Our cat's fur always seems somewhat dry. She is a black cat and also has some white dandruff...not a lot but some. She eats wet canned food and dry Iams and drinks lots of water. I do comb her fairly often to remove the dead dry fur. I bought capsules at the pet store and that did not seem to do any good.  I bought some powder to sprinkle on her food and she left the food.  Any suggestions?