If your dog is not eating and appears sick, it can be worrying. Loss of appetite in dogs—especially when combined with signs of illness—could point to a wide range of health issues, some minor and others serious.
We outline the causes behind why a dog is not eating and appears sick, the signs you should watch out for, and when to take your dog to the vet.
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Why Is My Dog Not Eating and Acting Sick?
When your dog is not eating and appears sick, it’s often a sign of an underlying health issue that shouldn’t be ignored. Common causes include gastrointestinal upset, infections, dental pain, poisoning, stress, or chronic conditions like kidney or liver disease.
Even skipping one or two meals can be concerning if it’s accompanied by symptoms like vomiting, lethargy, diarrhea, or behavioral changes.
Signs Your Dog Is Not Eating and Feeling Unwell
Besides refusing food, a sick dog may exhibit other symptoms depending on the underlying cause. Look out for the following warning signs if your dog is not eating:
Vomiting or diarrhea
Lethargy or weakness
Drooling or pawing at the mouth
Coughing or nasal discharge
Labored breathing
Pale gums
Sudden weight loss
Hiding or behavioral changes
Excessive thirst or dehydration
When your dog is not eating and shows any of the above symptoms, it’s essential to observe closely and seek veterinary attention if the issue continues.
Causes of Dog Not Eating and Appearing Sick
1. Gastrointestinal Problems
One of the most common reasons a dog is not eating and sick is gastrointestinal upset.
Conditions like gastritis, gastroenteritis, or intestinal blockages can cause nausea, vomiting, and discomfort, leading to a lack of appetite.
Dogs may eat something they shouldn’t—like spoiled food, grass, or foreign objects—which irritates the stomach lining.
If your dog has not eaten in over a day and is vomiting, has diarrhea, or shows signs of bloating or abdominal pain, it’s time to call the vet.
Related: Dog diarrhea and not eating (Explained)
2. Infections and Viruses
Viral or bacterial infections can lead to your dog feeling ill and refusing to eat.
Conditions such as canine parvovirus, distemper, kennel cough, or leptospirosis can severely affect your dog’s health.
Dogs not eating and sick due to infections usually also show symptoms like fever, coughing, nasal discharge, or vomiting.
These illnesses can be life-threatening if not addressed early, especially in puppies and unvaccinated dogs.
3. Dental Problems
If your dog is not eating but otherwise seems alert, check their mouth.
Dental issues like gum infections, broken teeth, abscesses, or oral tumors can cause pain while chewing, leading your dog to refuse food.
Bad breath, drooling, or pawing at the mouth are telltale signs.
A vet can conduct a dental exam to determine if mouth pain is behind your dog’s loss of appetite.
4. Stress and Anxiety
Dogs are sensitive to changes in their environment or routine.
A move to a new home, loud noises (like fireworks or thunderstorms), new pets, or separation anxiety can lead to stress-induced anorexia.
When stressed, dogs may not eat, appear lethargic, hide, or even exhibit gastrointestinal symptoms like vomiting or diarrhea.
If your dog is not eating and acting sick but has no fever or other clear symptoms, emotional stress could be the cause.
Related: Dog licking and not eating (Explained)
5. Ingestion of Toxins or Poisoning
A sudden refusal to eat, vomiting, and lethargy could be signs your dog has ingested something toxic.
Common household toxins include chocolate, xylitol (found in sugar-free gum), human medications, antifreeze, and certain plants.
If your dog is not eating and shows signs like tremors, disorientation, excessive salivation, or seizures, seek emergency veterinary care immediately.
Early intervention can be life-saving.
6. Organ Disease or Failure
Chronic illnesses, such as kidney disease, liver failure, or pancreatitis, often cause a dog to stop eating and appear sick.
In these cases, you might also notice vomiting, increased thirst, frequent urination, jaundice (yellow gums or eyes), or abdominal pain.
A dog not eating for several days along with such symptoms needs prompt testing to assess organ function and determine the right treatment plan.
7. Medication Side Effects
Sometimes, the reason your dog is not eating and seems sick lies in their medication.
Drugs prescribed for pain, infections, or chronic conditions may upset your dog’s stomach, suppress appetite, or cause nausea.
If the symptoms started shortly after starting a new medication, speak with your vet about alternatives or ways to manage side effects.
8. Pain and Discomfort
Pain from injuries, arthritis, or internal conditions may make your dog too uncomfortable to eat.
If your dog is limping, whimpering, or unusually withdrawn in addition to not eating, pain could be the underlying cause.
Your vet may perform imaging tests or physical exams to locate and diagnose the pain source.
9. Cancer or Tumors
In older dogs, cancer may cause unexplained weight loss, vomiting, and a lack of appetite.
Tumors—whether internal or external—can affect a dog’s metabolism or cause discomfort, resulting in your dog not eating and sick behavior.
Although cancer is a more serious cause, early detection and treatment can make a difference in outcome and quality of life.
Related: Dog shaking and not eating (Explained)
What to Do When Your Dog Is Not Eating and Acting Sick
Step 1: Observe and Monitor
Note when your dog stopped eating, any changes in behavior, and if there are accompanying symptoms like vomiting, diarrhea, or lethargy.
This information will help your veterinarian diagnose the issue more accurately.
Step 2: Offer Bland Food
If your dog refuses regular food but shows mild symptoms, try offering boiled chicken and rice or plain canned pumpkin.
These bland foods are easier on the stomach.
However, if your dog refuses even bland food for more than 24 hours or has other concerning symptoms, don’t delay seeking veterinary help.
Step 3: Check for Dehydration
Dogs not eating and sick often become dehydrated.
Gently pinch the skin on your dog’s back—if it doesn’t snap back quickly, your dog might be dehydrated.
Check the gums too; dry, pale, or sticky gums are red flags.
Provide access to fresh water, but if your dog refuses to drink or can’t keep water down, call your vet immediately.
Step 4: Visit the Veterinarian
If your dog is not eating and continues to show signs of illness, prompt veterinary care is crucial.
Your vet may recommend:
Blood tests
X-rays or ultrasound
Fecal analysis
Urinalysis
Intravenous fluids
Treatment may involve anti-nausea medication, antibiotics, pain management, or hospitalization depending on the cause.
When to Seek Emergency Help
Seek immediate veterinary attention if your dog not eating and sick behavior includes:
Vomiting blood or having bloody diarrhea
Severe lethargy or collapse
Labored breathing
Seizures or tremors
Inability to stand or walk
Bloated abdomen
No water intake for more than 12 hours
Young puppies, senior dogs, or dogs with pre-existing health conditions are particularly vulnerable and should be seen sooner rather than later.
Final Thoughts: Dog Not Eating and Sick
When your dog is not eating and appears sick, it’s more than just a picky mood—it’s a sign that something deeper may be going on.
From minor issues like upset stomachs to more serious concerns like infection or organ failure, the causes vary, but they should never be ignored.
Addressing the issue early by observing your dog’s symptoms and consulting your vet can prevent complications and get your furry friend on the road to recovery.
Always trust your instincts—if your dog’s behavior seems off, it’s best to err on the side of caution.
By understanding the reasons why a dog is not eating and sick, you’ll be better prepared to act quickly and ensure your dog stays healthy and happy.