Background and Aim:This study examined the impact of dietary fortification with rosemary (Rosmarinus officinalis) and/or basil (Ocimum basilicum) leaves powder on glycemic status of dogs.Materials and Methods:Forty-five Rottweiler dogs were assigned to five experimental groups and fed an experimentally processed extruded basal diet that was either fortified or not fortified. G1 was fed the basal diet without any fortification (negative control); G2 was consumed the basal diet supplemented with a commercially available synthetic palatant (positive control); G3 was provided with rosemary fortified (at 0.05%) basal diet; G4 was provided with a basil fortified (at 0.05%) basal diet; and G5 was offered a rosemary and basil fortified (each at 0.025%) basal diet.Results:G4 and G5 exhibited a positive impact on growth performance traits. Dogs in G3, G4, and G5 showed significant decreases in serum glucose levels in comparison to dogs of the control groups (G1 and G2). It was clear that the inclusion level of 0.05% of basil leaves powder showed the greatest hypoglycemic action. Indeed, G4 dogs showed a reduction in blood glucose at a percentage of approximately 31% followed by G5 and G3 groups (16.25% and 14%, respectively). Furthermore, basil leaves inhibited the amylase enzyme activity. Both insulin and cortisol levels in G4 dogs were increased and reduced compared to controls, respectively. In addition, dietary fortification with rosemary and/or basil significantly increased glutathione, superoxide dismutase, and catalase levels, while values for malondialdehyde and lactate dehydrogenase were decreased.Conclusion:It could be concluded that dietary fortification of dog diet with rosemary and/or basil leaves powder at 0.05% separately or 0.025% in combination might be used as promising modulators of blood glucose levels as well as clinico-nutritional management tools for the prevention and control of diabetes mellitus in dogs.