School of Health in Social Science

Effects of the illegal puppy trade

This was undertaken in collaboration with the Scottish SPCA as part of their campaign to end the illegal puppy trade. Our research revealed the effects of puppy farming, intensive dog breeding regimens, on dog behaviour.


Front cover of the briefing paper on the illegal puppy trade, with a photograph of a puppy in a cage

This project investigated the effects of intensive dog breeding regimens, also known as 'puppy farming', on the behaviour of dogs as reported by their owners. Puppy farming is an illegal practice where the welfare of dogs is not a priority, if it is taken into account at all. This means puppies are typically raised in stressful and cramped conditions, without adequate human contact, and often without veterinary treatment. Because this occurs during early life, which is one of the most sensitive periods for behavioural development, it has long-term impacts for the behaviour of the dogs within the family home. Specifically, puppy farming will not properly socialise dogs to humans and other environmental factors, increasing fear to novelty when they are adults. This can have serious consequences, as fear-based behavioural problems and especially aggression can put the safety of family members at risk (perhaps especially children). 

Our study

Our findings confirm that puppy farming has a range of serious impacts on dogs in the family home. These include increased behavioural problems for 11 of the 14 scales used in the study, especially in relation to fear responses, and medical conditions or illnesses. To further investigate the way owners can mitigate these effects, we tested whether dog walking or taking part in training activities could impact the behavioural outcomes of these dogs, and found that more frequent walking did decrease negative behaviours, while training seemed to have an interaction effect on behavioural score. The results for this study are currently being reviewed and will hopefully be published later this year. 


The findings of the study were presented at a high profile conference jointly organised by the University of Edinburgh and the Scottish SPCA in November 2017:

SPCA’s unite to tackle illegal puppy trade ahead of Christmas influx | SSPCA (


Press coverage


The outcomes of the conference (including a summary of our research findings) can be found in our briefing paper: