I adopted a shitzu, lopsa apsa mix (i know I didn't spell those right)  from a rescue back in December.  He is a year old.  I cannot, I repeat, cannot get him to stop urinating and pooping in the house!  He is very submissive and I think it is because he was abused, so he naturally does the "scared pees" when he gets frightened, but other than that, I will leave the back door open for him to go outside with our other dog, and he will come in to pee in the house?  I don't know what to do.  He is spending the days in a crate and alot of time outside.  I can never catch him in the act, so it is hard for me to properly train him?  I read somewhere that alot of rescue dogs will never be housetrained?  Is this true and does anyone have any advise?  Please help.  I would love for him to spend more time with the family and snuggling at night instead of being in his crate.