Hello,
The loose stool and the pale gums are a warning sign that the dog may be lacking the nutrients it needs to fight off infections and disease. Have you ruled out the option of possible hookworms? Often a dog will present with these symptoms. The following link will tell you more about it in detail:
http://www.drpetra.com/Dogs/Hookworm%20Infection%20in%20Dogs.htm
There are several other diseases that can cause these symptoms as well, and you can read about them at the following:
http://www.lookd.com/dogs/diseases.html
In any case, if the dog seems to be getting worse, or showing signs of pain. You should get him to a Vet for the proper workup in ruling out the definite cause.
The following is a diet you can try to see if it might help ease the discomfort:
http://www.placervillevet.com/canine%20gastroenteritis.htm
I hope this helps you out. if not, write again and someone will assist your concerns.
Take care..
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