Dog Pooping Blood and Drinking a Lot of Water (Why It Happens)

Dog Pooping Blood and Drinking a Lot of Water: Common Causes 

Gastrointestinal Infections

Bacterial or viral infections can inflame the gut lining, leading to bloody stools. Dogs may develop colitis or hemorrhagic gastroenteritis, which often causes sudden and dramatic bleeding in the stool.

When the body loses fluid through diarrhea or blood loss, your dog will often become dehydrated.

In response, they may start drinking much more water to compensate. Owners may also notice vomiting, lethargy, and loss of appetite alongside the bloody stools.

These infections are serious and can progress quickly, so veterinary care is essential.

Read more: Dog Pooping Blood, Vomiting and Not Eating (Here’s Why)

Kidney Disease

Kidney dysfunction can cause increased thirst and urination as the body loses its ability to filter toxins effectively.

At the same time, toxins that accumulate in the blood can irritate the gastrointestinal tract, sometimes leading to ulcers and bleeding in the stool.

Dogs with kidney disease may also show signs like weight loss, nausea, vomiting, and bad breath.

Because the kidneys play a vital role in maintaining the body’s fluid and electrolyte balance, their decline often manifests in multiple systems, making bloody stools and excessive water drinking a dangerous red flag.

Diabetes Mellitus

In diabetic dogs, the body cannot properly regulate blood sugar levels. One hallmark symptom is polydipsia, or excessive thirst.

Dogs with uncontrolled diabetes may also develop gastrointestinal issues, either due to the disease itself or secondary complications.

Bloody stools can sometimes arise from infections, ulcers, or stress on the digestive system. In some cases, diabetic ketoacidosis (a dangerous complication of diabetes) can also cause severe GI upset, with blood appearing in the stool or vomit.

If your dog is pooping blood and drinking excessively, diabetes should always be considered, especially if other signs like weight loss, increased appetite, or frequent urination are present.

Poisoning or Toxin Ingestion

Ingesting toxins, whether from spoiled food, chemicals, or certain medications, can severely irritate the digestive system, leading to bloody diarrhea.

Some toxins, like rodenticides or antifreeze, can also affect the kidneys and liver, which then causes increased thirst as the body struggles to cope.

Along with blood in the stool and excessive drinking, poisoning often causes sudden illness with vomiting, drooling, tremors, or seizures. Because toxins can be rapidly fatal, this situation is always considered a veterinary emergency.

Cancer

Gastrointestinal cancers, such as tumors in the intestines or colon, can cause chronic bleeding into the stool.

At the same time, cancers affecting the kidneys or endocrine system may trigger increased thirst and urination.

Unfortunately, cancer in dogs is not uncommon, particularly in older pets. Owners may notice additional signs such as weight loss, decreased appetite, weakness, or abdominal swelling.

Blood in the stool combined with unusual drinking habits should always raise concern for more serious underlying disease.

Inflammatory Bowel Disease (IBD)

Chronic inflammation of the digestive tract can lead to bloody stools, diarrhea, and abdominal discomfort.

Dogs with IBD may drink more water than usual, particularly if they are losing fluids through frequent bowel movements.

IBD tends to cause a waxing and waning pattern of symptoms, with periods of relative stability interrupted by flare-ups.

Over time, it can take a toll on a dog’s weight and energy levels. Management usually requires long-term dietary adjustments and sometimes medication.

What to Do If Your Dog Is Pooping Blood and Drinking a Lot of Water

If you notice your dog showing these symptoms, the first step is to stay calm but act quickly.

Ensure your dog has access to fresh, clean water since dehydration can worsen rapidly in these situations. Avoid giving human medications, as many are toxic to dogs and can make the situation worse.

Check for any other symptoms such as vomiting, lethargy, or refusal to eat, and try to note when the changes first started.

Collect a sample of the bloody stool if possible, as your veterinarian may need it for diagnostic testing.

While waiting for veterinary care, do not restrict your dog’s water intake. Excessive drinking is often their body’s way of trying to restore balance. However, avoid offering rich foods or treats that could further upset the digestive system.

When to Call or Visit Your Vet

Any time you see blood in your dog’s stool combined with increased water intake, you should contact your veterinarian promptly. These symptoms are rarely minor and often indicate something serious.

Seek emergency care immediately if your dog is also vomiting blood, unable to stand, collapsing, or showing signs of severe dehydration like dry gums or sunken eyes.

Rapid changes in thirst or urination, especially when paired with bloody diarrhea, warrant urgent attention.

If your dog already has a known condition such as diabetes or kidney disease and develops bloody stools, call your vet without delay, as this could signal complications that need immediate intervention.

Read more: Dog Pooping Blood and Mucus (Here’s why)

Key Takeaway

Dog pooping blood and drinking a lot of water is always a cause for concern and should never be brushed off as something minor.

These signs together suggest that your dog may be facing a serious underlying condition such as infection, kidney disease, diabetes, or poisoning.

Providing fresh water, keeping a stool sample, and seeking prompt veterinary care are the most important steps you can take.

With quick attention, many of these conditions can be managed or treated, giving your dog the best chance for recovery.

Stay alert to changes in your dog’s behavior and health, and trust your instincts — if you feel something is wrong, your veterinarian should be your first call.