Hello, I'm Dr. Deb and will do my best to help you today.
Ingestion of this amount of bacon grease wouldn't constitute a toxic
issue for him but this amount of fat might predispose him to pancreatitis
given he's such a small dog.
If he just ingested the grease (<1 hour), then you could consider trying to remove it from his stomach
if you have 3% hydrogen peroxide before he has a chance to absorb it. The dose would be 1 teaspoon mixed with some bread, then walk him around and repeat the dose in 15 minutes if necessary.
Not all dogs will vomit when peroxide is given but most will.
If you don't induce vomiting, then signs to monitor will be the development of looser stools within 12-24 hours; a bland diet of chicken
and rice should resolve this problem.
If he becomes lethargic, has abdominal pain, vomits and/or has profuse diarrhea,, then a vet visit may be prudent.
I hope this helps and that he suffers no significant ill effects from ingestion of this grease. Deb