I know its Daisy.. cause if skin problem highly will transfer to other dog. So ask you if Happy anything wrong. If nothing wrong with Happy, then maybe it is not skin problem. It maybe rashes, due to allergies/sensitives that only affects Daisy. Since no 2 dogs having same antibody.

Don't feed too much glucose, and best don't feed glucose without vet prescription always. Later high sugar in blood. Recently I just hear about a case with high blood sugar. This puppy was very weak. At first thought of feeding glucose because puppy is not eating. Luckily the vet did a glucose test, it is very high in sugar. Feed more glucose means... making it more weak. So they did salt drip.