Using a cross-sectional study design, the prevalence of overweight and obesity in dogs over 1 year of age seen by US veterinarians during 1995 was determined. Risk factors for overweight and obesity were also determined from the following variables: age, breed, gender, body condition score, food type, reported concurrent disease, and geographic region. Thirty-four percent of adult dogs (n = 21,754) were overweight or obese. From multivariate analyses, overweight dogs were more likely to be older, of certain breeds (Cocker Spaniel, Labrador Retriever, Dalmatian, Dachshund, Rottweiler, Golden Retriever, Shetland Sheepdog, Mixed-breed), neutered, and to consume a semi-moist food as their major diet source. In addition, overweight adult dogs were most likely to reside in the