Quantification of vitamin D3 in commercial dog foods and comparison with Association of American Feed Control Officials recommendations and manufacturer-reported concentrations

OBJECTIVE To quantify vitamin D3 (VitD3) concentrations in commercial dog foods and compare those concentrations with Association of American Feed Control Officials (AAFCO) recommendations and manufacturer-reported concentrations. DESIGN Cross-sectional study. SAMPLE 82 commercial dog foods. PROCEDURES Samples of commercially available dog foods were obtained from owners of healthy dogs in the Guelph, ON, Canada, area and owners of dogs that were patients at the Ontario Veterinary College Health Sciences Centre's Mona Campbell Centre for Animal Cancer. For each food, the VitD3 concentration was determined by high-performance liquid chromatography–tandem mass spectrometry, and adherence to AAFCO and National Research Council recommendations was assessed. Analyzed VitD3 concentrations were compared with manufacturer-reported VitD3 concentrations and between wet and dry foods, among AAFCO nutritional adequacy statements (nutrient profiles vs feeding trials and adult maintenance vs all life stages), between f...