yes rice is a good idea. i worked at a kennel and chicken and rice is the go-to for dogs not feeling well. if your dog is very active then potatoes or rice would be a good adjunct. you could emulate the ratio of many types of dogfoods if you read the packages' assay(proper word usage rhere). creatine monohydrate could be very good for your dog as they require exogenous creatine for muscle, nerve, brain development. every week for one day a safe(within normal consumption generally) dose of creatine could be added to water(no taste) or a pill. i really think this could make a big difference as studies show the cognitive&physical benifits in people. beta alanine is another one but you should ask a vet about contraindications. this clears lactic acid and reduces sore muscles. the soap you use on your dog should be kirks castille and washing soda.. its clean rinsing and will strip dirt well. a little dish soap if your dog is really dirty.