There are so many options out there so finding a dog collar to stop barking for small dogs is not an issue. For example, you can go online and search for one. The Garmin Barklimiter 2VT anti bark collar has 3 stimulation modes to stop dog barking. They are Tone only, Vibration only and Smart mode (smartphone operated).
Source: https://www.dogmaster.com.au/bark-collars/small/
