Watching your dog nibble on grass might seem like a harmless or quirky habit, but when it’s followed by bloody stools, concern quickly sets in.
While grass-eating is often dismissed as normal canine behavior, it can sometimes hint at underlying issues.
We dive into the possible link between grass consumption and bloody stools in dogs—what’s normal, what’s not, and when you should seek veterinary care.
Table of Contents
Can Dog Eating Grass Cause Bloody Stools?
Yes, eating grass can potentially cause bloody stools in dogs, but it’s not always the direct cause. When dogs eat large amounts of grass, especially rough or chemically treated grass, it can irritate the stomach or intestines, leading to inflammation or minor injuries that result in bloody stools.
However, bloody stool may also signal more serious underlying issues like parasites, gastrointestinal disease, or toxins—conditions that may cause both grass-eating and bleeding.
Here’s Why Dogs Eat Grass
Before diving into whether dog eating grass can cause bloody stools, it’s important to understand why dogs eat grass in the first place.
Many dogs eat grass occasionally, and this behavior is generally considered normal. Some common reasons dogs eat grass include:
Natural instinct: Wild ancestors of dogs consumed plant matter occasionally as part of their diet.
Digestive aid: Grass can help stimulate digestion or induce vomiting if a dog feels nauseous.
Nutritional needs: Some dogs might eat grass to supplement fiber or certain nutrients missing in their diet.
Boredom or anxiety: Dogs left alone or under stress may chew on grass as a coping mechanism.
While grass eating itself is usually harmless, the bigger question is whether this behavior can lead to digestive issues like bloody stools.
What Causes Bloody Stools in Dogs?
Bloody stools in dogs, also called hematochezia or melena depending on the blood’s appearance, can be alarming.
Blood in your dog’s stool is never normal and suggests irritation or damage somewhere in the gastrointestinal (GI) tract.
Common causes of bloody stools in dogs include:
Dietary indiscretion: Eating spoiled food, garbage, or sharp objects can injure the GI tract.
Parasitic infections: Intestinal parasites like hookworms, whipworms, and giardia can cause intestinal bleeding.
Bacterial or viral infections: Some infections inflame or damage the intestines, resulting in blood in stool.
Inflammatory bowel disease (IBD): Chronic inflammation in the intestines can cause bleeding.
Food allergies or intolerance: Allergic reactions may cause GI inflammation and bloody stools.
Toxin ingestion: Eating poisonous plants, chemicals, or toxic substances can harm the digestive tract.
Trauma: Physical injury to the abdomen or intestines may result in bloody stools.
Tumors or polyps: Growths in the GI tract can bleed, causing blood in stool.
Anal gland problems: Inflammation or abscesses of the anal glands may lead to blood near stool.
How Eating Grass Cause Bloody Stools In Dogs
1. Grass May Irritate the Digestive Tract
Some types of grass, especially those with sharp edges or rough texture, can irritate a dog’s throat, stomach, or intestines.
If your dog consumes large quantities of such grass, this irritation may lead to mild inflammation or minor bleeding, which could show as blood in the stool.
Related: Dog eating grass and not eating (Here’s why)
2. Grass May Carry Pesticides or Toxins
Grass found in lawns or public parks might be treated with pesticides, herbicides, or fertilizers.
Ingesting grass contaminated with these chemicals can cause GI upset, inflammation, or even poisoning, all of which may lead to bloody stools.
3. Grass Eating May Signal Digestive Upset
Sometimes dogs eat grass to soothe nausea or an upset stomach caused by infections, parasites, or other GI diseases that themselves cause bloody stools.
In this case, the grass eating is a symptom, not the cause, of bloody stools.
4. Foreign Objects Hidden in Grass
Grass can hide burrs, sticks, or other sharp debris that your dog might swallow unintentionally.
These objects can injure the intestines, leading to bleeding and bloody stools.
5. Allergic Reactions to Grass
Although rare, some dogs may have allergies to certain types of grasses or plants, causing inflammation in the GI tract and resulting in bloody stools.
Related: Dog eating grass but not food (Here’s why)
When to Be Concerned
While occasional grass eating followed by mild diarrhea or no symptoms is typically harmless, you should seek veterinary care immediately if you notice:
Bright red blood in stool: This indicates bleeding in the lower GI tract (colon or rectum).
Dark, tarry stools: Suggests bleeding higher up in the digestive system (stomach or small intestines).
Persistent diarrhea or vomiting: Could indicate a serious GI problem.
Lethargy or weakness: Signs your dog may be dehydrated or anemic.
Loss of appetite: Indicates underlying illness.
Abdominal pain or bloating: Suggests GI distress or obstruction.
Pale gums: Sign of blood loss or anemia.
Signs of poisoning: Excessive drooling, seizures, or tremors after eating grass.
What to Do If Your Dog Has Bloody Stools
If your dog is experiencing bloody stools, here’s what you can do:
1. Monitor Closely
Keep an eye on your dog’s stool consistency, color, and frequency.
Note any additional symptoms such as vomiting, lethargy, or changes in appetite.
2. Stop Grass Access Temporarily
Prevent your dog from eating grass for a few days and observe whether the bloody stools improve.
This can help identify if grass is contributing.
3. Check Your Dog’s Diet
Evaluate your dog’s diet for any recent changes or possible ingestion of spoiled food or foreign objects.
4. Hydrate Your Dog
Bloody stools can lead to dehydration.
Make sure your dog has constant access to fresh water.
5. Contact Your Veterinarian
If bloody stools persist for more than 24 hours, or if other concerning symptoms appear, consult your vet immediately.
Blood in stool can indicate serious health issues needing prompt diagnosis and treatment.
Veterinary Diagnosis and Treatment for Bloody Stools
When you visit your vet, they will likely perform:
Physical examination: To check overall health and abdominal tenderness.
Fecal testing: To check for parasites, bacteria, or blood.
Blood tests: To assess organ function and detect infection or anemia.
Imaging: X-rays or ultrasound to identify foreign objects or tumors.
Endoscopy: For direct visualization of the GI tract if needed.
Treatment depends on the underlying cause but may include:
Deworming medication if parasites are detected.
Antibiotics for bacterial infections.
Dietary changes or hypoallergenic diets for food allergies.
Medication to reduce inflammation or control symptoms.
Fluid therapy to treat dehydration.
Surgery if foreign objects or tumors are present.
Supportive care for poisoning or toxin ingestion.
Preventing Bloody Stools Related to Grass Eating
Although grass eating alone is not typically harmful, these tips can help reduce the risk of bloody stools or other complications:
Supervise your dog outdoors to prevent them from eating harmful grass or plants.
Avoid areas treated with pesticides or fertilizers.
Provide a balanced, fiber-rich diet to reduce the urge to eat grass.
Keep your dog’s vaccinations and parasite control up to date.
Regular vet checkups can detect GI problems early.
Provide mental and physical stimulation to reduce stress-related grass eating.
Key Takeaway
In summary, dog eating grass itself does not usually cause bloody stools, but it can contribute indirectly through irritation, toxin ingestion, or foreign body injuries.
More often, bloody stools indicate an underlying gastrointestinal issue, such as infections, parasites, allergies, or diseases, which may also cause a dog to eat grass as a coping mechanism.
If your dog’s stools contain blood after eating grass, or if you notice any other symptoms like vomiting, lethargy, or loss of appetite, it’s crucial to consult your veterinarian promptly.
Early diagnosis and treatment are vital to ensure your dog stays healthy and comfortable.