If your dog seems unusually tired and refuses to eat, it’s a clear sign that something isn’t right. Fatigue combined with a lack of appetite can point to anything from minor discomfort to a serious health condition needing urgent attention.
We outline the common causes of dog fatigue and not eating, what you can do at home, and when to seek veterinary help.
Why Is My Dog Fatigued and Not Eating?
Your dog may be fatigued and not eating due to illness, pain, infection, digestive upset, or underlying conditions like kidney disease, heart problems, or even stress. When these symptoms appear together, it’s often a sign the body is trying to fight something off or is in distress.
Common Causes of Dog Fatigue and Not Eating
1. Illness and Infection
Viral or Bacterial Infections
Dogs suffering from infections such as parvovirus, kennel cough, or leptospirosis often become lethargic and lose their appetite.
These illnesses can also cause fever, vomiting, or diarrhea.
If your dog is up to date on vaccinations, the risk of certain viral infections may be reduced, but infections from bacteria or parasites can still occur, especially from contaminated food or water.
Organ Dysfunction
Issues with the liver, kidneys, or pancreas can lead to both fatigue and inappetence.
For example, pancreatitis can cause a dog to become weak and stop eating due to abdominal pain.
Kidney failure can result in toxin buildup, which makes your dog feel sick, while liver disease may present with yellowing of the eyes or gums.
2. Pain or Injury
Musculoskeletal Pain
Arthritis, joint issues, or soft tissue injuries can cause a dog to move less and seem tired. They might also avoid eating if standing or moving is painful.
You might notice your dog hesitating to climb stairs or showing stiffness after lying down for a while.
Internal Pain
Pain from internal issues, such as gastrointestinal problems or urinary tract infections, may cause your dog to feel unwell and uninterested in food.
Watch for signs like licking the belly, stretching repeatedly, or straining to urinate.
3. Heatstroke or Overheating
Fatigue and refusal to eat may result from heat exhaustion, especially during hot weather or after intense activity.
Other signs include panting, drooling, red gums, vomiting, and collapse.
Brachycephalic breeds (like Bulldogs and Pugs) are especially vulnerable.
4. Toxin Ingestion
If your dog ingests something toxic—like chocolate, xylitol, grapes, or certain plants—it can cause sudden weakness and appetite loss.
Vomiting, diarrhea, or seizures might also follow.
If you suspect your dog may have eaten something harmful, contact your vet or poison control immediately.
Related: Dog foaming at mouth and not eating (Here’s why)
5. Stress and Anxiety
Significant changes like moving homes, a new pet, loud noises (e.g., fireworks), or being left alone can trigger anxiety-related fatigue and appetite loss.
Other signs may include pacing, trembling, hiding, or destructive behavior.
6. Heart Disease
Dogs with heart problems may experience low energy levels and disinterest in food. Coughing, labored breathing, fainting, or swelling in the abdomen are other warning signs.
Early diagnosis through a vet exam and diagnostic imaging can improve long-term outcomes.
7. Cancer
Cancer can sap a dog’s energy and appetite, especially if it has progressed or affects organs like the liver or intestines.
Tumors can be internal and not easily visible, so bloodwork or imaging may be needed to confirm.
8. Medication Side Effects
Some medications, including antibiotics or pain relievers, can cause drowsiness or nausea, leading to fatigue and decreased appetite.
If your dog recently started a new medication, ask your vet whether side effects are to blame.
9. Age-Related Changes
Senior dogs may slow down and become pickier with food, but significant fatigue and loss of appetite are not normal aging signs—they often signal disease.
Arthritis, dental disease, or cognitive decline may also play a role.
What You Can Do at Home
1. Check Temperature and Hydration
Use a digital pet thermometer to check for fever (above 102.5°F/39.2°C) and gently pinch their skin or check their gums to assess hydration.
A dry nose or sticky gums may also indicate dehydration.
2. Offer Tempting Foods
Try bland options like boiled chicken and rice or a vet-approved wet food to entice eating.
Slightly warming the food may enhance its aroma. Avoid feeding fatty or spicy human foods.
3. Create a Calm Environment
Limit noise, foot traffic, or other animals that may be adding stress.
Ensure your dog has a quiet, comfortable place to rest with access to water and shade.
4. Monitor for Additional Symptoms
Track signs like vomiting, diarrhea, coughing, limping, changes in urination, or bloated abdomen.
These can help your vet narrow down the cause. Keep notes on when symptoms began and any changes in behavior.
When to Call the Vet
Call your vet if:
Your dog hasn’t eaten for more than 24 hours
Fatigue persists for more than a day
You notice vomiting, diarrhea, coughing, or limping
Your dog has a fever, bloated belly, or labored breathing
Your dog is very old, very young, or has an existing medical condition
Prompt treatment can prevent complications and improve outcomes—especially in cases involving organ failure, infections, or toxic exposures.
Read more: Old dog not eating (What it means and what to do)
If your dog is unusually tired and turning away from food, don’t ignore it. While the cause may be mild, it could also indicate a more serious condition that needs timely attention.
A calm home environment and a quick call to your vet are your best first steps.