10 Apr 2026
Researchers show puppies from illegal or low welfare sources remain at greater risk of health problems.

Image: David Davis / Adobe Stock
Puppies acquired from illegal or low welfare sources are at greater risk of future health problems regardless of their subsequent homes, a new study has concluded.
Although fears have grown over many years, RVC researchers say their latest findings offer firm evidence that they hope will help the public to make more informed decisions in the future.
Senior author Rowena Packer 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.”
The warning is based on the analysis of more than 900 puppies purchased in the UK during 2020, which has now been published in the Animal Welfare journal.
It found puppies sold when below six weeks old, before the UK’s legal threshold of eight weeks, typically experienced nearly three times more health problems by the time they were 21 months old than others sold when they were older.
Puppies sold without their mother present – another breach of the legislation – and those bought by first-time owners were also found to be at greater risk, typically experiencing 0.3 and 0.35 additional health problems, respectively.
The paper argued it was “clear further interventions are urgently required” to raise public awareness of factors that indicated puppies were being sold unlawfully.
Dr Packer also warned prospective owners who are either unaware of or disregard issues like that “risk setting their dog up” for future health problems.
She said: “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.”
But the study also called for more to be done to better educate owners before acquiring a puppy to reduce what it called “expectation-mismatch related relinquishments”, plus potential undertreatment that may be linked to wider financial pressures.
While more than 91% of the cohort had experienced at least one health issue before reaching 21 months, only 54.6% reported issues that their dogs had received vet care for.
A total of 64.85% also reported the amount they spent on treatment was in line with their pre-acquisition expectations. The proportion that said they had spent more than they anticipated (23.5%) outnumbered those who had spent less (10.47%) by more than two to one.
The paper said the high proportion of reported health disorders, regardless of whether veterinary advice was sought for them, showed the need for “realistic expectations” among prospective owners.