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

Canine Med Genet. 2024 Jan 24;11(1):2. doi: 10.1186/s40575-023-00135-y.

Abstract

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.

Keywords: Breed; Dog; EPR; Electronic patient record; Epidemiology; Pedigree; Primary-care; Purebred; Shih Tzu; VetCompass; Veterinary.

Plain language summary

The Shih Tzu is a popular small breed of dog in the UK. However, there is little information on common health conditions affecting this breed. This study aimed to describe the demography, common disorders, and causes of death of Shih Tzus in the UK in 2016 using the VetCompass™ Programme, which holds a database of anonymized clinical records of dogs attending primary-care veterinary practices in the UK.The study included 11,082 Shih Tzus (3.3%) from 336,865 dogs under veterinary care in the UK in VetCompass™ in 2016. The popularity of the Shih Tzu increased slightly from 2005 to 2013 but showed signs of decline towards 2016. The average age of Shih Tzus in the study was 4.1 years and the average adult bodyweight was 7.9 kg. The most common disorders affecting Shih Tzus in the study were periodontal disease (inflammation of the gums and tissue around the teeth, affecting 9.5% of Shih Tzus), anal sac impaction (7.4%) and ear disorders (5.5%). Male Shih Tzus were more likely than females to have skin and musculoskeletal disorders (conditions affecting bones, muscles and joints), while female Shih Tzus were more likely be diagnosed with hernias (when internal tissues push out through weakened muscle tissues). Shih Tzus had higher prevalence of anal sac impaction, umbilical hernias and eye problems than previously reported in dogs overall, suggesting potential predispositions. The average age at death of Shih Tzus was 12.7 years of age and the most common causes of death were enteropathy (gastrointestinal diseases causing signs such as diarrhoea and vomiting, 7.9%), heart disease (7.9%) and poor quality of life (7.9%).This study demonstrated the value of analysis of veterinary clinical records to increase our understanding of common health problems affecting dogs in the UK. The results can help both current and prospective Shih Tzu owners, and veterinarians, in prioritising preventative healthcare for Shih Tzus. For example, the most common disorder in Shih Tzus was periodontal disease, suggesting that increased preventative dental checkups and toothbrushing could improve welfare, especially if implemented from an early age.