Why Is My Dog Vomiting Food and Having Diarrhea?

Nutrition & Diet 📅 August 10, 2026 👁 7972

📝 Summary

Vomiting undigested food and diarrhea can mean a contagious disease in an unvaccinated dog, or simple gastritis and a sudden diet change in adults. Distemper is a serious cause — starting with food vomiting, then weakness, fever, and tomato-like bloody stool. Treat only under a vet's care, with rest, warmth, and disinfection.

1 Causes of Vomiting Food and Diarrhea

A dog’s vomit reflex is strong — it throws up harmful food in self-defense. In an unvaccinated dog, vomiting with diarrhea points to a contagious disease such as distemper, coronavirus, or another viral infection; in adults it more often means gastritis or a sudden change in food or feeding habits.

2 Distemper-Related Vomiting

Early signs are vomiting of undigested food; as it progresses the vomit turns white or gray-yellow, sometimes with a little blood. The dog then grows weak, may run a fever, becomes dull and reluctant to move, eats less, and keeps vomiting and having diarrhea. Late stage brings diarrhea with the classic foul, tomato-sauce-like stool.

3 Treating Distemper Vomiting

Treat only at a proper clinic. Withhold food and water at first so the dog can rehydrate and recover, and keep up nutrition. Keep the dog warm — it will be dull and sleepy, which is expected. The first three days are the danger period; survive them and the risk drops. Disinfect the dog’s living area often, using a virucidal solution.

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