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.
Again I do apologize that my colleagues could not aid you sooner, but can you tell me:
How long has he had these signs?
How old is he and is he neutered?
When did he last pass a stool? Was it normal, diarrhea, or hard?
Are his gums pink or pale/white? Moist or sticky?
If you press on his belly, any tenderness, or tensing?
Could he have eaten something he should not have (ie bones, toys, plants, chemicals, etc)?