Walter was in my room (in a carpet) earlier when he suddenly did the heaving action (muscle contraction) as a symptom before he vomits. He did this in the past for a few times already so I know. Knowing that he is in the carpet, I immediately carried him and brought him outside with the assumption that he will continue to try and vomit. But I think that was stupid of me because it seems that I accidentally stopped him fulfill the event (vomiting as a protection mechanism). After around 2 hours, he still did not try vomiting again. Should I start to worry then? I want him to vomit any possible foreign object he has inside his tummy if that's what's happening here.

Responding to your post even though it was 2 days ago and probably resolved itself.

I hope he is OK at this point, and assume he is. Vomiting can be caused by a bunch of different things. In this case I am going to guess that he just wolfed his food and had an air pocket in his belly. You probably broke the bubble when you picked him up and carried him. A dog throwing up every now and then is pretty common. You definitely want to keep an eye out for repeated issues as that could be a sign of accidentally ingesting a foreign object (my dogs like to chew plastic...empty water/soda bottles, grooming brushes, Tupperware, etc.)

Thanks for the reply. Yes, I was actually waiting for him to vomit but he never did. I guess I need not worry then and I'm glad it was just out of my paranoia. In the past (in his 10 months of his life), he already vomited three times because of the Nylabone toy chunks he ingested and that got me worried.

That's the good sign. If you can tell what was causing the upset stomach, and it comes back up, then that's positive. It's the mystery that is a problem.

Way back when, before I discovered chows, I had a peke pup (25 years ago)... He started vomiting repeatedly when he was about 5 months old. No real clue what was wrong, no issues with food up until then, and he really didn't show too many signs. Vet discovered that he had swallowed a penny. Mouth was big enough for it to go in, but the rear parts were too small to pass it. It became lodged in his tract and we had to have surgery to remove it. Very scary and very expensive.

You are not wrong for worrying. Chows can have their own issues (bloat) that are life threatening. SO you want to be alert, but not neurotic. It can be a tough balance with young dogs.

Having lost our 13 year old chow this January to stomach cancer we watch our 3 youngsters for any sign of vomiting. Our vet tells us not to worry, she tells us the tell tale sign is their weight, if they aren't losing weight then it's probably something they ate. Hachi chewed part of his sister's name tag and swallowed it before we could get it away from him. Five days later he vomited it up. Dogs chew on everything and swallow all kinds of things. I think that Rory's Dad was right, if something is upsetting his stomach he will vomit it up