Demography, common disorders and mortality of Shih Tzu dogs under primary veterinary care in the UK.

Background: Shih Tzus are a popular dog breed in the UK although there is relatively little reported information on their health. This study aimed to characterise the demography, common disorders and mortality of Shih Tzus under primary veterinary care during 2016 in the UK using de-identified clinical records from the VetCompass™ Programme.

Results: The study population of 336,865 dogs under veterinary care during 2016 included 11,082 Shih Tzus (3.3%). The median age was 4.1 years (IQR: 2.1-7.1, range: 0.3-20.4) and mean adult bodyweight was 7.9 kg (SD: 1.9 kg). Annual proportional births increased from 2.2% of all dog births in 2005 to 3.8% in 2013, dropping to 3.3% by 2016. From a random subset of 2,423 Shih Tzus that had information extracted on disorders diagnosed during 2016, the most prevalent fine-level precision disorders were periodontal disease (n = 229, prevalence 9.5%, 95% CI: 8.4-10.7), anal sac impaction (180, 7.4%, 95% CI: 6.5-8.5) and ear disorders (134, 5.5%, 95% CI: 4.7-6.5). The most prevalent grouped-level precision disorders were cutaneous (n = 402, prevalence: 16.6%, 95% CI: 15.2-18.1), dental (322, 13.3%, 95% CI: 12.0-14.7), and ophthalmological (289, 11.9%, 95% CI: 10.7-13.3). Males were more likely than females to be diagnosed with skin disorders (P = 0.007) and musculoskeletal disorders (P = 0.010) while females were more likely than males to be diagnosed with hernias (P = 0.005). The median age of death was 12.7 years (IQR 8.7-14.3, range 2.0-19.9) and did not differ statistically between males and females. The most common grouped causes of death were enteropathy (7.9%, 95% CI: 3.9-15.4), heart disease (7.9%, 95% CI: 3.9-15.4) and poor quality of life (7.9%, 95% CI: 3.9-15.4).

Conclusions: Periodontal disease, anal sac impaction and ear disorders were identified as common health issues. Shih Tzus had higher prevalence of anal sac impaction, umbilical hernias and eye problems than reported previously in dogs overall, suggesting potential predispositions. Shih Tzus appear to be relatively long-lived compared to previous reports of lifespan in dogs overall. The results can inform veterinarians and owners on priority disorders for monitoring to protect welfare. Oral hygiene was highlighted as a healthcare priority.