If I were you, I'd call the vet for advice. That's what I did when it happened to Prince last time. I hope you're allowed to make phone consultations with your vet...
Today, Prince has been vomiting all day. Since he has no more food to vomit, now his vomit is just gastric fluids, of course. It happened once before, for 2 days. He's weaker than usual, so I was scared when we went for our daily stroll in the garden that he might find it hard to walk. But he wanted very much to be outside, and I didn't prohibit it because sometimes animals know better than us what makes them feel better, and I know that earth and grass are healing elements that cats seek sometimes when sick. Indeed, he sat with his belly on the earth and grass for a long time and now seems to be feeling a lot better. I'm sooo relieved that he's been drinking lots all along! I keep changing his water so that the fresh water entices him to drink more, and it really works. I didn't give him any food since breakfast and he's not hungry.
Today, Prince has been vomiting all day. Since he has no more food to vomit, now his vomit is just gastric fluids, of course. It happened once before, for 2 days. He's weaker than usual, so I was scared when we went for our daily stroll in the garden that he might find it hard to walk. But he wanted very much to be outside, and I didn't prohibit it because sometimes animals know better than us what makes them feel better, and I know that earth and grass are healing elements that cats seek sometimes when sick. Indeed, he sat with his belly on the earth and grass for a long time and now seems to be feeling a lot better. I'm sooo relieved that he's been drinking lots all along! I keep changing his water so that the fresh water entices him to drink more, and it really works. I didn't give him any food since breakfast and he's not hungry.