Maybe a bellyband, if he still has accidents would be a safer alternative. Neutering may help some. Also, restrict his freedom in the house until he's fully trained. One room lined with peepads, or an ex-pen. Very glad your Mom agreed to reevaluating her methods. Also, explain that Yorkies are really a different breed and learn only through positive reinforcement. They really don't get any negative reaction, just develope fear about it.
Also, use an enzematic cleaner on the accidents so he won't resoil, like Nature's Miracle. |