Im worried about my German Shepherd!!!!

Question
I have a beautiful female German Shepherd that is about 1 1/2 years old. She weights approx 50 pounds and she is really skinny in her mid section, her ribs show as well as her hips.
She is up to date on all of her shots and her appitite is normal. She eats 2 3/4 cups of IAMS large breed dog food with a little bit of wet can food (approx 1/3 cup) 2 times a day (morning/evening)
She has the WORST breath that smells like something is rotting but not all the time.
I'm worried that she has maybe cancer or something that could possibly be fatal.
I will take her to the vet again but I am just soooo worried I need to find something out before I take her.
She is my baby.
Thank you so much for your help!

Answer
If her appetite is normal, you should be able to bring her up to a normal weight just be feeding her more.  It is not normal for a dog not to eat enough to keep itself in reasonable condition.  Shepherds often insist on showing a little rib, but not what you are describing.  

Take a fresh stool sample for the vet to check for worms.  

The Iams is a fine product.  It shouldn't need the canned food added.