I saw a thread about using shock collars and I'm not sure if it was discussed (didn't see anything). But for those of you that wanted to try the shock collar but are afraid to, there are other methods. My miniature pinscher barks constantly and I live in an apartment. I would never use a shock collar on her, no matter how small it it, I tried the sonic ones and she didn't even flinch. The best one i found is called Gentle Spray. It's a little box filled with citronella so when she barks it sprays a little mist that startles her. Since is works on all her senses (see it, hear it, smell it, feel it and probably taste it too) it's more effective and much more humane. Hopes this helps