I have taken in my friend's pomeranian and he used to poop on the wee wee pad which was great. But we notice that whenever we are home now, he would poop near us or even in the hallway and then start shaking next to us. When no one is home or when I am out running, he would poop on the wee wee pad. Is this a behaviour problem? My wee wee pad is always clean as I have 2 other pooches of my own so I always change wee wee pads.