Seeing your dog not eating but not losing weight can be both puzzling and concerning.
Unlike typical scenarios where a decrease in food intake results in visible weight loss, some dogs maintain their body weight despite changes in appetite.
We outline the reasons why a dog might not be eating but still not losing weight. We’ll also help you understand when to seek help and what steps you can take to ensure your dog remains healthy.
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Here’s Why Your Dog Has Bloody Diarrhea and Not Eating
When a dog has bloody diarrhea and is not eating, it often signals a serious underlying health issue that requires prompt attention. This combination of symptoms can be caused by gastrointestinal infections, ingestion of toxins, inflammatory bowel disease, pancreatitis, or internal injuries. Bloody diarrhea indicates irritation or bleeding within the intestines, while a loss of appetite (anorexia) suggests the dog is in pain, nauseous, or systemically unwell.
These symptoms together may also point to a more severe condition like hemorrhagic gastroenteritis (HGE), parvovirus (especially in puppies), or even gastrointestinal blockages.
Dog has bloody diarrhea and not eating: Common causes
1. Gastrointestinal Infections
One of the leading reasons a dog has bloody diarrhea and is not eating is a gastrointestinal (GI) infection.
These can be caused by:
Bacteria such as Salmonella, Clostridium, or E. coli
Viruses, including parvovirus or coronavirus
Parasites like hookworms, whipworms, or giardia
These pathogens inflame the intestinal lining, leading to blood in the stool.
In response to discomfort or nausea, your dog may refuse food altogether. Puppies and unvaccinated dogs are especially at risk.
Signs to look for:
Sudden onset of foul-smelling, bloody diarrhea
Vomiting
Lethargy
Fever
If your dog has bloody diarrhea and won’t eat, and shows these symptoms, it’s time to call the vet.
2. Dietary Indiscretion or Food Intolerance
Dogs are notorious for eating things they shouldn’t—from garbage to table scraps.
Dietary indiscretion or a sudden change in food can irritate the gut, causing inflammation and bleeding.
Some dogs also have food allergies or intolerances, which may cause bloody diarrhea over time.
A dog with an upset stomach may avoid food, especially if eating has caused discomfort.
If your dog has bloody diarrhea and not eating after a diet change or ingesting something unfamiliar, this could be the cause.
Always introduce new foods slowly and monitor your dog for adverse reactions.
Related: Dog diarrhea and drooling (Explained)
3. Toxins or Poisoning
When a dog has bloody diarrhea and is not eating, toxic ingestion must be ruled out immediately.
Substances that can cause this include:
Rodenticides (rat poison)
Insecticides
Toxic plants
Certain human medications (e.g., NSAIDs like ibuprofen)
Spoiled or moldy food
These substances can cause internal bleeding, organ failure, and severe GI upset.
Bloody diarrhea and refusal to eat are often early signs of poisoning.
Immediate veterinary attention can be life-saving in these cases.
Additional signs of poisoning may include:
Excessive drooling
Tremors or seizures
Pale gums
Collapse
4. Hemorrhagic Gastroenteritis (HGE)
HGE is a condition characterized by sudden, severe bloody diarrhea (often with a jelly-like consistency) and vomiting.
Dogs with HGE may seem fine one minute and extremely ill the next. Loss of appetite is almost always present.
The exact cause of HGE is unknown, though it’s thought to be linked to bacterial toxins or stress.
Small breeds, such as Miniature Schnauzers and Toy Poodles, are more susceptible.
If your dog has bloody diarrhea and won’t eat and is also lethargic, get them to the vet immediately—HGE can lead to life-threatening dehydration within hours.
5. Intestinal Blockages or Foreign Objects
If your dog swallowed a toy, bone, sock, or any non-digestible object, it could get stuck in the GI tract, causing irritation, bleeding, and blockage.
This often results in bloody diarrhea and vomiting, and your dog will likely refuse food due to nausea or discomfort.
Dogs with blockages may also strain during bowel movements, pace, or cry in pain.
If your dog has bloody diarrhea and not eating and has a history of chewing on household objects, this could be the issue.
Diagnosis typically requires x-rays and possibly surgery to remove the obstruction.
6. Inflammatory Bowel Disease (IBD)
Chronic inflammation in the gut, or inflammatory bowel disease, can cause intermittent bloody diarrhea and loss of appetite.
IBD in dogs is often linked to genetics, immune responses, or food sensitivities.
Dogs with IBD may show the following:
Weight loss
Frequent or recurring bloody stools
Vomiting
Picky or reduced eating behavior
This is a long-term condition that often requires diet modification, medication, and regular monitoring.
Related: Dog diarrhea and drooling (Explained)
7. Cancer of the Gastrointestinal Tract
While less common, cancer can be a reason why a dog has bloody diarrhea and not eating, especially in older dogs.
Tumors in the intestines or stomach can cause internal bleeding and reduce appetite.
Accompanying signs might include:
Black, tarry stools (melena)
Lethargy
Weight loss
Pale gums
A diagnosis will usually involve blood tests, imaging, and possibly a biopsy.
8. Stress or Anxiety
Just like in people, dogs can suffer from stress-related GI symptoms.
A move, new family member, loud noises, or unfamiliar environments can lead to stress colitis, a condition that results in bloody diarrhea and refusal to eat.
Stress-related symptoms often improve once the dog’s environment returns to normal, but persistent cases may require treatment.
Related: Dog diarrhea and not eating (Explained)
What to Do if Your Dog Has Bloody Diarrhea and Is Not Eating
Seeing your dog pass bloody stools and refuse food can be alarming. Here’s how to handle the situation:
Monitor symptoms
Track when the diarrhea started, what it looks like (bright red or dark), and how often it occurs.
Note whether your dog is drinking water, vomiting, or acting lethargic.
Withhold food (briefly)
You can withhold food for 12–24 hours (but not water) to give your dog’s gut a chance to rest.
Do not fast puppies or senior dogs unless advised by a vet.
Offer a bland diet
After the fasting period, introduce a bland diet like boiled chicken and plain white rice for a few days before slowly transitioning back to regular food.
Keep your dog hydrated
Bloody diarrhea can lead to rapid dehydration.
Make sure your dog has constant access to clean water.
If your dog isn’t drinking, seek vet help immediately.
When to See the Vet
While occasional loose stools may not be urgent, bloody diarrhea and loss of appetite is a medical emergency.
Seek immediate veterinary attention if:
Diarrhea is profuse or contains large amounts of blood
Your dog is lethargic or unresponsive
Vomiting accompanies the diarrhea
Your dog hasn’t eaten in over 24 hours
Signs of dehydration are present (sunken eyes, dry gums, loss of skin elasticity)
You suspect your dog ingested something toxic
Key Takeaways: Dog Has Bloody Diarrhea and Not Eating
Bloody diarrhea and not eating in dogs is a serious red flag and often indicates infection, poisoning, GI disease, or stress.
Common causes include GI infections, toxins, foreign objects, HGE, and chronic illness like IBD or cancer.
Immediate veterinary care is crucial, especially if the symptoms persist, worsen, or are accompanied by vomiting or lethargy.
At home care should focus on hydration and possibly offering a bland diet—under guidance from your vet.
Your dog’s health depends on timely intervention.
If your dog has bloody diarrhea and not eating, don’t wait—consult your veterinarian promptly to get to the root of the problem and start treatment.