dry food switch

My moms cat eat wet food mostly but I do add in a little dry food. I changed from Merrick purrfect bistro chicken dry for cats to California natural dry grain free, Have always used calif natural till the recall but now how gone back to both reg and grain free For mine and my moms.. Do not like all the powdered cellulose in  many dried food.

We have a older cat who is very thin who always liked the dry food. I ran out of the other dry food I stopped using and brought the new one in. I gave like 5 kibbles to each cat each day as a transition. They all seem fine but the older ill cat got diarrhea BUT I am not sure if its from that as I barely gave him any or a bad can of turkey and gibs it seems fancy feast changed something!! So today I tried again a few knibbles. I just do not know what to do? Can I introduce very slowly without mixing it with the old food (that I ran out of) or do I need to buy more of the old food to make a transition?? Or just feeding a spec a day of the new one??? I will say the cat is ill and will need to be put down down the road. But he has been eating well and seems happy. He was looking for the dry as I give it to the other cats and they just love it with no problems.The ill cat ate it right up.. Her cats are at my moms so I have to be careful as I only give the dry when I go for lunch and that is where the ill cat is.  Any ideas. I feel bad because the ill cat really wants his crunchies??? any ideas!!

It's hard to know what triggered the diahrea. As you said it could be the new dry or the FF. Or something else. There are 2 thoughts on this. The cat's system is rejecting the new food itself and will not grow accustomed to it. Or the cats system is reacting to the change itself in which case given some time it will accept the new food and the diahrea will stop.

My feeling is since this cat is weak to begin with, it is best to avoid diahrea which makes matters worse. So I would go back to the diet where his stool was ok and work to resolve the diahrea either with meds or natural supplement.

Had it been a healthy cat I would probably continue on the new food and try to overcome the diahrea with treatment and time.

His Diarrhea cleared up immediately. Been okay since. Who knows.

just to add I am in a very difficult position. Mom has alzheimers does not see anything wrong with the cat. If I say anything bad about him she gets upset. I know if I go to the vet they will say put him down or do blood tests and who knows what else. He is 16 yrs old. Mom does not have enough money to do a bunch of tests. I have called Vets and they could care less that my mom is elderly, ill and having financial issues. But she LOVES her cats as do I. I am watching the cat VERY carefully. He still is eating and poops and seems content for now though we all know how cats hide things.  I have had cats my whole life and I will do what has to be done when I feel its time. Its just so hard with my mother there and I have to make the decision myself have no family or friends helping me out as it is with mom and now the beloved cat is all up to me. It amazes me how vets charge so much and seem to have no heart. Even house calls is high and cremation more. But I will do what I have to to give her cat the best when it comes time, somehow.

You wonder why there are so many strays or abandoned cats because Vets are so high priced people cannot afford them and there seems no understanding, Cremation is doubled at vets. Pick up and bring back. Why isn't there one price divided by how many cats are taken and brought back. They charge for each individual cat. I have never cremated a cat before always buried them. It just boggles my mind how Veterinarians are and have become. All about making money

It's big business, doctors don't cut deals neither do vets.

Vultures except for a very few good ones.