my 7 year old cat who is one of 3 brothers same litter is sick, he has been vomiting for a week now, he had small watery ones, kept eating, and drinking water at first, then about 4 days ago I watched him vomit alot of green color, mostly watery liquid and we were cleaning up alot of his liquid vomits, the last one same color but I saw darker ones in the basement from the night, he didn t eat today and now lays in front of the water bowl, not drinking and meowing, earlier today he was drinking just alittle water when I put it on in the tub, a week ago was when I heard one of the cats in the middle of the night knock down what I later found next day a box with styrofoam and plastic that I was finding in the liquid vomits not knowing yet which one.