This study aimed to investigate the effects of dietary Ptecticus tenebrifer on the fecal microbiomes of bichon frise. A total of 16 bichon frise dogs (average weight, 2 kg) were randomly allotted to 4 dietary treatments (4 dogs/group): general pet food, two types of domestic pet food containing Ptecticus tenebrifer, and one imported pet food containing Ptecticus tenebrifer. In the controls, Firmicutes accounted for the highest proportion (82%) at the phylum level in the fecal microbiomes. The Tax4Fun2's functional prediction program indicated that the control groups showed a relatively high amount of obesity-related microorganisms; the pathways included three types of carbohydrate metabolism. Among the treatments, Firmicutes abundances was the least in the treatments with the two types of domestic pet food containing Ptecticus tenebrifer; this did not affect the functional prediction of Tax4Fun2. In conclusion, the two types of domestic feed with Ptecticus tenebrifer were healthy and suitable for bichon frise; they could be beneficial in terms of obesity.