If the vomiting happens more than three times in an hour, or it goes on all day, call your vet. If your dog is a puppy, a senior, or has a medical condition, be extra careful. And if you ever see blood (red or brown coffee-ground-looking stuff), that’s a one-way ticket to the clinic.
Also, if your dog is acting like they’re in pain—whining, pacing, or refusing to lie down—don’t wait. Better safe than sorry, and better annoying the vet than crying on the floor later.