Have you noticed that one of the links provided in Pom-Chi's profile actually recommend getting a dog from a responsible breeder who health tests and breeds towards the breed standard? ROFL...someone should get out their reading glasses...
Anyways my 'real' question is regarding my pooch. He's 2 yrs old...some kind of Hound mix. He's got this awful sensitive stomach. For awhile when I first got him up until he was like maybe 17 months or so he had diarrhea pretty consistently. I had all sorts of tests done...including testing his organ values to make sure he was digesting his food right. I started monitoring him very closely and decided his D was a result of eating too many kitty crunchies as it cleared up almost immediately.
However, in the last couple months his diarrhea has started back up. I put him on a bland diet...it seemed to get better so I switched him to a new food (thinking his old food had been making him sick) and then within a day he was back to the diarrhea (I switched slowly...that is not the reason). I brought him to the vet...they did all the standard tests (worms, giardia, etc.) and still nothing. He was put on Metronidazole just in case as well as a dose of Droncit. Still diarrhea. So I put him back on the bland. It cleared up right away. The only thing his original food and the food I switched him to have in common is they are both Lamb Meal (which is usually good for sensi-stomachs). Is it possible he's developed a Lamb allergy and that is why he's been having D?
I'm so sick of him always being sick and skinny...I really wish I had a solution!
Answer on DS: Have you noticed?
If a bland diet produces normal poops, and regular food produces diarrhea, my thought is that it's most likely the food as well.
Have you ruled out a grain intolerance? One of my dogs was skinny & vomited frequently when we adopted her. We switched her to a grain-free food after a bit of experimentation, and that did the trick. It's the only thing that helped her gain weight, only thing that'll maintain her weight, and only thing that keeps her digestive system healthy.
An allergy to lamb is definitely possible. Lamb used to be an uncommon protein source in commercial foods. It was strictly an "alternative" protein source for dogs with digestive problems, found only in specialty foods. Now it's in every food under the sun, dogs eat it from an early age and if they're prone to digestive intolerance, they have every chance to develop a lamb intolerance.
You can rule out some food allergies by making a simple bland diet with one meat and one carbohydrate source and feeding it temporarily. Like chicken and rice. If the dog tolerates that one meat & one carb by itself, you know he's not allergic to those particular things in his dog food. If he tolerates bland chicken & rice, but a chicken/rice dog food makes him sick, then you know it's another kibble ingredient he's allergic to.
Just my thoughts, hope this helps :)