According to 15 Foods to avoid, it states that diary products should not be allow for cats and dogs. However, has an exception for plain yogurt and cottage cheese.
I used to give my cat the leftover yogurt on the surface of the cup (not plain, eg. Aloe Vera yogurt), and she enjoyed it. This is to give her some probiotic for digestion as she's getting old. Sometimes she will get soft stool the next day, but did not vomit. I thought this will be good since she tend to have very hard stool. Does this mean that it is safe for cats to digest minimial amount of such yogurt? Is it harmful to them in any way??