Hello, my name is***** and I have over 20 years of experience as a veterinarian. I'm sorry to hear that your fellow over-ate his kibble food, enough that his abdomen is bloated and he is noticeably uncomfortable.
The great news is that he is a small dog and I have never seen true bloat (gastric dilatation) and subsequent volvulus (twisting of the stomach) occur in a small breed dog. It also sounds like his color is good, which means he isn't too stressed or shocky.
He has what is known as food bloat, distention of the gastrointestinal tract due to overeating.
We need to make sure that he takes in enough fluids to keep the food soft and able to move through his gastrointestinal tract rather than getting too dry leading to an impaction. Offer small amount frequently of fresh water, ice cubes to lick, and warmed low salt chicken or beef broth to drink.
Mineral oil won't be helpful, and if he vomits he could aspirate it so I don't recommend it.
We also need to make sure that he isn't overly active which can lead to swallowing air or painful intestinal cramping. Slow walks are fine to keep things moving, but running and overly rambunctious play should not be allowed.
His elevated respiratory rate is likely a consequence of feeling uncomfortable and the increased work he has placed on his heart to pump blood through an overfull abdomen.
I would not feed him for a good 24 hours. His stomach should look almost normal before he is fed again. When you do feed him, feed him roughly 1/4 the amount you normally would twice daily. Slowly increase meal size back to normal over the next few days.
You can expect that he will most likely have some diarrhea, but that should clear up on its own over the next 48 to 72 hours.
If he attempting to vomit but unable to do so, his belly looks more distended and very tight, or he won't lay down and settle, or he is pawing at his mouth or staggering, then I recommend he see a veterinarian immediately as that can be a sign of a food impaction, a rare occurrence but life threatening if allowed to progress.
As long as he remains relatively bright, takes in plenty of fluids and is passing stool, and has an appetite when he is finally fed then he should return to normal over the next few days.
I know it is hard to see him this way, but he should come along given time and great hydration.
Please let me know if you have any further questions.