Determination of macro elements and in vitro phosphorus solubility in cat diets produced in Türkiye

Although pet owners have access to a wide variety of cat feed options, there are significant concerns regarding the extent to which these feeds meet the nutrient levels recommended by relevant institutions and regulations. The health of domestic animals is also dependent on the adequacy of the nutrients contained in their feed. While the life expectancy of house cats is increasing, various studies have shown that the leading cause of death in cats over five years old is kidney disease. The relationship between inorganic phosphorus additives and kidney diseases has also become a focal point of academic interest in recent years. For these reasons, the aim of the present study was firstly to determine to what extent the cat foods produced in our country meet the nutrients including macrominerals, recommended by the relevant institutions and regulations. In addition, to determine the in vitro phosphorus solubility of these foods and to evaluate all the results obtained in terms of kidney disease risk. Fort this purpose, various brands of premium/economic adult-kitten dry feeds produced in Turkey, feeds produced with freeze-dried technology, and special feeds for kidney disease were collected from pet shops and veterinary clinics. The collected cat foods were first evaluated for compliance with AAFCO and FEDIAF guidelines by nutrient analysis with Weende System and macromineral analysis with ICP-MS, and then they were subjected to phosphorus solubility analysis. Of the 38 feeds analyzed, only one (2.6%) met the minimum crude protein, crude fat, and macro-mineral levels recommended by both AAFCO and FEDIAF. According to the guidelines of these institutions, among the feeds produced in our country: 10 out of 15 premium feeds lacked crude protein, 1 phosphorus, and 13 potassium, while 14 out of 15 economic feeds lacked crude protein, 1 calcium, and 9 potassium. As expected, in vitro phosphorus solubility rates were lowest in feeds formulated for kidney disease. Both premium and economic kitten and adult cat feeds produced in our country were found to be similar in terms of containing water-soluble phosphorus sources known to be nephrotoxic. This result suggests that the naming policy of feeds according to raw material quality may be misleading.