Published: 24 Jan 2024 | Last Updated: 24 Jan 2024 00:01:22

New research from the Royal Veterinary College (RVC) has found the most common conditions diagnosed in Shih Tzu dogs in the UK are periodontal disease (inflammation of the gums and tissue around the teeth), anal sac impaction and ear disorders. While the findings suggest that the breed is predisposed to a number of conditions, the overall disorder profile of the Shih Tzu is surprisingly different and better than many other common flat-faced breeds.

The Shih Tzu is the seventh most common dog breed in the UK, with an estimated UK population of more than 300,000 that accounts for 3% of all UK dogs¹. Shih Tzu are a flat-faced breed, also known as a brachycephalic breed, with this extreme body shape linked to number of serious eye and breathing health issues because the short muzzle causes excessive facial skin folds and shallow eye sockets. However, until now, there has been limited information available on the most common health issues in the Shih Tzu breed.

The new study was led by the RVC’s VetCompass Research Programme and investigated anonymised clinical information on 11,082 (3.29%) Shih Tzus from an overall study population of 336,865 dogs under veterinary care during 2016.

Dental (periodontal) disease was the most recorded disorder in Shih Tzu, with 9.5% of dogs diagnosed with the condition each year. Periodontal disease was more common in older dogs, emphasising to owners that extra veterinary and home care is needed to protect the dental health of their Shih Tzu ages.

The other common disorders found in Shih Tzu were anal sac impaction (7.4%), ear disorders (5.5%), otitis externa (4.7%; inflamed ear canal), vomiting (4.4%) and umbilical hernias (3.9%; when internal tissues push out through weakened muscle tissues).

However, despite the Shih Tzu being a flat-faced breed, their overall health profile of common disorders was quite similar to the health profiles of non-flat-faced dogs previously reported ². This suggests the Shih Tzu is much less severely affected by its flat-faced conformation than other common brachycephalic breeds such as French Bulldogs, English Bulldogs and Pugs. For example, the reported frequency of otitis externa in French Bulldogs was 14%, almost three times the level reported for Shih Tzus (4.7%)³, while the frequency of corneal (eye surface) disorders in Pugs was 8.7%, more than double that reported in Shih Tzus (3.5%).

Other key findings include:

• The frequency of anal sac impaction, umbilical hernias and eyes problems were substantially higher in Shih Tzu dogs than previously identified in dogs overall²
• Female Shih Tzu dogs had a higher probability of umbilical hernia, while males had a higher probability of aggression, heart murmur, skin lesions and haircoat disorders
• The average adult bodyweight for Shih Tzu overall was 7.9kg. The average bodyweight of males (8.5kg) was heavier than for females (7.3kg)
• The most common causes of death were bowel diseases (diarrhoea, vomiting etc.) (9.6%), heart disease (9.6%) and poor quality of life (9.6%)
• The overall average age at death of Shih Tzu was 12.7 years. This is longer than the average of 11.2 years reported for dogs overall in the UK⁴

This information on common disorders can help vets, breeders and owners prioritise prevention and management of these disorders in Shih Tzu. Although some disorder predispositions were identified in Shih Tzu such as eye and anal sac problems, the overall longevity and disorder patterns were not that dissimilar to dogs overall² suggesting that Shih Tzu can be considered as a more typical dog in terms of common health issues compared to other popular flat-faced breeds.

Dr Fiona Dale, VetCompass Epidemiologist at the RVC and lead author of the paper, said:

“Shih Tzu are small, popular dogs in the UK. While we found that the top disorders in the breed were similar to those commonly reported in dogs overall, Shih Tzu appear to be predisposed to a number of conditions including eye conditions. In order to effectively prioritise the welfare of their dogs, owners of Shih Tzu should be vigilant for eye problems to allow earlier diagnosis and treatment.”

Dr Dan O’Neill, Associate Professor in Companion Animal Epidemiology at the RVC and co-author of the paper, said:

“Flat faces in dogs have been linked to several serious health problems, but this new study highlights that the health profile of each flat-faced breed can be quite unique. The 12.7 year longevity of Shih Tzu suggests the overall health of the breed is much less severely compromised than other flat-faced breeds such as French Bulldogs, English Bulldogs and Pugs that live less than eight years on average.”

Bill Lambert, Health, Welfare and Breeding Services Executive at The Kennel Club, which helped to fund the research, added:

“This research enables better understanding of breed-specific health concerns, and these findings will feed into the Shih Tzu breed health and conservation plan, managed by The Kennel Club to identify and monitor any concerns, and continue to improve health.

“We’re pleased this study indicates that most disorders faced by Shih Tzu are fairly common for all dogs, and that there don’t seem to be any prevalent extreme health conditions, including those which can be associated with other brachycephalic breeds. It remains crucial, however, that all puppy buyers do thorough research regarding health and go to a responsible breeder; this plays an important part in improving the health and welfare of all breeds, now and in generations to come.”

Main Reference

Dale, F., Brodbelt, D. C., West, G., Church, D. B., Lee Y. H & O’Neill, D. G. (2023) Demography, common disorders and mortality of Shih Tzu dogs under primary veterinary care in the UK. Canine Medicine and Genetics

The full paper is available from 1:00 am CET / 8:00 am China Standard Time /12:00 am GMT on 24th January 2024 and can be accessed at: DOI: 10.1186/s40575-023-00135-y.

Additional References

1. O'Neill DG, McMillan KM, Church DB, Brodbelt DC. Dog breeds and conformations in the UK in 2019: VetCompass canine demography and some consequent welfare implications. PLOS ONE. 2023;18(7):e0288081.

2. O’Neill DG, James H, Brodbelt DC, Church DB, Pegram C. Prevalence of commonly diagnosed disorders in UK dogs under primary veterinary care: results and applications. BMC Veterinary Research. 2021;17(1):69.

3. O’Neill DG, Baral L, Church DB, Brodbelt DC, Packer RMA. Demography and disorders of the French Bulldog population under primary veterinary care in the UK in 2013. Canine Genetics and Epidemiology. 2018;5(1):3.

4. Teng KT-y, Brodbelt DC, Pegram C, Church DB, O’Neill DG. Life tables of annual life expectancy and mortality for companion dogs in the United Kingdom. Scientific Reports. 2022;12(1):6415.

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About the RVC

• The Royal Veterinary College (RVC) is the UK's largest and longest established independent veterinary school and is a Member Institution of the University of London.
• It is one of the few veterinary schools in the world that hold accreditations from the RCVS in the UK (with reciprocal recognition from the AVBC for Australasia, the VCI for Ireland and the SAVC for South Africa), the EAEVE in the EU, and the AVMA in the USA and Canada.
• The RVC is ranked as the top veterinary school in the world in the QS World University Rankings by subject, 2023.
• The RVC offers undergraduate and postgraduate programmes in veterinary medicine, veterinary nursing and biological sciences.
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• The RVC provides animal owners and the veterinary profession with access to expert veterinary care and advice through its teaching hospitals and first opinion practices in London and Hertfordshire.
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About the VetCompass™ Programme

VetCompass™ (The Veterinary Companion Animal Surveillance System) is an epidemiological research programme at the Royal Veterinary College (RVC) which investigates anonymised clinical records from veterinary practices to generate evidence to support improved animal welfare. VetCompass shares information from more than 1,800 veterinary practices in the UK (over 30% of all UK practices) covering over 28 million companion and equine animals. To date, VetCompass™ has led to over 120 peer-reviewed publications that have supported welfare-focused work across the range of animal stakeholders including the wider general public, owners, breeders, academics, animal charities, universities and government.

For more information, visit: https://www.rvc.ac.uk/vetcompass

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