To provide a toothbrush for a dog, allowing the inside surface, the outside surface and the top part of a molar to be simultaneously brushed without turning the hand holding the toothbrush in the right and left directions.

The toothbrush 10 for the dog has a brush part 12 planted on the tip part of a toothbrush body 11, and a holding part 13 formed at a base part. The brush part 12 has brush hairs at least in three lines along the longitudinal direction of the toothbrush body 11. The brush hairs 14 at both the sides contact with the inside surface and the outside surface of the molar of the dog respectively, and the center brush hairs contact with the top part of the molar to enable them to be brushed simultaneously. The tips 14a of the brush hairs 14 at both the sides are bent in the direction getting near to each other.