Urolithiasis is a common problem in dogs. Although risk factors for formation of uroliths of different mineral composition have been studied extensively most reports have emanated from the United States and mainland Europe. The results from these studies may not be applicable to dogs in the UK, particularly in respect of breed predisposition, because of its relatively closed breeding population and differences in breed popularity. Canine uroliths submitted to Hills Pet Nutrition UK, for quantitative analysis by the Minnesota Urolith Centre, from January 1996 until December 2006 were included in this study. In total 14,066 canine uroliths were available for analysis. The number of uroliths submitted increased annually from 33 in 1996 to 1922 in 2006. The majority of uroliths with a predominant (>70%) mineral content of a single type were composed of struvite (49%) or calcium oxalate (31%). Nine percent of uroliths were composed predominantly of urate. Cystine uroliths (3.2%) were relatively common compared with previous studies. The prevalence of struvite uroliths decreased from 54% to 46% between 1996 and 1999 and has subsequently has increased again to 50% in 2006. The proportion of calcium oxalate uroliths decreased from 37% in 1999 to 25% in 2006, however, the absolute number of calcium oxalate uroliths has not decreased over this time period. The three breeds of dog most commonly affected with struvite urolithiasis were Shih Tzus, Yorkshire terriers and Jack Russell terriers. Yorkshire terriers, West Highland White terriers and Jack Russell terriers were the breeds most commonly affected by calcium oxalate uroliths and Dalmatians, Yorkshire terriers and Shih Tzus were most commonly affected by ammonium urate uroliths. Although the relative frequency of struvite and oxalate stones is changing in the UK the pattern of this change appears to be slightly different to that reported in previous studies from mainland Europe and the US. The frequency with which Jack Russell terriers are affected with urolithiasis has not been recognised previously and their representation in this study likely reflects the breed popularity in the U.K.