Food Preferences in Dogs: Effect of Dietary Composition and Intrinsic Variables on Diet Selection

A ten-year food preference database (2007-2017) was used to relate food selection in dogs to the nutritional components of diets by doing a principal component analysis (PCA) and a linear regression between components obtained and dogs' preferences. Intake and preference of preferred diets were analyzed by dogs' sex, breed, age, body weight, and the season of the year (hot or cold). The fourth component after PCA presented a relation with food preferences (OR = -2.699, p = 0.026), showing negative correlations with crude fiber (rho = -0.196; P = 0.038) and dry matter (rho = -0.184; p = 0.049). Weight (OR = -1.35; p < 0.001), breed, both Boxer (OR = 10.62; p = 0.003) and Labrador Retriever (OR = 26.30; p < 0.001), and season (hot season) (OR = -5.27; p < 0.001) all influenced animals' intake. Boxers presented a lower food preference compared to the other breeds (OR = -44.3; p < 0.001), while animals' weight influenced preferences only in Boxers (OR = 2.02; p < 0.001). Finally, age and sex did not affect dogs' preference or intake of preferred diets. Thus dry matter and fiber content have a negative impact on dogs' food choices. Dogs' weight, breed, and season affected food intake, but only breed affected dogs' preferences, which is probably explained by adaptive changes in the detection, metabolization, and learning of nutritive food cues.