Vomiting is more of a sign of indigestion or acid reflux or eating a non food item then Rabies.
Dogs get GI upsets and viruses all the time.
If you think he swallowed a non food item and has a blockage he shoud be seen ASAP.
He can have Immodium, kayopectate or any OTC at www.wolfdancer.org/health scroll down for products and dosages.
He may have a bad tummy ache. 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
Go very slow so he does not throw it up.
Dogs get dehydrated and hypoglycemic very easily from vomiting.
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.
Do not allow him to drink a lot at a time If he throws up water, he can lick ice Keep him on that very light diet of boiled chicken or chop meat for 48 hours after the stool is normal.
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..