Almost a decade has passed since a DEFRA consultation concluded that existing legislation governing the UK puppy trade was “outdated, inflexible, incompatible with current welfare legislation and cumbersome for both enforcers and businesses”. The rapid outgrowth of the trade’s governing legislature, fuelled by contemporary consumer culture and the high degree of trader anonymity provided by the internet, has enabled a high-volume, untraceable and profit-driven market to evolve. Increased demand for puppies, exacerbated by social media trends and the COVID-19 pandemic, is sustained by an online medium that both encourages and capitalises upon modern-day ‘click-and-collect’ purchase behaviour. Moreover, the internet has only intensified the demand for pedigree and designer crossbreeds, many of which are shown to suffer lifelong physiological disorders caused by the positive phenotyping selection necessary to achieve breed standards. These factors have made puppies an attractively lucrative, low-risk commodity. Evidence of multi-level fraud and organised crime involvement has been revealed along the supply chain, resulting in systemic canine health and welfare issues. Whilst large-scale breeding operations reportedly smuggle unvaccinated puppies onto the British market from endemic (rabies, Leishmania) countries, high densities of pet dogs in urban areas is reportedly leaving high faecal-saturation levels, spreading anthelmic- and antibiotic-resistant pathogens. Meanwhile, unsafe concentrations of ectoparasiticides are detected in rivers and lakes. This review collates evidence from available sources that illustrate the current nature and impact of inadequate regulation in the UK puppy trade, aiming to support stakeholders in their efforts for essential and comprehensive regulatory reform.