If your dog is clearly feeling unwell and refuses to eat, you’re right to be concerned. Appetite loss is one of the most common symptoms owners notice when their dog is under the weather.
But when a dog is being sick and not eating, it’s more than just a passing issue—it often points to something more serious happening inside the body.
We walk you through what could be going on, offer home care strategies, and explain when it’s time to contact your veterinarian.
Dog Being Sick and Not Eating: Why It Happens
A dog being sick and not eating may be suffering from digestive upset, fever, organ dysfunction, dental disease, viral or bacterial infection, pain, or exposure to toxins.
When a dog feels sick, their body naturally reduces appetite to conserve energy and avoid worsening discomfort, especially in the gut or organs.
Dog Being Sick and Not Eating: Common Causes
1. Gastrointestinal Illness or Upset
One of the most common causes behind a dog being sick and not eating is GI distress. Vomiting, diarrhea, nausea, or bloating are signs your dog’s stomach or intestines aren’t functioning properly. This could be due to:
Eating something they shouldn’t (spoiled food, grass, garbage)
A sudden diet change or food intolerance
Parasites (like roundworms or giardia)
Infections like parvovirus or bacterial overgrowth
When a dog has GI issues, they often associate food with discomfort and may avoid eating altogether. You may notice lip licking, drooling, vomiting bile, or lying in a prayer position if the stomach is sore.
Related: Dog vomiting and not eating (Causes and when to worry)
2. Fever or Infection
If your dog has a fever, their energy will dip and their appetite may vanish. Fever is typically the result of an immune response to infection. Common culprits include:
Upper respiratory infections (coughing, nasal discharge, sneezing)
Tick-borne illnesses (like Lyme or Ehrlichia)
Urinary tract infections (straining to urinate, accidents)
Skin infections or abscesses
Dogs with fever may feel hot to the touch (especially their ears or paws), pant excessively, shiver, or appear generally “off.” Refusing food is often the first clue something isn’t right.
3. Liver or Kidney Disease
Organ dysfunction, especially in the liver or kidneys, often causes nausea, toxin buildup, fatigue, and poor appetite. These chronic illnesses are especially common in older dogs but can also appear in younger pets with congenital issues or toxin exposure.
Kidney disease often presents with:
Increased thirst and urination
Vomiting and weight loss
Bad breath (ammonia-like odor)
Liver disease signs include:
Yellowing of the gums or eyes (jaundice)
Lethargy and disinterest in food
Swollen belly or fluid accumulation
If your dog is sick and not eating, especially with other subtle signs, it’s wise to check for internal organ issues.
4. Dental Problems or Oral Pain
Tooth pain, gum infections, broken teeth, or oral tumors can make eating a painful experience. Dogs may still show interest in food but back away once they try to chew. Drooling, pawing at the mouth, chewing only on one side, or bad breath are all clues.
In senior dogs, periodontal disease is one of the most overlooked reasons they stop eating or suddenly start dropping food from their mouth. Even younger dogs can suffer from cracked teeth or abscesses after chewing on hard toys or bones.
5. Pain or Injury
Pain—especially internal—can make a dog avoid food. Whether it’s from arthritis, an injury, spinal issues, or abdominal discomfort, pain alters behavior.
Your dog might seem restless, unwilling to lie down, or might isolate themselves. Common pain-related signs include:
Whimpering or growling when touched
Changes in posture (arched back, stiff walking)
Licking or guarding a specific area
Pain can suppress appetite significantly, especially if the discomfort worsens with movement (like reaching for the food bowl).
6. Toxin Ingestion
If your dog has eaten something toxic—such as human medication, household cleaners, chocolate, xylitol (from sugar-free gum), or poisonous plants—they may begin vomiting, drooling, shaking, or become disoriented.
Refusal to eat is often one of the first signs after exposure.
Toxin ingestion can be life-threatening, especially if it causes liver failure, neurological damage, or internal bleeding.
If your dog is being sick and not eating and you suspect poisoning, seek immediate emergency care.
What to Do If Your Dog Is Being Sick and Not Eating
If your dog has just started acting sick and hasn’t eaten for a few hours, monitor closely and try these steps:
Offer bland food like plain boiled chicken and white rice in small amounts.
Tempt with broth or wet food if they seem mildly interested but hesitant.
Check for dehydration by gently lifting the skin at the neck—if it doesn’t snap back, hydration is low.
Keep them calm and comfortable in a quiet resting area.
Avoid giving human medications, which may worsen the issue.
If your dog vomits more than twice, has diarrhea for more than 24 hours, or shows signs of pain or lethargy, don’t wait—call your vet.
When to Call or Visit Your Vet
You should contact your vet right away if:
Your dog hasn’t eaten for over 24 hours
Vomiting or diarrhea persists for more than a day
Your dog is lethargic, weak, or showing signs of collapse
You see blood in vomit, stool, or urine
Their abdomen appears swollen or painful to touch
They show signs of dehydration or pale gums
You suspect they ate something toxic
Your vet may perform blood tests, imaging (like X-rays or ultrasound), or a fecal exam to determine what’s going on.
Early treatment is often the key to preventing more serious complications.
Key Takeaway
A dog being sick and not eating is a sign that something inside isn’t right.
While occasional skipped meals aren’t always alarming, when paired with obvious illness, vomiting, or behavioral changes, it’s time to act.
Trust your instincts—dogs are often subtle in how they show pain or discomfort, and refusing food is their way of saying they need help.
Monitoring symptoms early and contacting your veterinarian when necessary can make all the difference in helping your dog recover quickly and comfortably.