Several things could happen if your dog eats coleslaw including: • A potential choking hazard from the raw cabbage. • Diarrhea • Vomiting • Digestive problems from the raw cabbage. Longer term health issues such as obesity and diabetes could occur from the high levels of sugar and salt. Overweight dogs also experience other health issues such as joint strain. In rare cases, your dog could die from onion toxicity from eating coleslaw but they would have to eat a huge amount of it and be left untreated for that to happen.