Realistic prognosis for separation anxiety?

Question:
 I have recently been on the search for a rescue dog, and have found one that is absolutely everything I had in mind. I have had my application approved and have met the dog, and have definitely ‘fallen for him’. One of my plans is to do nursing home therapy, and he has got the ideal personality for it, he really is more than I could have asked for in a dog...there is just one issue, and that is separation anxiety.
My lifestyle will require a dog to be home alone for about four or five hours a day, which isn’t a big deal for a well adjusted dog but would be a big challenge for one with anxiety issues. I have done a lot of reading on it since I”ve been in contact with the foster mom about him (by searching for old posts on this site, and referencing several books including Patricia McConnell’s I’ll Be Home Soon: Preventing and Treating Separation Anxiety and Jodi Anderson’s “The Latchkey Dog .
Everything I’ve read has talked about gradually teaching the dog that it is NOT catastrophic to be alone, with desensitization exercises, etc. It sounds like a lot of work, which is NOT a problem for me, I’d be ready and willing to put time and effort into the issue. Over the summer my schedule will be flexible enough for gradual training.
My question is this: how realistic is it to think that a dog with major anxiety issues can be ‘rehabilitated’ to the point that he is unstressed while being alone for several hours?
>>What I’m really looking for in this post are experiences, both successes and ‘war stories’ about dealing with separation anxiety. I am in a dilemma because I am sincerely willing to put training effort into it, but I’m unsure of whether it is ‘treatable enough’ that I can reasonably expect the dog to be happy and comfortable after a period of time, or whether I should just decide that this foster isn’t the one for me.
Thanks for your time and sorry for the long post, but any and all advice/anecdotes/feedback is extremely appreciated.

Answer:
Hiyas GSDFan :)
My GSD was a rescue too. She had been through a few temporary homes after living in the streets, kennels, vets,and her foster home...and developed pretty extreme separation anxiety by the time we got her.
We worked with her and the first year the improvement was great. She could go 3-5 hours with no problem, loose in the house with two cat companions. She didn't like it, but she dealt with it. Then she got bloat... then breast cancer....hip replacement surgery...
All the vet visiting, stress, surgery, and us becoming rather neurotic parents pretty much undid all the work we achieved and she's pretty much back to square one now. I think _I_ developed separation anxiety just from having to watch her go through so much ! That isn't helping much at all, I must confess. Aging also plays a factor, as older dogs can suddenly develop SA or it can become more acute.
Realistically, if it is severe, it can be very difficult, but i think it is doable. We are waiting for her THR recover to be complete, and then it's back to the drawing board.
It is very very very hard to follow all the rules 100%, which you have to do if he has a severe case. Trainers and vets will blow you off and tell you to crate, do obedience, do this, do that, all while your dog is falling deeper and deeper into a routine of anxiety. A few tricks won't cut it. What we didn't do and I would now advice is getting a professional behavior therapist to evaluate the severity and type of anxiety he has, and work on it properly from day one. Some do better with crate training, some are traumatized by confinement, some by being alone or just away from a particular person etc etc. Some are afraid for themselves when away from the pack, some think YOU are in danger if you leave their presence. The more you know the better off you'll be in treating it. Some particulars are easier to treat than others, but most owners make the mistake of assuming all seperation anxiety is the same. The initial investment is worth it if it can save you some heartache. Dogs with SA are prone to hurting themselves and eating dangerous things. Obedience training does help too, of course, it's just not the cure all in this case. Those books you have read are great, and with the help of an experienced person, you'll have the upper hand in treating him.
Anna's particular details are that she is focused on one person, She does poorly when confined. If leashed, i can't get more than 5 feet from her without her starting to panic. If unleashed, we can take walks where she's a pretty far away, as long as she can see me and is not confined she doesn't seem to feel threatened or stressed. We suspect she's actually stressing over our safety, rather than herself.
She does best uncrated, but we have to be very careful because she will pull down blinds and eat anything she can to distract herself, so if for just a few hours, we usually crate her for her own safety.
She ignores food, toys, play , pain etc when having an attack. Her anxiety is extreme.
Even with all the painstaking sacrifices we've had to make and knowing now how emotionally trying it can be, I wouldn't trade her for anything. She is in an animal assistance therapy group called Delta. She is dying to please, loving, tolerant of everything. She has pretty high drive without being hyper or pushy, very easy to train. All her vets ask us if she is a service dog, because she is so patient as they pull and tug on her hips. The second we met her, after seeing 6 other dogs, we knew she was the one. The love just oozes out of her eyes. She's super focused on us, (which is part of the problem really) but that also makes her very responsive and trustworthy when we're out and about.
Things you might have to give up:
Vacations! Even if you take your dog with you, just going to a restaurant is stressful if you have to leave him in a hotel alone. We've become big fans of bed and breakfast places in the country, that let us take our dogs. Camping would be fun if the weather here wasn't so horrid.
Spontaneous all day adventures.
It gets old explaining to friends and family that you have to go home to your dog...no..not to feed or take out to potty..but because he's passed his 'alone' threshold. Ignore critical relatives :P.
If you are single, and suddenly start seeing someone, you can't really change your schedule and get wrapped up in new relationship tunnel vision.
So, to wrap it up... I suppose other question are will he be happier anywhere else? Will anyone else try as hard? Even if you can't succeed fully, can anyone else do better? Can you afford doggy day care if needed , or organize to exchange sitting with a friend/neighbor? It might help him to avoid extra anxiety while you work with him.
You've already done alot of research and reading, it seems. That alone seems to indicate you are up for the challenge.
Well, there's bits of pieces of my experience and opinion in the subject. Sorry I couldn't give you a more straighfoward,direct answer and I hope this helps a little, atleast. (i vote you adopt him! adopt him! ok, maybe i'm a bit biased)

Answer:
Thanks so much for the response, Stanna, you had a lot of great information in there for me (and it's always nice to meet a fellow GSD fan! :D ). I have been going back and forth in my mind on this issue and was really hoping for some feedback, I appreciate it. It is comforting to hear that the issues CAN be improved.
It sounds like this guy and your dog have a lot in common. Basically he's a "velcro dog" and gets extremely anxious when he's alone, to the point of destroying crates. The foster mom hasn't tried leavng him loose while along, because he also shreds/plucks blankets, toys, etc when alone and nervous. They have tried the stuffed kongs with him but from what I gathered it hasn't helped much. He does OK during the day while crated in the same room with the other dogs in the house, but gets panicked when left completely alone.
There are a couple of other dogs on my 'list' of rescues to look at, but this one seemed so perfect...it breaks me heart to think of passing him up, but then again it would break my heart even more to get him and find that he's miserable with me, you know?
Best of luck with your own dog, it sounds like she's had a lot to overcome lately! I hope she's recovering well and everything.
Again, insights/advice from anyone is greatly appreciated, I'm really torn on the issue.

Answer:
From my experience with my Shepherds - and the other dogs I've had - you won't be at peace unless you follow your heart.
German Shepherds also do better if they have something to take care of; a responsibility of their own when you're gone. It can be another dog (most GSDs are marvelous with small dogs especially), a cat, or sometimes even just assigning them to take care of the house.
Bimmer was a basket case when I'd have to leave him at home. He'd stand in the window and HOWL the until he heard me pull in the driveway. Once I told him it was his job to watch the house and take care of Gomez (the cat) while I was gone he calmed down. Whenever I leave the house the last thing I tell him - right after "I love you" - is take care of the house. Now, of course, he's got either Shiva or Kharma in the house with him so I tell him to try to keep the grrrrls out of trouble.
He looks at me like I've lost my mind and rolls his eyes . . .

Answer:
I think your prognosis is good. The most important things in working with any dog are consistency and the owner's willingness to devote time and effort to the dog. You're willing to work on it, which means you're already half way there. Separation anxiety can be tough to fix, but Patricia McConnell's book should tell you all you need to know. She's a wonderfully smart and talented trainer. It will take some work, yes, but I think you can do it.