Resumo:
Dogs are susceptible to metabolic changes resulted from an increase in total body adipose tissue, as consequence of high caloric intake. It is well established that the nutritional composition of the diet, as well as the choice of foods included, can influence the outcomes of a weight loss program. However, a caloric deficit remains the main strategy for reducing body fat. The hypothesis of this work is that caloric restriction based on the resting energy requirement can result in body weight loss similarly, regardless of the diet prescribed. However, it is expected that homemade diets and mixed feeding may improve the biochemical profile of dogs and the owner’s perception of integrated health, when compared with commercial dry food, mainly due to their greater flexibility in protein inclusion. Therefore, the aims of this study were to compare weight loss, hematological parameters, biochemical profile and behavior of overweight and obese dogs fed under caloric restriction using diets based on commercial dry food, homemade food, or mixed feeding. Animals of this study were domiciled, under owner care and the allocation of dogs into dietary groups was based on the owners' preferences, lifestyle compatibility and potential adherence to the diets, as assessed during the initial consultation and nutritional anamneses. A total of 34 dogs of different breeds were included in this study, with the following allocation: commercial dry food (n=9), mixed feeding (n=16), and homemade food (n=9). Each dog was monitored for approximately three months (104 days), with monthly consultations for clinical evaluation, caloric intake adjustments, blood collection, and morphometric measurements. In addition, behavioral and functional aspects were assessed through a questionnaire applied at each consultation. All diet groups achieved a similar body weight loss (4.5%) under caloric restriction, regardless of the diet type. Although most biochemical and hematological parameters showed no significant differences between diet groups, serum triglycerides were lower in homemade food group, even though this formulation presented higher fat content. Additionally, HDL concentrations increased over time regardless of diet type. These findings suggested that moderate caloric restriction can promote weight loss and influence lipid metabolism after 104 days in diet. Behavioral assessments based on owner questionnaires revealed differences among dietary groups in aspects such as physical disposition, social behavior, and food-seeking patterns. Dogs fed mixed diets showed higher frequencies of fatigue, difficulty running or climbing stairs, and reduced play at home. Most dogs were described as joyful and interested in walks, though the majority were considered only moderately active. Food-seeking behavior was more evident near or between meals but not excessive. Owners reported high adherence to the dietary plan, with low difficulty in avoiding treats and following the feeding routine. Overall, despite differences in behavioral patterns across diets, the average weight loss was not sufficient to promote marked functional or behavioral improvements.
