Beautiful kittens

I have been baby sitting 3 kittens for my mother in law since Thursday night,now today is Saturday and since Thursday they ate ,walk,and play now this Saturday morning 2 where ready to eat and 1 was slump over heavy breathing but lifeless no head control at all I rub him to keep him up was scared iffy not he will die,took him to my job to see if my boss can help gave him fluids and a bath and he came back to life 2 hours later,went home to feed the other 2 and 1 of them was acting like the one I brought in omg I took all 3 with me so I can run errands ,ended up at pet Co trying to see if I can gets something, spoke to people there and I said I think bowel needs to be moved but that wasn't it cause one or they all been peeing and diarrhea I think something neurological is going one,I left and said going to keep eye on them ,now the 3rd one is walking wobbling, can't control head won't eat ,mind u just 1 hour ago I feed him before I went in petco now it's like he has same system too ,eyes closing ,weak now I filled up syringe to try feeding and realize the cat milk brand whiskas I got at stop and shop says 04-26-16 and today is 10-22-16 can this cause there illness all of a sudden?

How old are these kittens? It sounds like they all need to see a vet urgently. Stop feeding the whiskas milk. It is meant as a treat and has little nutritional value. You can use kmr or goat milk.