My Dog Has Bloody Diarrhea and Is Shaking (Here’s Why)

Dog Bloody Diarrhea and Shaking: Common Causes 

1. Hemorrhagic Gastroenteritis (HGE)

Hemorrhagic gastroenteritis is one of the most common causes when a dog has bloody diarrhea and is shaking.

This condition causes sudden and severe inflammation of the gastrointestinal tract, leading to bloody, jelly-like diarrhea and signs of physical distress.

Shaking occurs because the dog may be experiencing pain or fever.

HGE can rapidly lead to dehydration, which adds to the weakness and trembling. Without fast treatment, HGE can be fatal.

Related: Dog diarrhea shaking and panting (What it means)

2. Ingestion of Toxins or Poison

If your dog is shaking and has bloody diarrhea, poisoning should be high on your list of suspicions. Dogs often ingest toxic substances such as:

• Household cleaners

• Rat poison

• Human medications (especially NSAIDs)

• Toxic foods like chocolate or grapes

These toxins can damage the gastrointestinal lining, leading to bloody stool, vomiting, and shaking due to toxic effects on the nervous system or organs.

Poisoning usually progresses quickly and requires emergency care.

3. Severe Gastrointestinal Infection

A bacterial, viral, or parasitic infection in the gut may lead to bloody diarrhea and shaking in dogs. Infections such as:

• Parvovirus (especially in puppies)

• Salmonella

• Giardia

• Campylobacter

can irritate and inflame the intestinal lining, causing visible blood in the stool.

As the infection spreads, your dog may begin shaking from fever, weakness, or abdominal pain.

Dogs with weaker immune systems (such as puppies or elderly dogs) are especially vulnerable to these infections and may deteriorate fast.

4. Pancreatitis

Pancreatitis is the inflammation of the pancreas and is another possible explanation if your dog has bloody diarrhea and is shaking.

t’s often triggered by fatty food, but can also be associated with medication or underlying disease.

This condition can cause:

• Bloody or greasy diarrhea

• Vomiting

• Abdominal pain (causing shaking)

• Loss of appetite

• Fever

Dogs suffering from pancreatitis often tremble or hunch over due to pain and discomfort.

Related: Puppy diarrhea and shaking (What it means)

5. Parvovirus (Parvo)

If your puppy has bloody diarrhea and is shaking, canine parvovirus could be the cause.

Parvo is an extremely contagious and often deadly viral disease, especially common in unvaccinated puppies.

Common signs of parvo include:

• Bloody, foul-smelling diarrhea

• Vomiting

• Extreme weakness

• Fever

• Shaking and lethargy

Parvo requires urgent medical attention and intensive care to prevent fatal outcomes.

6. Intestinal Blockage or Foreign Object

Dogs are known for eating things they shouldn’t. If a foreign object becomes lodged in the intestines, it can tear or block the gastrointestinal tract, leading to bloody diarrhea.

The discomfort may also cause your dog to shake or tremble.

Other signs include:

• Straining to poop

• Vomiting

• Refusing food

• Bloated or painful abdomen

This is a medical emergency that usually requires surgery.

7. Severe Food Intolerance or Allergy

Sudden exposure to a new food or ingredient your dog is allergic to may cause bloody diarrhea, vomiting, and shaking due to stomach pain or stress.

While not always life-threatening, this scenario still requires attention to prevent complications such as dehydration.

Related: Dog diarrhea and shaking (What it means)

8. Stress or Anxiety

Though not as dangerous as some other causes, stress and anxiety can lead to physical reactions like diarrhea and shaking in dogs.

However, it’s rare for stress alone to cause bloody diarrhea, unless combined with other health issues or if the dog has a sensitive stomach.

Stress-induced shaking and diarrhea may happen after:

• A move or travel

• Loud noises (like fireworks)

• New pets or strangers in the home

• Vet visits

If the blood in the stool is minor and related to straining or irritation, reducing stress and monitoring symptoms may be enough—but always consult your vet to rule out deeper issues.

9. Side Effects of Medication

Some medications can irritate your dog’s stomach or cause adverse effects, especially:

• NSAIDs (Nonsteroidal anti-inflammatory drugs)

• Antibiotics

• Steroids

• Chemotherapy drugs

These medications can lead to bloody diarrhea and shaking if your dog is reacting poorly or becoming dehydrated.

What to Do If Your Dog Has Bloody Diarrhea and Is Shaking

1. Seek Immediate Veterinary Attention

If your dog has both bloody diarrhea and is shaking, don’t wait—go to a vet immediately.

These symptoms often signal serious internal problems, dehydration, infection, or poisoning.

Waiting too long can worsen your dog’s condition and reduce chances of recovery.

2. Avoid Home Remedies or Over-the-Counter Meds

Never attempt to treat bloody diarrhea or shaking with human medications like Imodium or Pepto Bismol unless specifically directed by your vet.

These can be toxic or mask symptoms, making diagnosis harder.

3. Keep Your Dog Hydrated

Offer fresh, clean water frequently. Dehydration from bloody diarrhea can escalate quickly, especially in puppies or older dogs.

If your dog refuses water, that’s a red flag that they need IV fluids at the vet.

4. Prepare a Symptom History for the Vet

Before heading to the vet, gather helpful info such as:

• When symptoms began

• Color and consistency of the diarrhea

• Any recent dietary changes

• Possible exposure to toxins

• Medications given recently

• Vaccination status

This helps the vet diagnose the root cause faster.

When to Worry: Red Flags Requiring Emergency Care

These signs alongside bloody diarrhea and shaking should prompt you to go to the emergency vet ASAP:

• Vomiting blood or foam

• Lethargy or unresponsiveness

• Pale or cold gums

• Abdominal bloating or pain

• Refusal to drink or eat

• Collapse or seizures

• Rapid breathing or heart rate

Key Takeaway

Bloody diarrhea and  shaking are symptoms are almost always signs of a bigger health problem that needs prompt veterinary attention.

While not every cause is fatal, ignoring the signs can lead to serious complications like severe dehydration, internal bleeding, or even organ failure.

The earlier you identify and treat the cause, the better your dog’s chances of recovery.

Whether it’s a gastrointestinal infection, poisoning, or stress, a vet will be able to run the right tests, provide supportive care, and guide you on how to help your pup bounce back.