As soon as we realized Ruthie was sick, we went into Food Is Medicine mode with her. Since she had been turning up her nose at her wet food, we bought fresh organic chicken liver, which we chopped fine and served in water to prevent dehydration. We sprinkled in a little bit of vitamin C, D and enzymedica probiotic. We tried adding homemade chicken broth instead of water, but she didn't go for that so much.
After a day of hand feeding (we were relieved she was at least eating!), we assessed that we needed more help; Ruthie still was not coming out from under the couch. Thankfully, our DVM does house calls and relies primarily on homeopathy (which our cat responds well to) and herbal medicine when needed. She visited a couple days into Ruthie's illness and determined that she had no blockages, she was not dehydrated and her health was generally good. She diagnosed some mouth sores and prescribed a one-time homeopathic remedy, as well as Diglyccerized Licorice, Slippery Elm and Aloe juice for her mouth. We've been mixing these in with Ruthie's food.
A day after the vet came, I also got the feeling we should give Ruthie some Cod Liver Oil on a daily basis. I went to our coop and looked for CLO that did not contain any added essential oils or flavorings (cats cannot handle essential oils). I looked and looked and eventually found two types (same brand, Nordic Naturals) in the pet section. The one that I bought says "For Medium to Large Dogs" on it, but it was a better value and product than the one marketed for cats. We give her 1/4 teaspoon by dropper each night before feeding her. She seems a bit less offended each time. And she is doing great!
To maintain her wellness, we are feeding her "liver soup" (described in second paragraph) every other meal, and CLO every day. I have premade and frozen single servings of "liver soup" in ice cubes. Hope this helps you find wellness for your kitties!