Demography and disorders of English Cocker Spaniels under primary veterinary care in the UK

**Background:** The English Cocker Spaniel (ECS) is a popular family dog in the UK, but limited data exist on its health in the general population. This study aimed to describe demography, morbidity, and mortality in ECS under primary veterinary care in the UK during 2016 using VetCompass™ data. The authors hypothesized that aggression prevalence is higher in males than females and higher in solid-coloured than bi-coloured ECS.

**Methods:** The study included 10,313 ECS (3.06% of 336,865 dogs) from 438 UK clinics. A cross-sectional analysis of cohort clinical data was used to estimate one-year period prevalence. Electronic patient records (EPRs) from a random sample of 2,318 ECS (22.48%) were manually reviewed to extract diagnoses, which were mapped to fine-level and group-level precision terms. Mortality data were also extracted. Statistical analyses included two-proportion z-tests, chi-square tests, and Mann–Whitney U tests, with significance set at P<0.05.

**Key Results:** The median age was 4.57 years (IQR 2.25–8.01), and median adult bodyweight was 15.05 kg (IQR 13.12–17.35). Annual proportional birth rates were stable (2.97–3.51%) from 2005–2016. The most common fine-level disorders were periodontal disease (n=486, 20.97%, 95% CI: 19.31–22.62), otitis externa (n=234, 10.09%, 95% CI: 8.87–11.32), obesity (n=229, 9.88%, 95% CI: 8.66–11.09), anal sac impaction (n=187, 8.07%, 95% CI: 6.96–9.18), diarrhoea (n=113, 4.87%, 95% CI: 4.00–5.75), and aggression (n=93, 4.01%, 95% CI: 3.21–4.81). Aggression prevalence was higher in males (4.95%) than females (2.87%) (P=0.015) and in solid-coloured (7.00%) than bi-coloured dogs (3.66%) (P=0.010). Among solid colours, golden-coated dogs had the highest aggression prevalence (12.08%). The median age at death was 11.44 years (IQR 9.46–13.47), with females living longer (12.01 years) than males (11.00 years) (P=0.052). The most common grouped causes of death were neoplasia (n=10, 9.26%, 95% CI: 3.79–14.73), mass-associated disorders (n=9, 8.33%, 95% CI: 4.45–15.08), and collapse (n=8, 7.41%, 95% CI: 3.80–13.94).

**Clinical Implications:** The high prevalence of periodontal disease (20.97%) underscores the need for routine oral examinations and preventive dental care in ECS, especially in older dogs. Otitis externa (10.09%) and obesity (9.88%) are also common, with obesity peaking in middle-aged dogs; veterinarians should routinely assess body condition score. The elevated aggression prevalence, particularly in solid-coloured males (especially golden), suggests that prospective owners concerned about aggression may consider female or bi-coloured dogs. Neoplasia and mass-associated disorders are the leading causes of death, highlighting the importance of cancer surveillance. These findings support evidence-based breed health advice and identify priorities for improving ECS welfare.