Many things can cause vomiting in dogs, including toxins, various drugs, diseases or even parasitic infections. And, well, we all know that dogs vomit sometimes. Acute vomiting is when vomiting suddenly happens and can last anywhere from a few minutes to a few days. Many times, a dog may keep vomiting even after the stomach is empty of everything except bile. If your pet experiences acute vomiting, contact your veterinarian.