Help for aging Dog :)

I just got my bottle of CS and wanted to use it for my aging LabX doggy. She just doesn't have the spark that she used to, and I was hoping to help her with CS. I don't know what is going on internally and I live hundreds of miles from a vet who would even understand or care. She has allergies or something going on with her feet. She gets sores on them and is constantly chewing on them which seems to cause her discomfort and drives us nuts.

She weighs about 45 pounds and still likes eating and drinking. I was wondering how much CS I should put in her water.