how to deal with seperation anxiety with dogs?

Question
I have a 31/2 year old boxer terrier mix and every time i leave her in her crate she poops in it.  I have had her since March and it use to be a lot worse but she still does it off and on.  We got her from the shelter and they couldn't really give me a history on her.  She is really a great dog when we are home but when We leave her she would destroy things and poop if she was left in the house and she poops in her cage almost everyday?  Can you please give me any help or suggestions that you have thanks.

Answer
Hi Kelly,

Some possibilities/solutions:

She may have come from a pet store.

Try moving the crate to a different room and give her something really high value (like a raw, frozen marrow bone) when you leave her. Also, put her in it sometimes when you are home so it's not exclusive to when you leave.

If you free feed-control the meals.

Deworm her. More common than you would think!

Comfort zone plug in.

A couple of good books:
Dogs Home Alone-Abrantes
I'll be home soon-McConnell