Feeding practices of dog breeders throughout the reproductive cycle can influence fertility and litter survival, as well as have long-term consequences on the health of puppies. Therefore, we sought to determine the prevalence of dog breeders who feed their animals diets that meet currently accepted nutritional standards for reproduction and early development, and to investigate factors that influence their feeding practices. Using a Web-based questionnaire, we surveyed dog breeders from the U.S. and Canada who were 18 years and older and who breed at least one litter every two years. Information collected included: feeding practices during three life stages (pre-pregnancy, gestation/lactation, and puppy growth); criteria for diet selection; and sources of diet information. Nutritional adequacy of commercial diets was determined by AAFCO (Association of American Feed Control Officials) statements on product labels. During gestation/lactation, 1,659 respondents (85%) reported feeding commercial diets, while 294 (15%) reported feeding home prepared diets. Approximately 17% (131 of 759) of breeders who provided the AAFCO statements from their commercial diet products were feeding inadequate diets intended only for supplemental feeding or for a different life stage. Unsubstantiated marketing claims, particularly those referring to diet ingredients, were reported by many respondents as being factors that influence their feeding practices. Although 68.5% of the breeders viewed veterinarians as a trusted source of diet information, only 34.5% reported consulting them for nutrition information. Given the number of breeders feeding inadequate diets and the influence of non-refereed sources of information on their feeding decisions, a more proactive role by veterinarians in providing nutritional guidance to dog breeders may be necessary