The psyllium husk is taken internally and acts directly in the large intestine to absorb toxins. It can also relieve constipation and diarrhea.  Because psyllium seed and husk are highly demulcent: they swell when mixed with liquid to stimulate bowel elimination.  This provides a mucilaginous coating to the intestines, providing bulk to the stool making it useful for both constipation and diarrhea.  By moistening membranes, psyllium soothes irritation and absorbs digestive toxins. Mix 1/4 to 1 tsp. psyllium seeds with a cup of water and mix with your 50 lb dog's food. Start with smaller doses and work your way up to 1 tsp.

Psyllium interacts with many drugs and may be contraindicated for dogs with kidney disease.