Diagnosed causes of sinonasal disease in horses

Diagnosed causes of sinonasal disease in 1600 horses and associations with clinical signs, computed tomographic findings and case outcome

Equine Vet J. 2026 Sep 8. doi: 10.1002/evj.70308. Online ahead of print.
Authors
Padraic Dixon 1 , Tim Barnett 2 , Eric Parente 3 , Rhiannon Morgan 4 , John Mark O’Leary 5 , Lieven Vlaminck 6 , Alison Talbot 7 , Alexandra Gillen 7 , Tom McGinley 8 , Moses Brennan 9 , Henry Tremaine 10 , Elke Polaris 11 , Erica Dobbs 12 , Ben Anghileri 13 , Linda Wright 14 , Elin Olsson 15 , Jonathan Olijnyk 16 , Charles Alexandre 17 , Neil Townsend 18 , Adam Northwood 19 , Tim Mair 20 , Jane Haden 21 , Richard J M Reardon 22
Affiliations

1 Independent Veterinary Consultant, Edinburgh, UK.
2 Rossdales Equine Hospital, Newmarket, UK.
3 University of Pennsylvania, New Bolton Center, Kennett Square, Pennsylvania, USA.
4 IVC/Evidensia, Keynsham, Bristol, UK.
5 University College Dublin, Dublin, Ireland.
6 University of Ghent, Ghent, Belgium.
7 University of Liverpool Equine Hospital, Neston, UK.
8 Liphook Equine Hospital, Hampshire, UK.
9 Rainbow Equine Hospital, Malton, Yorkshire, UK.
10 B&W Equine Hospital, Gloucestershire, UK.
11 Morette Clinic, Asse, Belgium.
12 Rood and Riddle Equine Hospital, Lexington, Kentucky, USA.
13 Oakham Veterinary Hospital, Leicestershire, UK.
14 IVC Evidensia, Helsingborg, Sweden.
15 IVC Evidensia, Strömsholm, Sweden.
16 Swedish University of Agricultural Sciences, Uppsala, Sweden.
17 University of Liege, Liège, Belgium.
18 Three Counties Equine Hospital, Worcestershire, UK.
19 Royal Veterinary College, London, UK.
20 Bell Equine Veterinary Clinic, Maidstone, Kent, UK.
21 Equine Dental Clinic, Wimborne, UK.
22 University of Edinburgh, Edinburgh, UK.

PMID: 42708900
DOI: 10.1002/evj.70308

Abstract

Background: The diagnosis of equine sinonasal disorders has been greatly enhanced by using computed tomographic (CT) imaging.

Objectives: To explore associations between specific diagnoses and clinical and CT findings and between specific diagnoses and case outcome in equine sinonasal disease.

Study design: Retrospective case series.

Methods: Data were collected from medical records from 19 equine hospitals on cases of sinonasal disease, all of which underwent CT imaging. Case outcome was obtained from clinical records, and/or by contacting clients and referring veterinarians. Logistic regression analysis was used to examine associations between specific diagnoses and clinical and CT variables and examine associations between specific diagnoses and case outcome.

Results: Dental sinusitis due to apical infection was the most common cause of sinusitis (n = 693; 43.3% of cases). Other causes were primary sinusitis (n = 329; 20.6%), sinus cyst (n = 178; 11.1%), progressive ethmoid haematoma (PEH) (n = 100; 6.3%), traumatic sinonasal disease (n = 90; 5.6%), sinonasal neoplasia or suspect neoplasia (n = 86; 5.4%), other non-neoplastic sinonasal growths (n = 11; 0.6%), mycotic infection (n = 65; 4.1%), sinus pneumocele (n = 5; 0.3%), oro-nasal fistulae-related sinusitis (n = 4; 0.25%), sinus mucocele (n = 2; 0.13%) and facial suture infection (n = 1; 0.06%) cases. Facial swelling was more common with sinonasal cysts, tumours, trauma and mycosis than other diagnoses. Nasal malodour was most common with dental sinusitis. Nasal airflow obstruction was most common with sinonasal cysts, PEH and tumours. Empyema of the nasal conchal bullae was least common with sinus cysts, PEH, trauma and tumours (less purulent types of sinusitis). More severe grades of hyperostosis were associated with sinus cysts and tumours. Sinonasal tumours (odds ratio [OR] 0.03, 95% confidence interval [CI] 0.01-0.07) and PEH (OR 0.23, 95% CI 0.12-0.43) had a significantly lower likelihood of cure than primary sinusitis.

Main limitations: This was a retrospective study, and histology was not performed in some cases.

Conclusions: Equine sinonasal disease has a range of underlying causes which impacts the clinical presentation and outcome.

Keywords: computed tomography; dental disease; horse; sinonasal disease aetiology; sinus disease.

© 2026 EVJ Ltd.

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