We use harness for walking ,due to their short necks and breathing im to afraid i do some damage rather than good so we only use collar to keep Lillys tag on
We do the same as Pati. We only use the collar for her tags and she wears a harness when we go on walks. However, when it is raining out i will put he on a leash connected to her collar as a means to keep her from the puddles but that is the only time and it is usually less than 5 minutes.