Underweight, seemingly starving GSD

The NB looks MUCH better.  The second ingredient is duck meal, which is the duck with the bones and water removed...basically CONCENTRATED duck, then followed by duck, where the RC is duck by product meal and the duck itself is hiding way down there.

The only hesitation I would have is that the Natural Balance has been "caught out" by he big recent recall and never gave a suitable explanation for how a grain protein got in their feed, nor any assurance on how it would be prevented in the future, in spite of many requests from both official figures and private folks for this information.  The IVD/RC has remained "clean".  I don't trust NB anymore, especially for use with a sensitive dog.

 And also, NB has flaxseed, which is a big allergy triggor for a LOT of dogs.

Also, the RC food is made in a dedicated plant. No gluten EVER enters that plant, and no chicken or any sort of grain enters it. It is used exclusively for making the limited diets, from my understanding, when I was searching for things to feed to Emma Nems.

 I'm back!

Sorry I've been ultra busy, but thanks for the continuing support.  

I have good news:  Bear has yet to have diarrhea since I last told you guys.  He has two-three firm stools per day.  But his RX food is almost gone, so I need to start making a switch.  The NB soudned good until someone mentioned a common allergen in it, so that probably isnt a good idea. 

He stills looks the same, weight wise, but I imagine it will take awhile for him to fill out.  I have noticed something with his coat.  I can take my fingers and quite literally pull out hair at will.  I know german shepherds shed a lot (he sheds a ton), but is it healthy for me to be able to pull out several hairs, root and all?

Depends on the type of hair you are pulling out.  My Kenya doesn't really "blow" coat, she just sheds hairs at a time, all year long.  You can run your hand on her back or brush her and always get cream undercoat.  If you are pulling out the guard hairs, that could be bad.

What about California Natural?  That is what my dogs are on now (I tried Natural Balance, had some runny poop issues).  Cal Nat is a limited ingredient diet.  Doing the bland elimination diet onto Cal Nat gave us zero poop issues.  

I'll look into california natural.

What's a guard hair?

The guard hair is the top coat, the hair that is usually darker, thicker, and sleaker.  These hairs should not shed like the undercoat.  Depending on the dog's color, the undercoat will be cream/white or grayish (a black dog or a rich black saddle will have grayish undercoat; the undercoat on the rest of the dog will be creamy colored).  The undercoat is shorter and fuzzier.

 Umm... why are you changing foods? He's having firm stools! Give his tummy time to heal, so he can gain weight. I'd keep him on the RX for a good 3 months, before I switched, personally. It's WORKING!

 ^^^^ What she said!!!!    It beats the heck out of expensive enzymes for EPI!

Just piping in about Natural Balance.  My dog has food allergies, which resulted in diarrhea, vomiting, and very itchy, dry skin.  I switched him to NB LID (limited ingredient diet) and he hasn't had any of these problems since.  I rotate between potato & duck, sweet potato & venison, and sweet potato & fish.  They have a new lamb and brown rice, but I don't buy that one because it does contain grains.  The good thing about NB LID is the simple formula - ONE carb source, ONE protein source.  Nothing complicated, just like the Rx food, but with much better quality ingredients.  All human-grade, and NO GRAINS.  The flaxseed can be an allergen in some dogs, but I haven't had any problems, and he's been on this food for 8 months.

Don't be concerned about the past recall issue.  It was with some of their canned formulas of venison and green pea flavors, and yes, it is fully explained on their website.

It does bother me somewhat that a carb is listed as the first ingredient, but the next two are the protein, and both from the same source.  As Glenda explained, duck "meal" is basically concentrated meat and is an excellent protein source.  It's more important to me what the guaranteed analysis is, and this food is 21% protein and 10% fat.  Since my dog turned 1 year old, I just supplement with an egg a few times a week to boost his protein intake.   Oh, and I also do 2 tbsp of plain yogurt every day.  A tub will last about 2 weeks, so it's very inexpensive and so worth it for their digestive health.

Oh, Harry is about 60 pounds and eats 3.5 cups a day of NB.

That all said, I agree maybe you keep Bear on the Rx food for another month or so, just to give his system more time to get back to normal.  Then if all goes well, you can try switching him (slowly!) to another food.  California Natural is also a good choice, but I only have experience with NB, so that's why I mentioned it.  The trick is to just find what works best for your particular dog.  All of us on this board have tried tons of different foods, all good ones, but not all great foods work well for all dogs.  Just wait until he's 100% before playing the food-switch game and I think you'll have fantastic results.

 Ok, I'll keep him on the RX food for now.  It's just way expensive and lesser quality, but it's still probably a good idea given his probably wrecked digestive system!

I don't know, I think the basic ingredients in the Royal Canin and Natural Balance formula are similar enough that you could slowly switch over. They both have potatoes, duck and fish oil and not much else as the main ingredients. Duck by-products is the main protein in Royal Canin. It could be anything in there (exclusive of feathers and a few other parts). I prefer to not feed a food with any by-products, but if it's in there I think at least meat should be higher on the ingredient list!

By product isn't bad for dogs, but it's not as easily digestible as real meat, and there isn't a federal standard for byproduct really.  Yes, it has to be exclusive of feet, beaks, feathers and fur, but that doesn't leave much other than fat and organs when you think about it.  And suppose the company gets a ton of say hearts one week (muscle meat) and a ton of livers (organ) the next, and this weeks byproduct is mostly heart, next weeks, mostly liver, well, that isn't great for the balancing of what the dog actually needs.  That's my biggest fear with bypoduct, other than the "ick" factor.  Organ should average 5% of the dogs daily diet, so it concerns me when companies start tossing in organ as bypoduct, willy nilly.

And, byproduct can include bone, if that is shown on the label, and in that case, since it can vary so much, do they individually balance the phosperous/calcium ratio on each individual batch?  This is essential to bone health so that worries me.

When you are paying such a huge price for food, in my mind, it ought to be human grade ingredients.

ETA:  I know they call GSD's german "shedders" but honestly, with the proper food, whatever that is, whatever food works BEST for them, shedding is minimal.  With Innova, mine shed some, other than the bi-annual blows, with Blue, gosh, we have almost NO shedding.

 It's working, though. I'd be so scared to switch, at least until he stabilized.

Emma was like that, when she was young. Diarrhea, all the time, emaciated all the time.... She looked terrible. She's 5, now, and a healthy 18 1/2 lbs. She was 12 lbs, on her first birthday. No muscle, no fat. It took finding what worked, and sticking with it for a full 6 months, before she stabilized and put on weight. Then? BAM! She got FAT overnight, LOL. I took her to the vet, and ran a bunch of bloodwork, and it was spot on perfect. I was thrilled, and cut her food in half, LOL. JMO, and of course,  your dog may very well be different than Emma Nems.

It IS working for the tummy issues, but causing additional issues with the excessive shedding.

I didn't really advocate changing NOW, I was just reflecting on my "shedders".