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Dog Loss of Appetite: When to Worry & What to Do

A practical guide to tell mild from serious — but when in doubt, always ask your vet.

Last reviewed: 2026-09-05 · Reference ranges: ASPCA, Pet Poison Helpline & Merck Veterinary Manual

CALL YOUR VET

Veterinary advice recommended today — For most cases, follow the home-care steps below and call your vet the same day if warning signs appear.

What it can look like

Dogs can skip a meal when it is hot or stressful. Not eating for more than 24 hours, especially with vomiting or lethargy, deserves a vet call.

Common triggers to consider

  • Dental pain, sore mouth or a painful tummy
  • Upset stomach after something new
  • Fever, infection or underlying illness
  • Anxiety, heat or change in routine

When to call your vet

Contact your vet if any of these apply:

  • Refusing food for more than 24 hours
  • Not drinking, or vomiting and diarrhea as well
  • Weight loss, hiding away or obvious pain

What to do right now

Try warming the food or offering a small amount of bland chicken and rice. Do not force-feed. Keep fresh water available and call your vet if it continues.

What the vet may do

Your vet may check the mouth and teeth, take blood work and imaging to find the cause, and may offer appetite support.

Common questions

How long can a cat go without eating?

More than 24 hours without food is a serious warning sign in cats — a short fast can contribute to liver problems. Contact your vet the same day.

My dog is eating less but seems fine — should I worry?

Try offering a small bland meal and monitor for a day. If appetite does not return within 24 hours, or your dog develops vomiting, diarrhea or low energy, call your vet.

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Same symptom in Cat: see Cat Loss of Appetite — causes and home care can differ by species.

This page is educational triage information, not a diagnosis. Pets vary — when in doubt, ask your vet. In an emergency, contact your local emergency clinic or pet poison hotline directly.