But "que han dejado tus perros" means "that have left your dogs" with a stylish order change (the real meaning is "that your dogs have left").......but as a matter of fact even people might fail at understanding that.
If you wanted to clarify that the dogs were left (not the caca), then you can add 'a' to indicate the object, as in "...que han dejado a tus perros."
(not sure about "caca", though).
Caca is correctly translated as 'shit' (though swear words vary depending on the country. We do this in English too: bloody and shag are not swear words in America, but are in England).