I am so sorry your boy is not feeling well.
There is a nasty canine flu going around:
He may have an upset tummy or even pancreatitis.
Bloat is always very concerning:
Give him a half a pepsid (famaatodine)
I would pick up any dog food.Try a small amount of boiled chicken with all fat drained off, chop meat , or baby food with no onion, beef, turkey, etc add cooked white rice or infant rice cereal.
human baby food in meat flavours (check that there are no onions or garlic in the ingredients) and mix that with warm water and offer that, or syringe it in little bits into your boy's mouth. Beech Nut makes a line of baby food that has nothing but meat (beef, chicken, turkey or veal) in it. Here's a link: http://www.beechnut.com/Our%20Baby%20Food/Results.asp If you cannot find this, you could find another meat baby food - just read the label carefully to be sure there are no onions, onion powder, garlic, or garlic powder in it.
Go very slow so he does not throw it up.
Add unflavored pedialyte to his water 50/50 to hydrate him and balance his electrolytes.
Put a drop of pancake syrup on his tongue to raise his blood sugar in case he is a bit hypoglycemic. That should perk him up.
Also give him one teaspoon a day of plain yogurt to keep "good" bacteria in his system.
If he develops any abdominal pain, bloating, constipation or cannot keep anything down he needs to be seen by a vet.
Please let me know how he is doing. I will always be here for you
I hope your baby feels better very soon..
Best wishes for him,