Development of a Preference Ranking Test with Dogs

One of the key drivers pet owners use to select the ideal food for their companion animal is liking. However, there is a scarcity of tests to quantify liking. Therefore, the objective of this study was to develop a test that might provide insight into liking. The underlying hypothesis was that dogs would work to solve a puzzle for foods they liked. Twelve Beagle dogs were presented with a puzzle-test to determine the multi-choice ranking of various treats. Each dog was presented with five options to which a different flavor and (or) aroma compound had been applied to baked treats prepared in our laboratory. The treats were placed inside a numbered rubber puzzle toy (Kong®), from which the dog had to extract the treat before consuming it. Once chosen the puzzle toy was removed with four choices remaining, then three, two, and a final choice. Each of the five phases lasted 5 days. The phases included: (1) an adaptation or learning period, (2-4) ingredients tests: (2) fats: fish oil, butter, vegetable shortening, chicken fat and lard, (3) proteins: liver, chicken, fish, tofu, and beef, and (4) starches: corn, wheat, tapioca, potato, chickpea. Phase 5 tested commercial foods that were labeled as “Fish and Potato” (F/P), “Chicken and Rice” (C/R), “Lamb and Oatmeal” (L/O), “Turkey and Chickpea” (T/C), and “Chicken and Pea” (C/P). The order of selection and extraction was recorded and the data were analyzed accordingly as a Friedman analysis of variance. The dogs ranked fish oil and butter above (P<0.05) lard, with vegetable shortening and chicken fat intermediate. Chicken liver was ranked higher (P<0.05) than beef, with chicken, fish, and tofu intermediate. Corn was ranked higher (P<0.05) than tapioca, potato, and chickpea with wheat intermediate. The F/P was ranked higher than all other treatments. The study confirmed the hypothesis that dogs will work for foods they like. This test provides insight into methods for understanding dog liking when presented with options.