Why do dogs eat their vomit
Dogs are attracted to smells which humans often find disgusting, as are other animals. The smell of vomit might actually be appealing to them. Most dogs are naturally inclined to eat just about anything that seems edible to them.
Simple. because THEY'RE DOGS!!!
Waste not, want not.
Dogs might be able to smell food that they had eaten earlier...and they are very eager to eat it again...
Cause they think there cool