Computed tomographic findings in 1600 cases of equine sinonasal disease and associations with case outcome.

BACKGROUND

No study has described the computed tomographic (CT) sinonasal findings in a large cohort of referred sinonasal disease cases.

OBJECTIVES

To report the CT imaging findings in equine sinonasal disease and examine associations between case outcome and CT findings.

STUDY

DESIGN

Retrospective case series.

METHODS

Data were collected from medical records from 19 equine hospitals on sinonasal disease cases which had undergone CT imaging. Case outcome was obtained from clinical records, and/or by contacting clients and referring veterinarians. Multivariable logistic regression analysis was used to examine variables at presentation associated with case outcome.

RESULTS

The 1600 cases of sinonasal disease had unilateral sinusitis in 1457 and bilateral sinus disease in 143. The rostral maxillary sinuses (86.1% affected) and ventral conchal sinuses (74.8% affected) were most commonly involved. Fluid attenuation or distortion of the ventral nasal conchal bullae (NCB) was present in 21.3% and 39.3% of cases, respectively, and of the dorsal NCB, in 16.5% and 28.4% of cases, respectively. Hyperostosis (inflammatory thickening) of sinus-related bones was mild in 35.5%, moderate in 19.8%, severe in 8.7%, and absent in 36.1% of cases. A total of 659 non-fractured and 200 fractured apically infected teeth were found. The normal contralateral sinuses in 100 horses showed CT evidence of endodontic/apical infection in 114 cheek teeth. The multivariable model was built with data from 674 cases. Cases with apically infected non-fractured (odds ratio [OR] 2.15, 95% confidence interval [CI] 1.41-3.29) or fractured teeth (OR 2.03, 95% CI 1.08-3.81) (i.e., dental sinusitis) had a higher likelihood of cure than those that did not. Cases with caudal group sinusitis (OR 0.48, 95% CI 0.29-0.80) or moderate or severe bone hyperostosis (OR 0.53, 95% CI 0.36-0.78) had a lower likelihood of cure than those without.

MAIN LIMITATIONS: Retrospective study with incomplete data available for some cases.

CONCLUSIONS

Maxillary cheek teeth endodontic/apical infection does not always cause sinusitis. Sinus bone hyperostosis and caudal group sinusitis are associated with a lower likelihood of cure, whereas apical infections are associated with a higher likelihood of cure.