RX diets in a multi pet household

Earlier today one of my customers asked me if I could come up with an alternative to the cat food she is currently using. Her cat has kidney issues and the vet put her on a feeding rx diet regiment. My customer’s main reasons for coming to me for my input were not that the cat is not doing well since she started eating the prescribed food. Quite contrary, she is pleased with the results. But she is a little irritated about the price, which is about $26 for an 8 lbs bag. This is even more so a problem since she owns two more cats. They are now eating this expensive food as well and she is just having a hard time to keep the cats on individual diets. Now this is my question to the community: In a multi pet household how do you deal with the feeding? Is everybody eating the same? Are you for any reason required to feed specific diets to specific pets and if so, how do you handle that? Do you separate the animals during feeding time? This would be one way coming to my mind since I personally have had success with doing that and it saved me quite some money. Although I was brought up a little different. During my childhood when either of us, my sis or brother or myself had a cold, Mom made chicken soup and we all had to eat it regardless of whether we were sick or not. But, it wasn’t quite as pricey either. Today, 30 to 40 years later we all still are around. So, no harm was done. But I doubt that the cats being fed the rx food will get away unharmed over the long run. I took a quick glance at the labels, it’s a pretty restricted with regards to the nutrients. Let’s stick with that topic for today. On the topic rx diet watch out for a bunch more questions to come over the next few days.