I'm guessing that she got into the dog food, not that you feed her only dog food as many are assuming here.
It's going to be a feed her in a separate room; let her out once the dog has finished eating.
I'm not sure what the symptoms are, so you might want to share those. If it includes vomiting of continual diarrhea, I'd call the vet. Until then, keep fresh water available (in her own bowl) at all times in multiple places. If she will take it, a good wet kitten food will help rehydrate her (don't feed her dry food at all if she'll eat the canned food). Good brands for wet food: Merrick, Royal Canin, Iams, etc.
The problem is the dog food may have more salt, dangerous amounts of minerals/vitamins, more fat, and not enough of the things your kitten needs. Even if she just sneaks the food she isn't filling up on what she needs. Dog foods tend to be stuffed with corn and grains that cats can't digest, at any age. Try to find any kind of food that is GRAIN FREE.
Call the vet to be safe, and best wishes.