Seeing your dog pass blood and refuse food is an alarming and distressing experience for any pet owner. These symptoms often point to significant underlying health issues that shouldn’t be ignored.
We outline the common causes of dog passing blood and not eating, what you can do at home, and when to seek veterinary help.
Dog Passing Blood and Not Eating — Why It Happens
When a dog is passing blood and not eating, it usually signals a serious problem with their gastrointestinal or systemic health. The most likely causes include gastrointestinal infections, parasites, hemorrhagic gastroenteritis, trauma, poisoning, or more chronic conditions like cancer.
In some cases, the blood may appear in the stool or urine, each pointing to different issues.
The refusal to eat adds further concern, suggesting pain, nausea, or systemic illness. Early intervention is critical.
Common Causes of Dog Passing Blood and Not Eating
Hemorrhagic Gastroenteritis (HGE)
HGE is a potentially life-threatening condition that causes sudden vomiting and bloody diarrhea.
Dogs suffering from HGE often stop eating and appear weak or lethargic. The blood in the stool is usually bright red or sometimes resembles raspberry jam.
While the exact cause of HGE is unknown, it is suspected to involve bacterial infections, dietary indiscretion, or stress. Immediate veterinary care is essential to prevent dehydration and shock.
Intestinal Parasites
Hookworms, whipworms, and other intestinal parasites can cause bloody stools and loss of appetite.
These parasites irritate the gastrointestinal lining, leading to bleeding and nutrient malabsorption.
Puppies and immunocompromised dogs are especially at risk, and you may also notice weight loss, vomiting, or a pot-bellied appearance.
Regular deworming and fecal exams help prevent parasite-related complications.
Gastrointestinal Ulcers
Stomach or intestinal ulcers can result from chronic stress, certain medications (like NSAIDs), or underlying conditions such as liver disease.
These ulcers may cause a dog to pass dark, tarry blood (melena) and stop eating due to pain or nausea.
Additional symptoms may include vomiting, weakness, and restlessness. Ulcers can worsen quickly without treatment, so a vet visit is crucial if this is suspected.
Read more: Dog Vomiting and Not Eating (What it means and how to help)
Trauma or Ingestion of Foreign Objects
If your dog has eaten a sharp object, it may cause internal bleeding in the gastrointestinal tract.
Dogs with this issue may strain to defecate, pass blood, and become withdrawn or refuse food.
This situation is an emergency. Foreign bodies can perforate the intestinal lining, leading to peritonitis or sepsis, both of which are life-threatening.
Poisoning or Toxin Exposure
Rat poison, certain plants, and human medications can cause internal bleeding and gastrointestinal distress.
Affected dogs may vomit, have bloody diarrhea, tremble, collapse, or refuse to eat.
Poisoning requires immediate medical attention, especially since internal bleeding can progress rapidly without obvious external signs.
Cancer or Tumors in the Digestive Tract
In older dogs, cancer in the stomach, intestines, or rectum may cause blood in the stool and anorexia.
These conditions typically present gradually, with additional signs such as weight loss, fatigue, or bloating.
Early detection through imaging and biopsies is essential for determining treatment options and prognosis.
What to Do If Your Dog Is Passing Blood and Not Eating
First, try to keep your dog calm and restrict access to food until a vet advises otherwise.
If you see bright red blood in the stool or vomit, take a photo or bring a sample to the vet to aid diagnosis.
Ensure your dog stays hydrated. Offer small amounts of water or ice cubes, but avoid forcing fluids if your dog is vomiting.
You can check your dog’s gums – if they are pale, dry, or tacky, it may indicate dehydration or internal blood loss.
Do not administer over-the-counter medications, as these could worsen bleeding or mask important symptoms.
When to Call or Visit Your Vet
Contact your veterinarian immediately if you notice any of the following:
Bright red blood in your dog’s stool or vomit
Black, tarry stools (indicating digested blood)
Complete refusal to eat for more than 24 hours
Lethargy, collapse, or signs of shock
Vomiting combined with blood in stool or urine
Pale gums, rapid breathing, or signs of pain
These symptoms indicate a potentially life-threatening emergency that should not wait.
Read more: Dog Diarrhea and Not Eating (Is it serious or just an upset stomach?)
Key Takeaway
When a dog is passing blood and not eating, it’s a red flag for serious internal issues, often requiring emergency care.
Whether it’s an infection, trauma, poisoning, or chronic disease, early intervention can significantly improve outcomes.
Stay calm, document symptoms, and contact your veterinarian right away. Your quick action could save your dog’s life.