## 4 Discussion
It is essential to underscore that our study involved the analysis of only three batches of a particular product, recognizing the potential for variations among batches. However, despite this limitation, we assert that this report will serve as an impetus for manufacturers to enhance and rigorously monitor the nutritional value of both their raw materials and finished products, aiming to mitigate the occurrence of such discrepancies in the future. It is worth noting that our study, surprisingly, showed that the intended age of use for the dog food (puppy/adult) and the presence or absence of grains in the formuladid not highly differentiate these groups of foods from each other. Although puppyy foods contained, on average, more ether extract, crude fiber, crude ash, and energy than adult dog foods, and grain-free foods contained more crude protein and energy than grain-included dog foods (Table 1), [PERSON]'s similarity analysis (Table 2) revealed a large number of similarity coefficients between these groups of foods, indicating the limited validity of such divisions in the analyzed set of canned dog foods. This confirms other studies on cat foods in which the inclusion or exclusion of cereals in the formulation and the categorization of foods by life stage did not significantly impact the crude protein content of the pet foods [60]. However, it is essential to note that this does not imply interchangeability between puppy and adult dog food. Our study only analyzed basic nutrients (macronutrients), and variations in individual amino acids, minerals, and fatty acids, specific to each age category, were not considered. These parameters, unexplored in this study, can significantly influence product differentiation. Additionally, although not conclusively demonstrated in our study, the presence or absence of grains can indeed influence the nutritional value of the final product, as suggested by earlier research [61; 62]. In our previous investigation [62], the addition of grains to dog food notably impacted the quantity of carbohydrates in the diet, concurrently reducing the average contents of protein, fat, and ash. The grain-free trend in the pet food sector has gained substantial attention [63], underscoring the significance of taking these factors into account when choosing dog food. Pet food is subjected to strict regulations to ensure the highest standards of hygiene, safety, and quality. European pet food manufacturers are obligated to comply with a series of regulations that cover the entire production process, from the selection of raw materials to the sale of the final products [33]. However, there is a lack of strict regulations regarding the maximum limits for individual biological contaminants in pet food. Under EU regulations, it is stipulated that \"the feed business is primarily responsible for feed safety\" [64]. Nevertheless, numerous publications have highlighted concerns related to the quality and safety of pet food [65; 21]. In recent years, the most attention in scientific research on commercial pet foods has been focused on the relatively new raw dog and cat foods in the market (raw-meat-based diets, RMBDs). On the one hand, they have gained popularity among pet caregivers seeking a more natural feeding option than conventional, processed pet food. On the other hand, these products have raised significant concerns about their microbiological quality and safety. These diets remain unprocessed, making them susceptible to pathogenic bacterial contamination, which can pose significant risks to pets' health. Numerous studies have reported the adverse consequences of feeding RMBDs to dogs, including bacterial diseases, parasitic diseases, and nutrient imbalances [19; 66; 67; 68; 69; 70; 71; 72]. The microbiological quality of canned dog foods is less frequently addressed in scientific research. Canned pet foods undergo a heat treatment process to attain commercial sterility, effectively removing heat-sensitive pathogens. Consequently, they are generally considered to be safe and reliable products.