My friend has a working cocker spaniel, she has one of these, stops her from pulling on the lead, he advised me to get one as Callie pulls a lot, so I bought one today, Callie hates it, took her out on it this afternoon, she was pawing it , turning somersaults, lying down in the road, she looked so distressed!........don't think I can persevere with this, she was so distressed by it!........what do you think?.............