The population of pedigree dogs registered with The Kennel Club in the United Kingdom has been shrinking for more than three decades, and the shrinking has accelerated in recent years. A new analysis of the club’s complete electronic database, covering 11 million dogs across all 222 recognised breeds between 1990 and 2021, found that the registered population declined by an estimated 0.89 percent each year over the full period, and by 1.29 percent each year between 2010 and 2021. The figures come from a study published in the journal Companion Animal Health and Genetics, which used a meta-analysis to pool estimates from individual breeds rather than relying on registration totals dominated by a handful of large breeds.
Across 221 breeds, 1,583,217 unique litters were used in the analyses, ranging from a single litter in the Pyrenean Mastiff to 173,855 litters in the Labrador Retriever. The mean breed size across the whole pedigree records was 50,268 dogs, ranging from 56 American Water Spaniels to 1,408,204 Labrador Retrievers.
The overall decline masked enormous variation between breeds. In the analysis covering 1990 to 2021, which included 159 breeds with sufficient data, 123 breeds showed population changes significantly different from zero. Of these, 84 breeds, or 68.3 percent, experienced significant decline, while 39 breeds grew significantly. The Yorkshire Terrier showed the largest decline, losing an estimated 10.6 percent of its registered population each year, while the French Bulldog recorded the largest growth at 22.1 percent annually. Between 2010 and 2021 the pattern intensified: 12 breeds declined by more than 10 percent each year, with the Pyrenean Sheepdog (Long Haired) falling fastest at 16.9 percent annually, while the French Bulldog’s growth accelerated to 34.9 percent per year.
Among the ten most numerous breeds, five showed no significant change between 2010 and 2021: the Labrador Retriever, Cocker Spaniel, English Springer Spaniel, Staffordshire Bull Terrier and Pug. Four increased significantly, including the French Bulldog, the Miniature Smooth-Haired Dachshund at 17.4 percent annually, the Bulldog at 11.7 percent and the Golden Retriever at 2.8 percent. The German Shepherd Dog was the only top ten breed to decline, at 2.5 percent each year. The pooled estimate across the top ten breeds suggested a 5.8 percent annual increase, but this was not statistically significant, indicating that the overall decline is driven by the many smaller breeds rather than the popular ones.
A central finding concerns how few registered dogs are actually bred from. Across 210 breeds with adequate data, only 13.7 percent of KC-registered dogs born between 2005 and 2015 were used in breeding. For males born in 2015, the figure was lower still, at 6.3 percent across 177 breeds. In the top ten breeds, 6.6 percent of males were bred from, ranging from 11.5 percent in the French Bulldog to 3.1 percent in the Golden Retriever. The percentage varied widely even between breeds of similar size: Japanese Chin and the Nova Scotia Duck Tolling Retriever had nearly identical numbers of registered males born in 2015, at 96 and 97 respectively, yet 18.7 percent of Japanese Chin males were bred from compared with 3.1 percent of Nova Scotia Duck Tolling Retriever males.
The study also tracked the characteristics of dogs chosen as parents. Dogs awarded a Studbook number, or SBN, for success in Kennel Club activities such as conformation showing, field trials, agility, obedience and working trials, made up only 5.1 percent of the whole pedigree records across 173 breeds. Yet their influence on breeding was disproportionate: 28.2 percent of all litters across 143 breeds had at least one parent with an SBN, and the pooled breed-level percentage reached 48.0 percent. Sires with an SBN produced on average 2.9 more litters than those without one. However, the use of purpose-bred dogs in breeding is declining, falling by an estimated 1.6 percent each year across 143 breeds, and by 4.8 percent annually in the top ten breeds, with the French Bulldog showing the steepest drop at 12.4 percent per year.
Imported dogs are moving in the opposite direction. The number of KC-registered imports grew by an estimated 6.5 percent each year between 1990 and 2021, and their use in breeding rose sharply, particularly after amendments to the Pet Travel Scheme in 2012 reduced the minimum age at which dogs could be brought into the UK from EU and listed countries. Between 1990 and 2012, 5.9 percent of registered litters had at least one imported parent; between 2013 and 2021 that figure rose to 24.9 percent. More than half of all imports came from just six countries, led by Ireland at 21.0 percent, the Russian Federation at 8.0 percent and Poland at 7.1 percent. Imported sires also produced more litters than national ones, and the proportion of imported dogs among the ten highest-producing sires rose from 22.3 percent for sires born across the full period to 29.8 percent among those born since 2015.
The analysis of the highest-producing sires revealed the scale of popular sire use. The most prolific KC-registered sire of all was an English Springer Spaniel that produced 381 registered litters, or 2,286 puppies, since 1990, against a breed median of one litter. The pooled mean difference between the ten highest-producing sires in each breed and the breed median was 35.2 litters across 175 breeds. The highest-producing sires also started breeding younger than the breed median, by an average of 6.8 months. These patterns matter because the use of popular sires is frequently reported to reduce genetic diversity and spread recessive disorders, and the authors note that management tools such as limits on sire contributions may backfire if replacements are drawn from a popular sire’s close relatives.
A key methodological result is that the breeds cannot be treated as a single population. The meta-analysis found that for the majority of estimates, more than 90 percent of the variation between breeds was attributable to true variability rather than sampling error, and the authors conclude that this does not support the hypothesis of a single pedigree dog population. The study does have limitations the authors acknowledge: the SBN is an imperfect proxy for purpose-bred dogs, the estimates of imported dogs likely undercount dogs imported for pet purposes, and the 2020 to 2021 pandemic puppy boom may have caused the population decline to be underestimated. The researchers also note that the future of imports is uncertain, since The Kennel Club stopped registering dogs from Russia and Belarus in March 2022, and proposed UK legislation on the import of dogs, cats and ferrets may further alter the numbers of legally imported animals.
The practical implications reach beyond the registry itself. The authors argue that the declining registered population, the low percentage of dogs used in breeding and the continued use of popular sires together put the sustainability of the KC-registered pedigree dog population at risk, while the rising use of imported dogs may have a restorative effect on genetic diversity, depending on how genetically divergent the UK populations are from those in exporting countries. Because the variability between breeds is so high, the study’s reference values cannot be applied uniformly. Population management strategies, the authors conclude, must be tailored to the unique demographic circumstances of each breed, accounting for differing genetic reserves, demographic parameters and breeding cultures rather than assuming that what works for the Labrador Retriever will work for the Pyrenean Sheepdog.
Subject of Research: Demographic analysis of Kennel Club-registered pedigree dog breeds in the UK between 1990 and 2021
Article Title: Modern pedigree dogs in the United Kingdom Kennel Club: a journey through shifting population landscapes and demography
Article References: Ilska, J. J., Ryan, P. B., & Tolhurst, D. J. (2025). Modern pedigree dogs in the United Kingdom Kennel Club: a journey through shifting population landscapes and demography. Companion Animal Health and Genetics, 12(1), Article 3. https://doi.org/10.1186/s40575-025-00142-1
Image Credits: AI Generated
DOI: 10.1186/s40575-025-00142-1
Keywords: pedigree dogs, Kennel Club, dog breeding, population decline, genetic diversity, imported dogs, popular sires, Studbook numbers, meta-analysis, breed management, Pet Travel Scheme, UK
News Source: William Thompson. (October 30, 2026). UK pedigree dog numbers shrink as imports reshape breeding. Scienmag.
