Yes, you can use a no bark collar on small breeds of dogs even on puppies provided you choose the right size of the collar. A snug-fitting collar is best rather than a loose-fitting one. That being said, it is also critical to consider the weight of the device. Since these need to be worn by your pet around its neck it is crucial that they not be so heavy so as to cause strain on the cervical spine of your pet dog. The size of the collar and the weight of the device has to be taken into consideration when using this on a small breed of dog.