Yorkshire Terriers made up 28,032 of the 905,542 dogs under primary veterinary care in the UK in 2016, representing 3.10 percent of the national population of dogs seen by participating clinics. That figure comes from the largest study to date of the breed’s overall health, which drew on anonymised electronic health records from the VetCompass Programme to characterise the demography, common disorders and longevity of Yorkshire Terriers across Britain. The results, published in the open-access journal Companion Animal Health and Genetics, paint a picture of a small, long-lived breed whose popularity is quietly slipping, even as its veterinary record reveals both distinctive strengths and predictable vulnerabilities.
The demographic data show a breed in gradual retreat. Annual proportional birth rates for Yorkshire Terriers fell from 3.54 percent of all dogs born in 2005 to 2.15 percent in 2016. That decline is far shallower than the collapse in Kennel Club registrations, which dropped by a factor of five over the past decade, from 2,077 registrations, or 0.93 percent of all registrations, in 2013 to just 495, or 0.18 percent, in 2022. The researchers suggest that the pedigree subset of the breed, bred to meet the KC breed standard, is suffering the steepest decline, while the wider, often unregistered population of Yorkshire Terriers remains comparatively common. At 3.10 percent of all dogs under veterinary care in 2016, and 2.37 percent in a follow-up study of 2019 data, Yorkshire Terriers still ranked among the ten most common breeds in Britain.
That divergence between pedigree and wider populations carries practical weight. The Kennel Club breed standard specifies a maximum bodyweight of 3.2 kilograms for the Yorkshire Terrier, yet the median adult bodyweight recorded in this study was 5.06 kilograms, with an interquartile range of 3.81 to 6.49 kilograms and a full range stretching from 1.01 to 15.00 kilograms. Three quarters of the dogs weighed more than 3.81 kilograms. Males were consistently heavier than females, with a median adult bodyweight of 5.50 kilograms against 4.67 kilograms for females, a difference that was statistically significant. Bodyweight curves built from more than 211,000 recorded weights showed that Yorkshire Terriers grow rapidly in their first year and continue gaining weight until roughly five years of age.
The health findings rest on a detailed manual review of the clinical records of a random sample of 3,308 Yorkshire Terriers, or 11.80 percent of the breed’s study population. Among these dogs, 2,157, or 65.21 percent, had at least one disorder recorded during 2016, producing 4,212 unique disorder events spread across 356 fine-level diagnostic terms. The median annual disorder count per dog was one. The single most commonly diagnosed disorder was periodontal disease, affecting 21.10 percent of the sampled dogs, with a 95 percent confidence interval of 19.71 to 22.49 percent. Overgrown nails followed at 6.47 percent, then anal sac impaction at 3.99 percent, overweight or obesity at 3.72 percent, and persistent deciduous teeth at 3.57 percent.
When diagnoses were grouped into broader categories, dental disorder led at 26.84 percent, followed by enteropathy at 9.98 percent, skin disorders at 9.28 percent, claw and nail disorders at 8.31 percent, and ophthalmological disorders at 6.62 percent. Sex differences emerged across the most common diagnoses: females had a greater probability of mammary and skin masses at the fine level, while males were more likely to be diagnosed with periodontal disease, aggression, heart murmur, claw injury and cryptorchidism. At the grouped level, females showed more mass, endocrine and female reproductive disorders, whereas males showed more dental, anal sac, behavioural, upper respiratory tract, heart and male reproductive disorders. Disorder prevalence also shifted with age, with ten of fifteen tracked disorder groups varying significantly across three age bands covering dogs under three years, three to ten years, and over ten years.
Three conditions stand out as apparent breed predispositions. Periodontal disease in Yorkshire Terriers, at 21.10 percent, is nearly twice the 12.52 percent prevalence reported for UK dogs overall in a previous study of 22,333 dogs, and even after accounting for age in multivariable analysis, Yorkshire Terriers in that earlier work had 2.16 times greater odds of the condition than crossbred dogs. Persistent deciduous teeth, at 3.57 percent, run against an overall canine prevalence of 1.01 percent, placing the breed’s rate at more than three times the general figure. Patellar luxation, a dislocation of the kneecap that can be developmental or traumatic, affected 3.42 percent of Yorkshire Terriers in the current study, compared with 1.04 percent in dogs overall, and earlier research has reported 5.5 times greater odds of the condition in the breed relative to crossbreds.
The mortality data underline the breed’s most celebrated trait: longevity. Among the 464 sampled Yorkshire Terriers that died during the study period, the median age at death was 13.56 years, with an interquartile range of 11.30 to 15.15 years and a range from 0.06 to 19.08 years. Longevity did not differ significantly between females and males. This figure exceeds the 12.0-year median longevity previously reported for UK dogs overall by more than eighteen months, and it aligns with life-table analyses that placed the Yorkshire Terrier second among eighteen common breeds for life expectancy from the first year of life, at 12.54 years, behind only the Jack Russell Terrier at 12.72 years. Among deaths with a recorded method, 85.71 percent were euthanised and 14.29 percent were unassisted.
The leading biomedical causes of death were brain disorders, accounting for 9.79 percent of the 378 deaths with a reported cause, kidney disorders at 8.73 percent, and appetite disorders at 8.20 percent. The authors caution that high longevity alone does not guarantee a long healthspan, since aging itself is a strong risk factor for degenerative, inflammatory and neoplastic disorders that can erode quality of life, and small dogs generally hold a lifespan advantage over large breeds regardless of breed-specific health. Small body size, possibly linked to differences in glycolytic metabolism and DNA damage rates in larger dogs, may partially explain the Yorkshire Terrier’s relative longevity, but the researchers note that further study is warranted to clarify the true state of the breed’s health.
The study’s design shapes how its findings should be read. It is a descriptive prevalence study of dogs under primary veterinary care at VetCompass participating practices during 2016, with ethical approval from the RVC Social Science Research Ethical Review Board. It reports the frequency of annual diagnosis rather than analytically comparing risk between Yorkshire Terriers and other dogs from the same denominator population, so apparent prevalence may underestimate true prevalence where disorders are complex or costly to diagnose. No distinction was made between pre-existing and incident presentations, and data on disorder duration and severity, which a fuller welfare assessment would require, were not extracted. The relative contributions of intrinsic risk in the dogs themselves and extrinsic risk from environment or owner care remain unknown.
Even with those limits, the study offers a consolidated evidence base for anyone responsible for the breed’s welfare. Its authors suggest that owners and veterinary professionals who recognise the breed’s elevated risks of periodontal disease, persistent deciduous teeth and patellar luxation may detect these problems earlier, and that daily preventative dental care, early monitoring of tooth eruption and informed discussion of kneecap problems could all follow from that awareness. On the demographic side, the contrast between a shrinking pedigree population and a more stable wider population raises questions about genetic diversity and the future of the KC-registered subset, which may soon qualify as a vulnerable native breed under the threshold of fewer than 300 annual registrations. For a breed that has outlived nearly all of its peers, the challenge now appears to be less about survival than about sustaining the population that makes that longevity possible.
Subject of Research: Demography, common disorders and longevity of Yorkshire Terriers under UK primary veterinary care
Article Title: Yorkshire Terriers under primary veterinary care in the UK – demography and disorders
Article References: O’Neill, D. G., Witkowska, S. D., Brodbelt, D. C., Church, D. B., & Engdahl, K. S. (2025). Yorkshire Terriers under primary veterinary care in the UK – demography and disorders. Companion Animal Health and Genetics, 12(1), Article 6. https://doi.org/10.1186/s40575-025-00145-y
Image Credits: AI Generated
DOI: 10.1186/s40575-025-00145-y
Keywords: Yorkshire Terrier, VetCompass, dog health, periodontal disease, patellar luxation, longevity, Kennel Club, veterinary epidemiology, persistent deciduous teeth, UK dog population, breed demography, mortality
News Source: William Thompson. (October 29, 2026). Britain’s Yorkshire Terriers Are Living Longer but Becoming Less Popular. Scienmag.
