. (2011) ‘The impact of home-prepared diets and home oral hygiene on oral health in cats and dogs, Br. J., Nutr, 106, S124-S127
 - Della Rocca, G. et al. (2019) ‘Development, Preliminary Validation, and Refinement of the Composite Oral and Maxillofacial Pain Scale-Canine/Feline (COPS-C/F)’, Frontiers in Veterinary Science, 6, p. 274. Available at: https://doi.org/10.3389/fvets.2019.00274.
- Dixon, P. M., Tremaine, W. H., Pickles, C., Kuhns, L., Hawe, C., McCann, J., McGorum, B., Railton, D. I., Brammer, S. (1999) ‘Equine dental disease Part 2: A long-term study of 400 cases: disorders of development and eruption at variations in position of the cheek teeth’ Equine Veterinary Journal, 31 (5) pp. 369-377
- Enlund, K. B., Brunius, C., Hanson, J., Hagman, R., Hoglund, O. V., Gustas, P., Pettersson, A. (2020) ‘Dog Owners’ Perspectives on Canine Dental Health – A Questionnaire Study in Sweden’ Frontiers in Veterinary Science, 7, 298.
- Fleming, M. and Burn, C. C. (2014) ‘Behavioural assessment of denta pain in captive Malayan sun bears (Helarctos melayanus)’ Animal Welfare, 23, pp. 131-140
- Hipp, L., Bünning, M., Munnes, S., Sauermann, A. (2020) ‘Problems and pitfalls of retrospective survey questions in COVID-19 studies’ Survey Research Methods, 14 (2), pp. 109-114
 - Laukkanen, T., Karma, L., Virtala, A. – M., Mykkänen, A., Pehknonen, J., Rossi, H., Tuomola, K., Raekallio, M. (2023) ‘Behavioral Signs Associated With Equine Cheek Tooth Findings’ Journal of Equine Veterinary Science, 121, 104198
 - Pehkonen, J., Karma, L., Raekallio, M. (2019) ‘Behavioral Signs Associated With Equine Periapical Infection in Cheek Teeth’ Journal of Equine Veterinary Science, 77, pp. 144-150
 - Rainbow, W. (2023) ‘Behavioural and physical changes in equine patients after complete extraction of all incisors due to equine odontoclastic tooth resorption with hypercementosis’ Equine Veterinary Education, 00, 1-5. Available from: https://doi.org.10.1111/eve.13892
- Watanabe, R. et al. (2019) ‘A multidisciplinary study of pain in cats undergoing dental extractions: A prospective, blinded, clinical trial’, PLOS ONE. Edited by F. Staffieri, 14(3), p. e0213195. Available at: https://doi.org/10.1371/journal.pone.0213195.
- Watanabe, R., Frank, D., Steagall, P. V. (2020) ‘Pain behaviors before and after treatment of oral disease in cats using video assessment: a prospective, blinded, randomized clinical trial’ BMV Veterinary Research, 16: 100