Cats throwing up

Is it normal for a cat to throw up? Two of my kittens threw up yesterday after they both ate. When I was cleaning up I saw foil in the puke but the other kitten didnâ€[emoji]8482[/emoji]t have anything other than food she just ate. Both kittens have been munching on a dog food lately. One of the kittens has just been seen by a vet for loose stool and blood in it. The vet put her on some kind of a powder made by Purina that she loves and tube of something that she enjoys as well. Her stools is no longer loose and she seems comfortable now but last night she puked and so did Gizmo. This morning I fed them all and Gizmo puked again which looked like his entire breakfast. I had the same issue with Marbles a month ago and he seems fine now. He was given some kind of medications and the vet told me to keep him off food for 12 hours, which has helped. I am wondering if this has anything to do with them getting into dog food? The vet said it is possible but it looks like Gizmo is trying to eat other things besides the dog food. I have been talking to my husband because I cannot figure out where in the hack did the cat find foil? We donâ€[emoji]8482[/emoji]t use foil in the house actually I ran out if it and have not purchased it for at least 6 months if not more. Any ideas?

Was it wet or dry food that was thrown up???

WHat are the names of the powder and tube???

Are the kitty dishes elevated ???

NO throwing up is not normal

You may need to redo the foods again... if he is seriously seeking out things to EAT that are nt food you might have a nutritional issue