Domestication is a well-known example of the relaxation of environmentally-based cognitive selection that leads to reductions in brain size. However, little is known about how brain size evolves after domestication and whether subsequent directional/artificial selection can compensate for domestication effects. The first animal to be domesticated was the dog, and recent directional breeding generated the extensive phenotypic variation among breeds we observe today. Here we use a novel endocranial dataset based on high-resolution CT scans to estimate brain size in 159 dog breeds and analyze how relative brain size varies across breeds in relation to functional selection, longevity, and litter size. In our analyses, we controlled for potential confounding factors such as common descent, gene flow, body size, and skull shape. We found that dogs have consistently smaller relative brain size than wolves supporting the domestication effect, but breeds that are more distantly related to wolves have relatively larger brains than breeds that are more closely related to wolves. Neither functional category, skull shape, longevity, nor litter size was associated with relative brain size, which implies that selection for performing specific tasks, morphology, and life history do not necessarily influence brain size evolution in domesticated species.

The Stanford Dogs dataset contains images of 120 breeds of dogs from around the world. This dataset has been built using images and annotation from ImageNet for the task of fine-grained image categorization. There are 20,580 images, out of which 12,000 are used for training and 8580 for testing. Class labels and bounding box annotations are provided for all the 12,000 images.

To use this dataset:

import tensorflow_datasets as tfds

ds = tfds.load('stanford_dogs', split='train')
for ex in ds.take(4):
 print(ex)

See the guide for more informations on tensorflow_datasets.

https://storage.googleapis.com/tfds-data/visualization/fig/stanford_dogs-0.2.0.png" alt="Visualization" width="500px">

The top dog breed in the UK in 2022, as measured by number of registrations, was the Labrador Retriever breed. Some 44,311 retrievers were newly registered in the UK in 2022. French Bulldogs and Cocker Spaniels rounded out the top three dog breeds in the UK that year.

Surge in UK dog registrations

In 2022, many dog breeds saw a decrease in registrations after large growth in 2021. Over 17 thousand fewer Labrador Retrievers were registered in 2022 than in 2021. Registrations of French Bulldogs and Cocker Spaniels also saw significant decreases in the UK that year.

UK pet food market

Europe and North America produce the most pet food worldwide. In 2022, Europe produced about 11.8 million metric tons of pet food. Though less pet food is produced in North America overall, the United States has the highest pet food revenue worldwide by far. The UK has the second highest revenue, reaching over 6.8 billion U.S. dollars that year.

Breed and breed group sample size (N), sex (F: female, M: male), and mean age (years) of dogs tested in the present study.

In 2020, there were approximately 3.19 million large dogs (over 50 lbs or over 23 kg) in Canadian households as pets. In contrast, small dogs (up to 20 lbs or 9 kg) had a total population of around 1.97 million.

Over the five years to 2024, increases in both competition and public disapproval have threatened the Dog and Pet Breeders industry. This industry includes various operations, from small independent home breeders to large USDA-certified breeding facilities. However, the industry also comprises unlicensed puppy mills, often using inhumane practices to reduce costs and maximize profit. Recent attention to these operations has hurt the overall industry's reputation. In 2017, the "Adopt, Don't Shop" campaign emphasized the ethical benefits of getting pets from shelters and adoption groups rather than pet stores. This campaign has led many pet stores to no longer work with breeders and instead host adoption events with local shelters. Through the end of 2024, industry revenue is expected to grow at an annualized rate of 2.6% to $3.1 billion, including an estimated 0.9% decline in 2024. The breeding industry's trajectory has been mixed with challenges. Stringent regulations like those mandated by the Animal Welfare Act have kept most breeders operating on a small scale, with only a tiny fraction exceeding the threshold for requiring USDA licensing. The public's growing scrutiny of puppy mills and other inhumane conditions has pressured breeders to maintain higher quality standards. Some medium-sized breeders will likely seek USDA certification to improve their reputation and gain legitimacy. Higher standards and requirements will enable these breeders to increase their profits. Heightening veterinary services and pet essentials costs will likely strain household budgets, leading to more careful spending on pet purchases. Demographic trends suggest older populations might shy away from new pets, while younger generations lean towards pet adoption, driven by ethical considerations. Legislative pressures and higher public awareness are expected to push the industry towards more stringent welfare standards. While adoption campaigns and regulatory constraints present formidable challenges, purebred breeders may still find sustained demand from consumers looking for specific traits and appearance. Through the end of 2029, industry revenue is projected to fall at an annualized rate of 0.4% to $3.0 billion.

Body size is an important trait in companion animals. Recently, a primitive Japanese dog breed, the Shiba Inu, has experienced artificial selection for smaller body size, resulting in the “Mame Shiba Inu” breed. To identify loci and genes that might explain the difference in the body size of these Shiba Inu dogs, we applied whole genome sequencing of pooled samples (pool-seq) on both Shiba Inu and Mame Shiba Inu. We identified a total of 13,618,261 unique SNPs in the genomes of these two breeds of dog. Using selective sweep approaches, including FST, Hp and XP-CLR with sliding windows, we identified a total of 12 genomic windows that show signatures of selection that overlap with nine genes (PRDM16, ZNF382, ZNF461, ERGIC2, ENSCAFG00000033351, CCDC61, ALDH3A2, ENSCAFG00000011141, and ENSCAFG00000018533). These results provide candidate genes and specific sites that might be associated with body size in dogs. Some of these genes are associated with body size in other mammals, but 8 of the 9 genes are novel candidate genes that need further study.

Maltese dogs are the most common dog breed owned in South Korea, according to a survey conducted in 2023, with around 26 percent of respondents answering to own such a dog. The market for pets and pet products in South Korea has continued to grow over the last years in Korea and, according to forecasts, will continue to do so for the next six years. Dog population in South Korea Just as the pet market size has grown, the dog population in South Korea has also experienced an upward trend, with almost 5.5 million dogs owned as pets in 2022. While the number of new dog registrations decreased, it was still an elevated level compared to before the COVID-19 pandemic. Dog registrations became mandatory in 2014 and dog owners have to follow up with multiple veterinarian checks. Reasons for this policy were, among others, to reduce the number of stray dogs in cities, such as Seoul, and simplify the recovery of lost dogs. Pet food market According to a survey among pet owners, the preferred type of dog food was dry food. Dry food can be easily imported from other countries and in 2023, South Korea imported most of its pet food from the U.S. The average monthly spending on other pet related items in South Korea amounted to close to nine thousand South Korean won in 2023.

The dataset you have consists of a collection of images of different dog breeds that were obtained from the web. The images showcase a variety of dog breeds with different physical characteristics such as size, shape, color, and fur type. The images were gathered from various online sources, and they may vary in quality, resolution, and orientation.

The dataset provides a valuable resource for researchers and developers interested in studying and developing computer vision and machine learning algorithms for image recognition, object detection, and classification. The images can be used to train and test machine learning models to accurately identify and classify different dog breeds.

The dataset includes a diverse range of dog breeds, including but not limited to Labrador Retriever, German Shepherd, Bulldog, Beagle, Rottweiler, and many more. Each breed is represented by multiple images, taken from different angles and in different poses, to capture as much information about the breed's physical features as possible.

The basic tenets of the evolutionary theories of senescence are well supported. However, there has been little progress in determining the relative influences of mutation accumulation and life history optimisation. The causes of the well-established inverse relationship between lifespan and body size across dog breeds are used here to test these two classes of theories. The lifespan-body size relationship is confirmed for the first time after controlling for breed phylogeny. The lifespan-body size relationship cannot be explained by evolutionary responses to differences in extrinsic mortality, either of contemporary breeds or of breeds at their establishment. The development of breeds larger and smaller than ancestral grey wolves has occurred through changes in early growth rate. This may explain the increase in the minimum age-dependent mortality rate with breed body size and thus higher age-dependent mortality throughout adult life. The main cause of this mortality is cancer. These patterns are consistent with the optimisation of life history as described by the disposable soma theory of the evolution of ageing. The dog breed lifespan-body size relationship may be the result of the evolution of greater defence against cancer lagging behind the rapid increase in body size during recent breed establishment. Methods Data are from published sources.

The ‘nose’ refers to the nose leather, but can constitute a large proportion of the muzzle length in brachycephalic dogs.

*********** were the most popular dogs in Japan, as revealed in a survey panel by Rakuten Insight conducted between April and May 2025. The upper ranking was predominantly occupied by dog breeds with small body sizes, while the Japanese breed Shiba Inu ranked fourth, kept by **** percent of respondents.

Additional file 3: Figure S1. Population size of the Leonberger breed between the years 1920–2016. The blue, yellow, and green lines represent the number of breeding males, breeding females, and puppies they produced per year, respectively. The red dashed line represents the number of expected parent pairs for the given number of born puppies per year, assuming the average litter size of 6.5 puppies. Panel (a) shows the increasing population size from 1920 to 1978 and the apparent bottleneck around 1946. In the 1970s, the number of dogs born started to increase rapidly whereas the number of breeding males used started to decrease. Panel (b) shows the continuously increasing population from 1979 to 2016. Note that the number of dams is more or less as expected but the number of sires constantly decreases to about half of that of the dams in recent years, illustrating the popular sire syndrome.

Global Small Breed Dog Clothing market size 2025 is $778 Million whereas according out published study it will reach to $1268.37 Million by 2033. Small Breed Dog Clothing market will be growing at a CAGR of 6.3% during 2025 to 2033.

The global dog crate market is experiencing robust growth, driven by increasing pet ownership, heightened awareness of pet safety and security, and a rising demand for convenient and comfortable pet containment solutions. The market size in 2025 is estimated at $500 million, showcasing significant potential for expansion. Considering a projected Compound Annual Growth Rate (CAGR) of 6% from 2025 to 2033, the market is expected to reach approximately $800 million by 2033. This growth is fueled by several key trends, including the increasing popularity of smaller dog breeds requiring specialized crates, the rise of innovative crate designs incorporating smart features, and a growing preference for aesthetically pleasing crates that seamlessly integrate into home décor. The market segmentation is diverse, encompassing various crate types (wire, plastic, soft-sided), sizes, and materials, catering to a broad range of dog breeds and owner preferences. Despite the optimistic outlook, the market faces certain restraints. These include fluctuating raw material prices, concerns about the environmental impact of crate manufacturing, and potential competition from alternative pet containment methods. However, ongoing innovation in crate design and materials, coupled with the enduring demand for safe and reliable pet containment, will continue to drive market growth. Key players such as Midmark, American Kennel Club, and others, are actively contributing to this growth through product diversification and strategic expansions. Their focus on product innovation and enhanced consumer experience is pivotal in shaping the market's future trajectory.

Dog Food for Small Breeds Market Outlook

The global market size for dog food catered towards small breeds was estimated at USD 8.2 billion in 2023 and is projected to reach USD 12.5 billion by 2032, growing at a CAGR of 4.6% over the forecast period. This growth is driven by several factors, including increasing pet ownership, rising disposable incomes, and a growing awareness of the dietary needs specific to small breeds.

One of the primary growth factors in this market is the increasing number of pet owners around the world. According to various surveys, millennials are leading the charge in pet adoption, with a significant number of these new pet owners opting for smaller dog breeds due to their suitability for urban living conditions. This surge in adoption rates directly translates into a higher demand for specialized dog food products tailored specifically for small breed dogs, driving market growth.

Another critical factor contributing to the market's expansion is the rising disposable incomes across both developed and developing nations. As pet owners increasingly view their pets as family members, they are more willing to spend on premium and specialized food products. This trend is particularly evident in urban areas where higher disposable incomes allow pet owners to opt for higher-priced, nutritionally optimized dog food options that cater to the specific dietary needs of small breeds.

Growing awareness about the unique dietary requirements of small breed dogs is also propelling market growth. Nutritionists and veterinarians emphasize that small breeds have faster metabolisms and specific health needs that can be addressed through specialized diets. Consequently, pet food manufacturers are focusing on producing dog foods that offer balanced nutrition, improved palatability, and targeted health benefits, further boosting market demand.

Regionally, North America remains a dominant player in the global dog food market for small breeds, driven by high pet ownership rates and significant consumer spending on pet care. However, the Asia Pacific region is expected to witness the fastest growth during the forecast period due to increasing urbanization, rising disposable incomes, and a growing trend of pet adoption. Countries like China and India are particularly noteworthy for their burgeoning pet care markets.

Product Type Analysis

The dog food market for small breeds can be segmented into various product types, including dry dog food, wet dog food, semi-moist dog food, and others. Each of these segments has its unique advantages and market appeal, which contribute to their respective growth trajectories. Dry dog food holds the largest market share due to its convenience, longer shelf life, and cost-effectiveness. Pet owners find dry dog food easier to store and serve, making it a popular choice for those with busy lifestyles.

Wet dog food, on the other hand, is gaining traction for its high palatability and moisture content, which is particularly beneficial for small breeds that may have difficulties in chewing dry kibble. Wet dog food is often enriched with essential nutrients and offers a more varied texture, making it an attractive option for picky eaters. Increased consumer awareness about the importance of hydration in small breeds also drives the growth of this segment.

Semi-moist dog food represents a smaller share of the market but is appreciated for its balance between the convenience of dry food and the palatability of wet food. It is often formulated to be chewy and appealing, which can be particularly beneficial for small breed dogs with dental issues or those transitioning from wet to dry food. This segment is expected to grow steadily as manufacturers innovate to improve the nutritional profile and shelf life of semi-moist products.

Other product types in this market include specialty formulas designed for specific health conditions or dietary preferences, such as grain-free or hypoallergenic options. These niche products cater to the growing segment of health-conscious pet owners who are willing to invest in premium dog food to ensure the well-being of their small breed pets. As awareness of pet health continues to rise, the demand for these specialized products is expected to grow.

Report Scope

The global weight management dog food market is experiencing robust growth, driven by increasing pet obesity rates and a rising awareness among pet owners regarding canine health. The market, estimated at $2.5 billion in 2025, is projected to expand at a Compound Annual Growth Rate (CAGR) of 7% from 2025 to 2033. This growth is fueled by several factors, including the increasing humanization of pets, leading to more indulgent feeding habits, and the growing availability of specialized weight management formulas. The market is segmented by food type (dry and wet) and dog breed size (small, medium, and large), with dry food currently dominating due to its longer shelf life and affordability. Premium brands offering high-quality ingredients and tailored nutritional profiles are capturing significant market share, indicating a consumer preference for specialized products that address specific health concerns. The market's growth is further supported by the expanding veterinary services sector, with veterinarians increasingly recommending weight management diets as part of comprehensive pet care plans. Geographic variations exist, with North America and Europe representing the largest markets due to higher pet ownership rates and greater consumer spending power on pet products. However, emerging markets in Asia-Pacific are demonstrating significant growth potential driven by rising disposable incomes and increasing pet adoption. While the market faces some constraints, such as price sensitivity in certain regions and the potential for competition from generic brands, the overall outlook remains positive, with continued expansion expected throughout the forecast period. Key players in this competitive landscape are constantly innovating, introducing new formulations, and expanding their distribution channels to maintain a strong market presence. The focus on natural ingredients, functional benefits, and veterinary endorsements will continue shaping the trajectory of this dynamic market.

Prominent differences in aging among and within species present an evolutionary puzzle. The theories proposed to explain evolutionary differences in aging are based on the axiom that selection maximizes fitness, not necessarily lifespan. This implies trade-offs between investment into self-maintenance and investment into reproduction, where high investment into growth and current reproduction are associated with short lifespans. Fast growth and large adult size are related with shorter lifespans in the domestic dog, a bourgeoning model in aging research, however, whether reproduction influences lifespan in this system remains unknown. Here we test the relationship between reproduction and differences in lifespan among dog breeds, controlling simultaneously for shared ancestry and recent gene flow. We found that shared ancestry explains a higher proportion of the among-breed variation in life history traits, in comparison with recent gene flow. Our results also show that reproductive investment negatively impacts lifespan, and more strongly so in large breeds, an effect that is not merely a correlated response of adult size. These results suggest that basic life history trade-offs are apparent in a domestic animal whose diversity is the result of artificial selection and that among-breed differences in lifespan are due to a combination of size and reproduction. Methods Data were collected from published sources (citations of these appear in the README file) and from the website of the American Kennel Club (AKC). To curate the data, we ran a series of comparisons (Pearson correlation analyses) to ensure repeatability among sources (for details, see the methods section of the article).

Humans do not respond to the pain of all humans equally; physical appearance and associated group identity affect how people respond to the pain of others. Here we ask if a similar differential response occurs when humans evaluate different individuals of another species. Beliefs about pain in pet dogs (Canis familiaris) provide a powerful test, since dogs vary so much in size, shape, and color, and are often associated with behavioral stereotypes. Using an on-line survey, we asked both the general public and veterinarians to rate pain sensitivity in 28 different dog breeds, identified only by their pictures. We found that both the general public and veterinarians rated smaller dogs (i.e. based on height and weight) as being more sensitive to pain; the general public respondents rated breeds associated with breed specific legislation as having lower pain sensitivity. While there is currently no known physiological basis for such breed-level differences, over 90% of respondents from both groups indicated belief in differences in pain sensitivity among dog breeds. We discuss how these results inform theories of human social discrimination and suggest that the perception of breed-level differences in pain sensitivity may affect the recognition and management of painful conditions in dogs.