Clinical and Genetic Findings in 28 American Cocker Spaniels with Aural Ceruminous Gland Hyperplasia and Ectasia

American Cocker Spaniels (ACSs) develop aural ceruminous gland hyperplasia and ectasia more often than dogs of other breeds. Data on the cause development these breed characteristic histopathological changes are lacking. We performed video-otoscopic examinations dermatological work-up 28 ACSs, obtained biopsies from each dog assessed statistical associations between presence disease history, clinical or microbiological findings underlying otitis externa (OE). Histological lesions were observed in 6/13 clinically healthy ears 13/15 with OE 19/28 examined dogs. Nine had histologically normal glands (odds ratio [OR] 6.2, 95% confidence interval [CI] 1.1-36.6). Bacterial growth culture exudate (OR 14.1, CI 2.1-95.3) was associated glandular changes, whereas previous history OE, cutaneous allergies not. Pedigree analysis a genome-wide association study (GWAS) 18 affected eight unaffected based diagnosis. While GWAS indicated tentative, but not statistically significant, chromosome 31, larger cohort is needed to confirm this preliminary result. Based our results, may also precede signs ACSs genetic aetiological component likely Further studies cohorts warranted verify results.