Valutazione della qualità del pet food e analisi del microbiota intestinale in cani con differente condizione corporea

A complete and balanced diet is essential to maintain animals in good health. Most dogs and cats in Europe, the United States and other developed countries are fed commercially manufactured pet foods, whose market is still growing every year. Commercial pet diets should provide safe and nutritionally balanced foods to meet the animal's nutritional needs; therefore, pet food manufacturers are required to follow the recommended allowances presented by the European Pet Food Industry Federation. European feed law also establishes rules and requirements for labelling to provide adequate information for consumers. At the same time, we are seeing an increasing popularity of commercial raw pet food diets, as many owners choose to feed a more natural or ancestral diet to their pets due to anecdotal health benefits. However, since pet food labels lack precise information and there is a scarcity of regular controls, concerns may arise about the quality of commercially available pet diets, both extruded and raw. The overall aim of this project was therefore to provide greater insight into the nutrient composition of commercial pet food and the microbiological quality of raw meat-based products. First, a general introduction about pet foods' features and sales is provided in Chapter 1. Chapter 2 explores the amino acid composition of 80 complete pet foods. Dietary proteins should provide all the essential amino acids that animals cannot synthesize, and whether the intake is sufficient to meet their requirement, depends on the protein quality included. The amino acid composition of the selected pet food showed limited variability among different categories, and some products displayed certain essential amino acids deficiency. Chapter 3 is centered on the fatty acid profile of 22 complete and 21 complementary pet foods. Fat is an important component of pet food which provides essential fatty acids and improves the palatability. Moreover, specific omega-3&6 supplements are formulated to improve the pet's health in certain disease conditions. The lipid composition of the analyzed products showed great variability, mainly depending on the ingredients included, and unacceptable discordances were found among labeled and analyzed values. 5 The aim of the study reported in Chapter 4 was to shed light upon the problem of contamination in novel protein diets and hydrolyzed protein diets testing for the presence of 19 animal species. Elimination diets are common tools for the diagnosis of adverse food reaction in dogs and cats, but the presence of undeclared ingredients may negatively interfere with the trial and prevent the veterinarian from making an appropriate diagnosis. Of the 40 analyzed products, only ten presented a content that correctly matched the label. In Chapter 5 the evaluation of the microbiological quality of raw-meat pet foods purchased online is reported. It has been well documented that feeding raw diets increases exposure to dangerous bacteria for both pets and humans, raising questions about the quality of raw meat-based products intended for dogs and cats. The collected products were largely contaminated by microbes and more than half of the samples resulted positive for potentially zoonotic bacteria. Finally, the last chapter of this PhD thesis deals with the gut microbiota instead. Previous work has shown obesity to be associated with changes in intestinal microbiota; however, while obesity has become a health epidemic in pets, limited information is available about the role of the canine gut microbiota. The aim of the study described in Chapter 6 was to investigate whether alterations in the intestinal microbiota may be associated with canine obesity. Using 16S rRNA gene sequencing, the composition of the fecal microbiota in 15 lean and 14 overweight pet dogs was evaluated. The gut microbiota of the recruited dogs showed considerable interindividual variation, but no significant differences based on body condition.