Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your wee one’s situation, and wanted to help.
How long ago did you give Zofran? What milligram was it and how much does he weigh?
Has the vomiting settled with this?
Are his gums pink or pale/white? Moist or sticky?
If you press on his belly, does he have any discomfort, tenderness, or tensing?
Could he have eaten something he should not have (ie bones, toys, plants, chemicals, etc)?
Has he had any diarrhea?
Any issues passing urine?