Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.
Now there is no record of your previous question, if you would like to give me a history on William that would be helpful.
Otherwise, since you noted that he didn't eat breakfast, has he had any retching, gagging, lip licking, drooling, or vomiting?
Can he keep any water down?
Are his gums nice and pink (not white/pale)? Moist or sticky?
If you press on his belly, does he have any tensing, tenderness, discomfort, or pain?
Could he have eaten anything he should not have (ie bones, toys, plants, chemicals, human meds, etc)?