This page focuses on urgent assessment. Routine wellness exams, preventive care, and monitoring of stable conditions are provided through scheduled general wellness appointments.

Dog Not Eating – When to Worry and What to Do

A dog not eating can range from a brief appetite dip to a sign of serious or life-threatening illness, depending on the underlying cause and duration. Owners may also search this as “dog won’t eat,” “dog stopped eating,” “dog refusing food,” or “dog not interested in food.”

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Definition

Not eating (anorexia or reduced appetite) refers to a dog refusing food or eating significantly less than normal. This is a clinical sign, not a diagnosis.

Loss of appetite occurs when illness, pain, nausea, metabolic imbalance, infection, toxin exposure, or emotional stress interferes with normal hunger signaling. Even short periods without eating can quickly affect hydration, blood sugar, and energy balance.

In dogs seen in the Stittsville–Kanata area and elsewhere, appetite loss is treated cautiously because dogs often stop eating before more obvious signs of illness appear.

Who This Page Is For

Dogs refusing meals or treats they normally enjoy
Dogs eating much less than usual for more than one meal
Dogs turning away from food but still drinking or acting “mostly normal”
Dogs not eating along with vomiting, diarrhea, lethargy, or weakness
Dogs with sudden appetite loss and no clear cause

Who This Page Is Not For

A dog who skipped a single meal and returned fully to normal appetite within a short, predictable window

If you are unsure whether this is significant, that uncertainty itself warrants veterinary assessment.

Related Urgent Symptoms

Dog Lethargic And Weak
Dog or Cat Vomiting
Vomiting And Diarrhea
Distended Abdomen or Bloat
Pale Gums (Emergency)
Difficulty Breathing (Respiratory Distress)
Toxin Exposure In Dogs And Cats
Sudden Collapse (Syncope)

What This Can Look Like at Home

Owners may notice a dog sniffing food and walking away, eating only a few bites, refusing treats, or showing interest in food but not actually eating. Some dogs chew slowly, drop food, or avoid hard kibble.

Appetite loss may occur alone or alongside subtle changes like quieter behavior, restlessness, lip-licking, or mild nausea.

Why This Can Be Hard to Judge

Dogs frequently display early misleading normalcy — appearing outwardly stable while internal problems are developing. A dog may still wag, drink water, or eat small amounts even as dehydration, infection, pain, or metabolic imbalance worsens.

Appetite loss is often dismissed as picky eating, stress, or a temporary upset. However, many systemic illnesses cause appetite loss before more obvious signs appear, making it an unreliable symptom to judge without testing.

The Improvement Trap

A dog may briefly resume eating after rest, hydration, or a tempting food. Temporary improvement does not equal resolution.

Conditions such as pancreatitis, gastrointestinal obstruction, infection, toxin exposure, dental pain, or hormonal disease may fluctuate — improving briefly before appetite drops again. Waiting for appetite to “fully return on its own” can delay needed care.

What Is Easy to Miss at Home

Subtle nausea (lip-licking, swallowing, drooling)
Mild abdominal discomfort or guarding
Dental pain affecting chewing
Reduced water intake or reduced urine output
Weight loss over just a few days
Slight lethargy that accompanies appetite loss
Pale gums or dull hair coat

Appetite changes are often the earliest clue that something systemic is wrong.

When This Can Be an Emergency

Loss of appetite should be treated as urgent or emergent if any of the following are present:

Not eating for 24 hours or longer
Vomiting or diarrhea alongside appetite loss
Lethargy, weakness, or collapse
Pale gums or breathing changes
Distended abdomen or retching without vomiting
Known or suspected toxin exposure
Signs of dehydration (dry gums, sunken eyes)
Puppies, seniors, or dogs with chronic disease
Rapid weight loss or refusal to drink

How Veterinarians Assess This

Clinical signs alone cannot reliably determine severity.

Loss of appetite can look similar at home while representing very different internal disease processes. Diagnostic testing is how veterinarians determine whether a condition is mild and self-limiting or serious and potentially life-threatening, and how they guide appropriate care.

Diagnostic testing may include:

Full bloodwork and electrolytesTo evaluate for inflammation, infection, anemia, dehydration, metabolic abnormalities, and organ dysfunction that commonly cause appetite loss.
UrinalysisTo assess hydration status, kidney involvement, and systemic disease that may not be apparent on bloodwork alone.
Blood glucose testingTo identify hypoglycemia or diabetic complications that can suppress appetite and cause weakness or collapse.
Pancreatic lipase testingTo evaluate for pancreatitis, a common and often painful condition that frequently causes sudden refusal to eat.
Abdominal X-rays and/or abdominal ultrasoundTo assess for gastrointestinal obstruction, inflammation, masses, organ enlargement, fluid accumulation, or other abdominal disease affecting appetite.
Thoracic X-raysTo evaluate for cardiopulmonary disease, infection, neoplasia, or metastatic disease that can cause systemic illness and appetite loss.
Infectious or vector-borne disease screeningTo assess for tick-borne or other infectious diseases that may cause lethargy, weakness, anemia, fever, and reduced appetite.

Diagnostic testing is what determines severity and guides appropriate care.

Veterinary Differentials - Serious / Must-Rule-Out First

Pancreatitis

Inflammation of the pancreas can cause significant abdominal pain, nausea, and systemic illness, leading to sudden refusal to eat even when outward signs appear mild.

Testing may include full bloodwork, pancreatic lipase testing, abdominal ultrasound, and abdominal X-rays.

Acute Kidney Injury

Rapid loss of kidney function can cause toxin buildup, nausea, and profound malaise, often presenting first as appetite loss.

Testing may include bloodwork, electrolytes, urinalysis, abdominal ultrasound, and blood pressure measurement.

Hypoadrenocorticism (Addison’s Disease)

This hormonal disorder can cause vague signs such as lethargy and not eating, but may progress rapidly to collapse if untreated.

Testing may include electrolytes, blood glucose testing, baseline cortisol, and ACTH stimulation testing.

Diabetic Ketoacidosis

A severe metabolic complication of diabetes that can suppress appetite and cause dehydration, weakness, and systemic instability.

Testing may include blood glucose testing, bloodwork, electrolytes, urinalysis, and blood gas analysis.

Pyometra (Intact Females)

A life-threatening uterine infection that frequently presents with appetite loss before more obvious reproductive signs appear.

Testing may include bloodwork, abdominal ultrasound, abdominal X-rays, and inflammatory markers.

Gastrointestinal Foreign Body

An obstruction can cause nausea, pain, and loss of appetite even before vomiting becomes severe.

Testing may include abdominal X-rays, abdominal ultrasound, and bloodwork.

Bacterial Sepsis

Systemic infection may initially appear as reduced appetite and lethargy before progressing to shock.

Testing may include bloodwork, lactate measurement, blood cultures, imaging, and infectious disease screening.

Neoplasia (Systemic or Abdominal)

Certain cancers can cause appetite loss through pain, inflammation, organ dysfunction, or metabolic effects.

Testing may include bloodwork, thoracic X-rays, abdominal ultrasound, cytology, or biopsy.

Veterinary Differentials - Common / More Typical

Gastroenteritis

Inflammation of the stomach and intestines can cause nausea and reduced appetite, sometimes without obvious vomiting or diarrhea initially.

Testing may include bloodwork, fecal analysis, abdominal X-rays, and abdominal ultrasound.

Periodontal or Oral Disease

Pain from dental disease, oral infections, or fractured teeth may cause reluctance to eat despite interest in food.

Testing may include oral examination under sedation, dental X-rays, and bloodwork.

Chronic Enteropathy / Inflammatory Bowel Disease

Ongoing intestinal inflammation can suppress appetite through discomfort and malabsorption.

Testing may include bloodwork, fecal testing, abdominal ultrasound, and intestinal biopsy.

Chronic Hepatitis or Liver Disease

Liver dysfunction can cause nausea and appetite loss before jaundice becomes visible.

Testing may include bloodwork, bile acids testing, abdominal ultrasound, and liver cytology or biopsy.

Osteoarthritis or Musculoskeletal Pain

Chronic pain may reduce appetite indirectly by lowering activity, comfort, and interest in food.

Testing may include bloodwork, orthopedic imaging, and response to pain-directed diagnostics.

Drug-Related Side Effects

Certain medications (e.g., antibiotics, opioids, chemotherapy agents) can reduce appetite as a secondary effect.

Testing may include bloodwork and medication history review to assess systemic impact.

Safety, Psychology, & Peace of Mind

Appetite loss is stressful for owners because it feels subtle yet concerning. The difficulty is that both mild and serious conditions can look identical early on.

Veterinary assessment reduces uncertainty by identifying whether appetite loss is due to temporary upset or a developing medical emergency. Early evaluation protects hydration, prevents complications, and provides clarity rather than guesswork.

Frequently Asked Questions

Is a dog not eating an emergency?

Sometimes. A dog not eating for more than 24 hours, or refusing food alongside lethargy, vomiting, diarrhea, pale gums, abdominal swelling, or weakness, should be assessed urgently. Appetite loss can be the first visible sign of serious internal illness, even when other symptoms seem mild.

Why is my dog not eating but still acting normal?

Dogs often mask illness, and appetite loss may appear before obvious changes in energy or behavior. Conditions such as pain, infection, metabolic disease, or organ dysfunction can reduce appetite long before a dog looks outwardly unwell.

Can appetite come back and still be serious?

Yes. Temporary improvement does not equal resolution. Appetite may briefly return with fluctuating conditions such as infection, inflammation, toxin exposure, or hormonal disease, then worsen again as the underlying problem progresses.

Why are diagnostic tests needed if my dog just won’t eat?

Outward behavior alone cannot determine severity. Diagnostic testing identifies internal causes—such as infection, organ dysfunction, inflammation, metabolic disease, or obstruction—that are not visible at home and helps guide appropriate next steps.

What should I do right now?

If your dog skips one meal but is otherwise normal, monitor closely. If appetite loss persists beyond 24 hours, worsens, or occurs with other symptoms, same-day veterinary assessment is recommended.