Thanks for that! I didn't have your additional info when I first read your question, but now I can see more about Rocky.
It really sounds like Rocky is not feeling well!
There are a number of conditions that could cause the symptoms you are describing.
It would be good to check the colour of his gums to see if they look pale or white. If so, he may have internal bleeding. We see this in some dogs with a ruptured spleen tumor, but there are other causes. The blood loss causes the dog to feel awful and to not have any energy. It can also affect his breathing.
Another possibility is that he is having a serious problem with his heart. This can cause breathing issues and lethargy and inappetance as well.
There are other possibilities as well including kidney or liver disease.
When a lab does not want to eat, there is almost always a medical reason for it.
If you have access to an emergency veterinarian I would really recommend a visit today.
I hope everything is ok!
I hope this information helps! If you have more questions regarding this problem, just hit reply. If I am online I will respond right away. Otherwise I will respond as soon as I come online again. Or, if my answer is sufficient, then please hit accept. Thanks!
The above is given for information only. Although I am a licensed veterinarian, I cannot legally prescribe medicines or diagnose your pet's condition without performing a physical exam. If you have concerns about your pet I would highly advise contacting your regular veterinarian.