The Rubber Dumbbell is a toy that appears in Nintendogs + Cats. It works much like a Soft Cube as when thrown dogs chase after it to bite. It can be obtained from the Mr. Recycle shop. This is a dog toy and cats will ignore it. It is rumored that playing with this toy will make them faster.
3DS US: "This toy isn't for working out, but it's great for chewing!"
3DS UK: "This toy isn't for exercising, but it's great for chewing!"
- Rubber x2