Huh, the same slogan is used in concession states in China during that period too. "Chinese and dogs not permitted entry/华人与狗不得入内". It is still taught in text books and a great historical wrong to the chinese ppl, I guess it's a trendy slogan, never thought it's also used in other places.
Though there are indeed many historical similarities between the poles and the chinese in recent history, here's to the first and second greatest economic miracles after WW2, Polska Górą!