Soybean meal and poultry offal meal are protein ingredients commonly used in the formulation of commercial diets for dogs. However, there remains great variability in the data on the digestibility of each protein source. This systematic review study aimed to examine the intake, apparent nutrient digestibility coefficients and fecal output of protein sources (soybean meal and poultry offal meal) in adult dog food as reported in published studies. The article search was conducted in August 2018 in the PUBMED, SciELO, Science Direct and AGRIS indexing databases. The literature search was performed using "digestibility", "source protein" and "dog" as the main key terms combined with sub-terms to broaden the scope of the search. Criteria were defined for readability, exclusion and inclusion of articles. Results were organized in groups according to the search in the indexing databases, totaling 1,414 articles. After the works were selected following the inclusion criteria, 17 articles were evaluated in this review. According to most studies, plant-based ingredients have a less variable nutritional composition than animal-derived ingredients and poultry offal meal increases the digestibility coefficients of nutrients and energy and reduces fecal dry matter production. Factors inherent to raw-material origin, ingredient and food processing, as well as the high heterogeneity of the methodologies evaluated in the studies are directly related to the obtained results. To ensure a more accurate evaluation of the quality and of effects on the digestibility of protein sources, we recommended that articles include ingredient processing data and that the variables be evaluated under standardized study conditions.

Canine obesity is a complex, multifactorial condition marked by excessive body fat accumulation due to a sustained positive energy balance. Over the past decade, its global prevalence has risen significantly in most industrialized nations. Despite the availability of numerous commercial diets designed for obesity management in dogs, these products exhibit considerable variability in nutrient composition, and there is currently no standardized guideline on optimal macronutrient levels for effective weight loss. This study aimed to evaluate the effects of specific macronutrient levels on weight loss and body composition in obese dogs. A comprehensive literature search was conducted from 2022 to 2024 across PUBMED, Scielo, Web of Science, and Google Scholar. Out of an initial 1727 documents, 20 studies met the inclusion criteria and were incorporated into this meta-analysis. Diets with energy densities below 3.275 kcal, protein levels above 25%, total dietary fiber exceeding 12%, lower fat (<10%), and reduced non-nitrogenous extract (<40%) demonstrated beneficial effects on all evaluated parameters, including weight loss and body composition assessment. This meta-analysis provides evidence-based nutritional recommendations on optimal caloric, protein, fiber, fat, and carbohydrate levels for hypocaloric diet formulations, supporting healthy weight loss and lean mass preservation in obese dogs. These findings contribute to the development of effective dietary strategies that enhance canine quality of life and longevity.

O presente trabalho teve como objetivo comparar os efeitos da substituição da polpa de beterraba por níveis crescentes do farelo de arroz na digestibilidade da dieta, nas características fecais e na preferência alimentar de cães adultos. Foram utilizados oito cães adultos da raça Beagle, distribuídos em quadrado latino duplo (4 x 4). Os animais foram alimentados com quatro dietas distintas: controle (0% de inclusão de fonte de fibra), 5% polpa de beterraba (PO), 5% farelo de arroz (5% FA) e 10% farelo de arroz (10% FA). A digestibilidade da matéria seca (MS) das dietas controle e PO foram superiores as dietas contendo 5% FA e 10% FA (P<0,05). Da mesma forma, a dieta com PO apresentou maior digestibilidade da proteína bruta (PB) comparando-se com o grupo controle e com os grupos FA (P<0,05). Por outro lado, ambos os grupos FA (5% e 10%) apresentaram maiores níveis de energia metabolizável (EM), comparado com a dieta contendo PO (P<0,05). Com relação as características fecais, a concentração de amônia, a matéria seca (MSf) e o pH fecal do grupo 5% PO foram inferiores aos grupos controle e os grupos contendo FA (5% e 10%) (P0,05). No ensaio de preferência alimentar a razão de ingestão foi superior para a dieta contendo 10% FA (P<0,05). A inclusão de até 10% de FA, em substituição a PO, reduz a digestibilidade da MS e PB, mas, em contrapartida, eleva o teor da MSf, sem alterar o consumo alimentar e a produção de ácido siálico fecal dos cães.