Need to change cat's feeding routine for med reasons, I'm lost!

Hello all. As a bit of background, I have 3 kitties - Connor, Murphy and Amelia. All 3 have been on a free feed schedule since we got them about 2 years ago. All 3 get dry food with an occational canned food as a treat.  Due to recent medical issues, their diets have had to be changed. First Amelia had some high kidney numbers (not sure what exactly) and the vet recommended switching to the k/d Science Diet food (kidney health). We just switched all 3 cats to it, and continued to feed dry food.

Murphy was just diagnosed with Feline Idiopathic Hypercalcemia. The vet said he needed to go on an all wet food diet ASAP, to prevent kidney stones and try to get his calcium levels down. He does have crystals in his urine at this point, but no stones yet. Being on the kidney diet for almost a month has helped him, he gained back 5 oz in body weight that he had lost due to the FIH. So the plan is to give Murphy the k/d canned food, and the other two k/d dry food.

So, the issues: First off, I don't know how to keep Murphy away from the dry food. Eventually we might switch them all to canned only, but my husband just lost his job so that isn't a viable option at this point. Second, since they have free-fed their whole lives, giving them food at a specific time doesn't work, because they don't understand they need to eat it right then. I've tried feeding Murphy in a separate room. He'll nibble the food but won't eat it all at once. Plus, when the other two hear the can opening they want canned too. Today Murphy nibbled the canned food and then went and ate the dry food. I really worry about his health and I don't want him to get kidney stones. How do I sort all this out?! Any advice greatly appreciated.

I think your best bet is to get them all on timed meals. It is possible to transition free fed kitties to timed meals, and the article below gives tips on to do it.

http://www.thecatsite.com/a/transitioning-free-fed-kibble-kitties-to-timed-meals

I agree with Vball.  You CAN, and probably should get all your cats on scheduled feedings, because, IMHO, both "sick" cats should be on canned food.  Kidney cats also need plenty of extra moisture, and what better way than to feed them wet food .  My kidney cat gets wet food, and I even add extra water to it.

BTW,  not sure feeding your FIH cat the kidney food is such a good idea, since the kidney food is really high in carbs, and the best diet for FIH cats is actually one that is low carb.  For FIH cats, " the best diet is a high-quality, canned or raw, high-meat-protein, moderate-fat, low-carbohydrate, grain-free diet should be 

tried" *.   I actually try to feed my kidney cat this way too, PLUS try to watch the phosphorus level to keep it under a certain level.  There are actually some over the counter canned foods out there that fit the bill.  Here is a food chart you can refer to  http://www.catinfo.org/docs/FoodChartPublic9-22-12.pdf  if your kidney cat gets tired of or doesn't like the canned kidney food.

*felineihc.org

Transitioning cats to scheduled feeding is do-able, even with the most stubborn ones.

@vball91 posted a link where you can find tips and tricks. It can be hard, it took me nearly 4 months to get Sophie to accept the schedule, but all is fine now. It just takes patience, and patience, and patience.