I buy my pet food at Canadian Pet Connection. They are owned by a father and son who take great care in their selection of pet food. I noticed they carry Oxbow rat food as well as Supreme Science Selective Rat food. I checked out the ingredients and the protein/fat amounts and it looks like a good food for rats. Also as a supplement, they offer Supreme Tiny Friends Farm Reggie Rat and Mimi Mouse Tasty Mix Rat and Mouse Food and treats. You can also find good quality CBD oil if your feel your rat could use some and you've done the research on it. They also carry lots of ferret toys which we all know, our rats love too.
