Yeast-purified beta-1,3/1,6-glucans (BG) can modulate dogs’ immune systems and microbiome, but the optimal inclusion dose remains unknown. The aim of the study was to evaluate the effects of 0.0, 0.07, 0.14, and 0.28% inclusion of BG in a dry extruded diet on the digestibility, immunity, and fecal microbiota of healthy adult dogs. Eight male and female border collies [n = 4; body condition score (BCS) = 5] and English cocker spaniels (n = 4; BCS = 5), aged 3.5 ± 0.5 years, were randomly distributed into two 4 × 4 balanced Latin squares. Fecal microbiota (using 16S rRNA sequencing, Illumina^®), apparent digestibility coefficients (ADC) of nutrients, fecal concentrations of short-chain fatty acids (SCFA) and branched-chain fatty acids (BCFA), ammoniacal nitrogen, lactic acid, IgA and pH, lymphocyte immunophenotyping, intensity and percentage of phagocytosis and oxidative burst were determined. No differences were observed in Faith (p = 0.1414) and Pielou-evenness (p = 0.1151) between treatments, but beta diversity was different between 0.0% and 0.14% BG groups (p = 0.047). Moreover, the Firmicutes phylum was the most abundant in all groups and exhibited the highest relative abundance after the consumption of 0.14% BG, a finding considered beneficial for the canine microbiome. The Erysipelotrichaceae and Ruminococcaceae families, along with the Faecalibacterium and Prevotella genera, considered favorable for their involvement in butyrate production and other metabolites, showed increased abundance after the consumption of 0.14% BG. The potentially pathogenic Proteobacteria phylum displayed lower abundance after the consumption of 0.14% BG. Fecal concentrations of the evaluated compounds and pH did not differ after consumption of the BG at all percentages. Higher crude protein ADC was found after 0.14 and 0.28% BG consumption (p < 0.0001), but no differences were found for other nutrients. Phagocytosis, oxidative burst, and lymphocyte populations were not modulated by any of the treatments; however, 0.14% BG modulated the lymphocyte T CD4⁺:CD8⁺ ratio (p = 0.0368), an important marker of immune system efficiency. The inclusion of 0.14% BG resulted in the best responses and was the best dose evaluated.

Food allergy triggers an immune response to dietary proteins, resulting in food rejection and dermatological and gastrointestinal manifestations. The preferred therapies include diets with hydrolyzed proteins or unusual single-source proteins, with insect protein emerging as a promising option, with no reported allergic reactions in dogs with a food allergy. In this case study, the effects of including black soldier fly larva (BSFL) meal were observed in a 5-year-old spayed beagle previously diagnosed with a food allergy. The objective was to assess the potential of BSFL meal as an adjunct in treating a food allergy. As part of the protocol, two nutritionally very similar diets were used, differing only in the protein source: the control diet, with poultry by-product meal; and the BSFL diet, which completely replaced the poultry by-product meal. After a 12-day adaptation period to the BSFL diet, the dog showed no gastrointestinal changes, maintaining an adequate fecal score and no clinical signs of the disease. A challenge test with the control diet resulted in episodic gastrointestinal symptoms, which were reversed within two days by reintroducing the BSFL diet. The BSFL protein-based diet was effective in controlling the dog’s clinical signs.

In small animal nutrition, the caloric content of a diet is expressed as metabolizable energy (ME). The gold standard method for determining this variable is through feeding trials with the target species. However, the high cost and intricacy of this assay lead to the use of indirect estimation methods. The aim of this study was to analyze the main equations employed for estimating ME and compare them with the results of in vivo tests. In total, 451 pet food products in Brazil were evaluated. The ME values were determined via the bromatological values available on labels. The data were analyzed using SAS, and Student’s t test was used with a significance of 5%. For all predictive equations, there was a non-conformity between their results and those obtained by in vivo methods. Thus, the prediction equations are only accurate when the exact values of food composition are used, which is hardly applicable since veterinarians and animal owners only have access to the information provided on the labels. Nonetheless, the Atwater system equation proved to be the most reliable for estimating ME, showing the smallest disparity among the evaluated methods. The overall differences between in vivo results and ME estimation with the Atwater system amounted to 3.59% for dry cat foods and −1.94% for dry dog foods. Moreover, although it was also the most accurate for wet foods, the differences were substantially greater (11.99% for cat foods and 8.25% for dog foods). These findings highlight the need for further research to refine ME estimation, which could contribute to improved pet food formulation and help reduce cases of malnutrition in dogs and cats.

Accurate estimation of metabolizable energy requirements (MER) is essential for appropriate dietary planning in dogs. However, standardized recommendations may not reflect the variability observed in clinical practice, particularly regarding individual factors such as neutering status, body condition, and age. This study aimed to retrospectively assess the MER factor in dogs treated at a Brazilian veterinary hospital, considering variables including sex, neuter status, body condition score (BCS), muscle mass score (MMS), body size, and life stage, and to compare the findings with those typically reported in the scientific literature. A total of 438 medical records from 2013 to 2025 were reviewed for this study. Data on demographic and clinical variables were collected, and MER factors were calculated based on energy intake and body weight. Statistical analyses were conducted to evaluate the interactions between variables, particularly BCS and neutering status. The study population included 253 males (57.8%) and 185 females (42.2%), with 80.6% of them being neutered. The MER values varied widely across the subgroups. Neutered dogs had consistently lower energy factors than intact dogs (p < 0.0001), and energy requirements decreased progressively with increasing BCS, regardless of neutering status (p < 0.05). A significant interaction between BCS and neutering status was observed (p = 0.0089), although BCS alone was not a significant predictor (p = 0.9670). No substantial differences were observed based on sex, body size, or life stage. MER values observed in clinical practice differ from standard recommendations and are influenced by the interaction between neutering status and body condition. These findings reinforce the need for individualized nutritional assessments in companion animal medicine and call for further studies to refine clinical energy estimation models.

Metabolomics has proven to be an effective tool for elucidating mechanisms and assessing the effectiveness of dietary interventions in canine and feline nutrition. In this context, the present study aimed to perform a metabolomic analysis of the serum of dogs supplemented with increasing levels of beta-1,3/1,6-glucans to generate evidence and gain a deeper understanding of the metabolic responses associated with this supplementation. Eight dogs were evenly assigned to two balanced 4 × 4 Latin squares. Four diets were tested, differing only in beta-glucan content (0.0%, 0.07%, 0.14%, and 0.28%), and the dogs were fed according to their individual maintenance energy requirements. Each experimental period lasted 35 days. On day 35, 5 mL of blood was collected via jugular venipuncture to obtain serum for metabolomic analysis. Nuclear magnetic resonance analysis identified 12 key serum metabolites. Hierarchical heat map analysis revealed differences in metabolite intensity between treatments (p < 0.05). Additionally, the most relevant metabolic pathways were phenylalanine, tyrosine, and tryptophan metabolism; alanine, aspartate, and glutamate metabolism; and glyoxylate and dicarboxylate metabolism. This study demonstrated that increasing levels of purified beta-1,3/1,6-glucans from Saccharomyces cerevisiae modulated key metabolic pathways in dogs, particularly those related to amino acid, lipid and energy metabolisms, and gut microbiota. These findings provide insights into the mechanisms by which beta-glucans influence canine health.

The World Small Animal Veterinary Association (WSAVA) and the American Animal Hospital Association (AAHA) recommend that treats make up no more than 10% of daily energy intake for dogs and cats. This study assessed whether replacing 10% of maintenance energy requirements with commercial treats affects the nutritional adequacy of diets. Labels from 226 dry extruded diets for adult dogs and 124 for adult cats in the Brazilian market were analyzed, along with 170 dog treats and 114 cat treats (dry, wet, or liquid). Maintenance energy requirement calculations followed FEDIAF (2024) guidelines. All diets for active and inactive dogs met protein and fat requirements after a 10% intake reduction and the inclusion of any type of snacks. Regarding protein intake, all diets met the minimum requirement for active cats. However, for inactive cats, some diets failed to provide enough crude protein after restriction (36.29% of diets with dry snacks, 16.12% with wet snacks, and 2.41% with liquid snacks). Concerning fat content, only 1.61% of diets failed to meet the minimum when liquid snacks were included. On the other hand, when considering the equation and the needs of inactive cats, 29.03% of diets with dry snacks, 28.22% with wet snacks, and 44.77% with liquid snacks did not meet the minimum. Reducing food intake to accommodate treats may not be ideal, depending on diet composition and treat selection, particularly for neutered and indoor cats.