Elemental composition in commercial dry extruded and moist canned dog food

The aim of the study was to investigate elemental contents in commercial pet foods for adult dogs at maintenance. The elemental composition of 15 dry extruded diets (DED) and 22 moist canned diets (MCD) collected from a pet shop were analyzed in triplicate with inductively coupled plasma optical emission spectroscopy and with mass spectrometry for Se. Significantly higher contents of Ca, P, (P < 0.05), K and Na (P < 0.0001) were measured in MCD than in DED, whilst the contrary was observed for Cu and Zn (P = 0.001). All the analyzed foods supplied on average micro minerals above the recommended daily requirements of FEDIAF, except for Cu (mean supply of foods 85%+12) in the MCD and Se both in DED (mean supply in foods 21%+4) and MCD (mean supply in foods 34%+7) samples. All the analyzed foods supplied macro elements above the recommended daily allowances except for K (73%+6) in the DED and Mg (92%+5) in MCD. Principal component analysis with essential elements (EE) as input variables (Ca, P, K, Na, Mg, Fe, Mn, Zn, Cu, Se) explained 63.85% of total variance with the first two components and clustered DED and MCD. Factor scores of Cu, Zn, Mg and Mn were higher for MCD and Ca, P, K and Na for DED. Significantly higher (P < 0.01) frequency of presence of non essential elements (NEE) Cd, Cr, Li and Pb (p < 0.01) were observed in MCD in comparison to DED. Although there are limitations in this study, the results showed a wide variability of elemental contents among per foods and suggest the need of routinely analysis to accomplish with the recommended daily allowances and for the s