Separation Anxiety

Question
We have a 9-year-old yellow female lab.  Whenever we leave the house, even for a few minutes to go the neighbors, Bailey starts to howl a heartbreaking howl.  This can go on, as we are told by neighbors, for the entire duration we are gone.  She is left inside the house with our two cats and two rats.

We have purchased a antibarking collar but haven't had the heart to put it on her.

Any suggestions to break this problem?  She's a great dog, eager to please, very trainable, loves people, I could go on and on.  I imagine this to be one of the toughest problems to fix, especially at her age.

We rarely leave her alone more than a few hours.  I'm stay-at-home mom who also works at home, I take her with me when I can so she's not alone that much.  

Can you help her?

Answer
At 9 years old, this may be beyond me, or others.  You could try the old peanut butter in the Kong trick.  Works well on younger, highly food motivated Labs.  She may be highly food motivated, but I am afraid she will continue her ways, perhaps working on it until the door close, then back to her howling.  Still, if you don't have a Kong, you can pick one up at almost any pet store for about $10.  If it works, even partly, there are some other things including the Buster Cube.  You put kibble in a small hole, and the dog rolls it around an pieces fall out once in a while.  The Labs I have seen give up rolling it around and chew it.  If it and her survive, she can't howl while she is chewing.  Don't leave her long the first time, and forget it if she damages it. The pieces could choke her.