New research from the Royal Veterinary College has revealed that puppies bought from illegal or low-welfare sources are more likely to experience health problems later in life, regardless of whether they go on to live in caring home environments. 

These findings provide evidence that can help the public make more informed puppy-buying choices that can reduce the long-term health and welfare risks for their dogs.

For years, legal and public advice have warned that puppies bought from low-welfare sources, such as ‘puppy farms’, or via illegal imports, may face poorer health later in life. However, until now, there has been little evidence to clearly demonstrate these long-term impacts.

To address this gap, the RVC conducted a large-scale longitudinal study of 985 UK puppies acquired during the pandemic, when UK puppy-buying practices deteriorated due to high demand and visiting restrictions. Using online owner questionnaires that explored the health of their dogs during puppyhood and young adulthood, the researchers identified the extent to which early-life experiences and purchasing practices influenced canine health as the dogs grew.

The findings revealed that how a puppy is purchased strongly impacts their future health. Puppies purchased illegally under six weeks old typically suffered almost three additional health problems by 21 months of age, compared to puppies sold at an older age (it is illegal in the UK to sell any puppy aged under 8 weeks). This was identified as the most significant factor for future health. Furthermore, puppies purchased illegally without their mother present suffered 0.3 more health problems compared to puppies sold with their mother present. It is illegal in England, Wales and Scotland to sell a puppy without their mother present under ‘Lucy’s Law’. In addition, puppies bought by a first-time dog owner suffered 0.35 more health problems compared to those bought by an experienced owner.

Buyers who purchase very young puppies or view them without their mother risk being “Pet-fished” — a Department for Environment, Food and Rural Affairs term for sellers misrepresenting a puppy’s origins and concealing poor breeding and welfare conditions. High UK demand for puppies, a lack of due diligence around purchasing by some owners and the increasing commodification of puppies are fuelling increasing levels of low-welfare breeding both in the UK, and in Central and Eastern Europe, where puppies are commonly imported from for the UK market.

This new RVC research also revealed that 91.1% of all the puppies purchased had experienced at least one health issue by 21 months of age, and so all new owners should be prepared for some likely health issues. The most common disorders included digestive issues (75.4%); skin disorders (26.8%); eye disorders (25.1%); upper respiratory conditions (18.5%); and ear disorders (17.6%). Overall, more than half (54.6%) of dogs received veterinary treatment for at least one health problem. Nearly one in four owners (23.5%) reported that they had spent more on veterinary care than they expected. 

These findings highlight the importance of prospective owners being well prepared for the financial and emotional costs of owning a dog, due to the likelihood of them experiencing health problems, even in their early years. Additionally, the extra health risks for puppies purchased when they are too young or when their mother is not present at the sale also show the extra financial, emotional costs for owners, and welfare costs for dogs as a result of these purchasing practices.

The research highlights that health risks begin before a dog even enters its new home, demonstrating the need for informed action by owners during the decision-making stage of the puppy buying process. Improving public awareness of illegal practices and ‘red flags’ of illegal sales, alongside more consistent enforcement of existing legislation, is essential to prevent puppies from being sold from low-welfare breeders when they are too young or without their mothers present. Better preparation and support for prospective owners could help reduce future welfare problems and prevent avoidable distress for both dogs and their owners.

Dr Rowena Packer, Senior Lecturer in Companion Animal Behaviour and Welfare Science at RVC and senior author of the paper, said: “Some people believe that once a puppy is settled into a home and loved, their early weeks of life no longer matter. Our findings don’t support this and show that being bred and reared in low-welfare systems carries lasting negative impacts on canine long-term health. A poor start in life cannot simply be undone.

“Buyers who are unaware or ignore red flags of illegal sales, such as buying a puppy without seeing its mother or taking them home below the legal age for sale, risk setting their dog up for health problems later in life.

“Every puppy buyer has the power to influence the future of dog welfare. By knowing what to look for in a breeder and refusing to support illegal sellers, owners can protect their own dog and countless others within low-welfare breeding systems, helping to bring an end to the illegal puppy trade.”

Dr Marc Abraham OBE, Veterinary Surgeon and Secretariat to the All-Party Parliamentary Dog Advisory Welfare, who led the ‘Lucy’s Law’ campaign to ban third-party commercial puppy dealers, said: “The risks of purchasing a puppy from a legal low-welfare or illegal source include the puppy and/or the parents suffering serious health problems, as well as an increased likelihood of significant behaviour issues too.

“Lucy’s Law is all about providing breeder accountability and transparency, making sure the mother dog and her breeding environment are always visible, making buyers less likely to be misled or scammed, so questionable breeding practices aren’t encouraged.

“Prospective owners should therefore always ask to see the puppy interacting with mum, and the seller knows they’ll be asking to see mum. As well as the legislation, buyer education and awareness is key, as well as what to do in situations when mum isn’t there or the buyer suspects something unethical. Anyone looking for a puppy should always also consider rescue as well.”

Simona Zito, Grants & Programmes Manager at Battersea, who supported this research, said: "By funding studies like this through our grants programme, we aim to give owners the evidence they need to walk away from illegal or low-welfare sellers, choose reputable sources, and help prevent avoidable suffering and relinquishment.”