Citronella bark collars are available for any sized dogs, especially the little ones. Many of these collars are adjustable and this essentially means that the regardless of the size of your pooch, there will be a collar that they will be able to use. This is good news for people who are tired of dogs barking too much and want to take things into their own hands. The collar essentially works by spraying out citronella, which dogs do not like. From there anytime they bark, they will be sprayed with this spray that they are not too fond of. This is an excellent tool is the barking from the small dog has gotten to become too much.