When your dog is experiencing both vomit and diarrhea with mucus, it’s a clear sign that something is wrong with their digestive system.
Vomiting and diarrhea on their own are common in dogs, but the presence of mucus in the stool or even in the vomit signals irritation, inflammation, or infection in the gastrointestinal tract.
Whether it’s something as simple as dietary indiscretion or as serious as a parasitic infection or poisoning, these symptoms should never be ignored.
We outline the common causes behind dog vomit and diarrhea with mucus, what you can do at home, and when it’s time to take your dog to the vet.
Dog vomit and diarrhea with mucus: Why It Happens
Dog vomit and diarrhea with mucus typically occur due to irritation or inflammation of the gastrointestinal tract. This can be caused by infections (bacterial, viral, or parasitic), dietary indiscretion, food allergies, stress, or more serious conditions like poisoning or inflammatory bowel disease.
The mucus is produced as a protective response by the digestive lining, while vomiting and diarrhea are the body’s way of expelling irritants or harmful substances.
When these symptoms appear together, it usually signals an underlying issue that needs prompt attention.
Common Causes of Dog Vomit and Diarrhea with Mucus
Gastrointestinal infections
The most common cause of vomiting and diarrhea with mucus in dogs is a gastrointestinal infection.
These infections can be caused by bacteria, viruses, or intestinal parasites.
When the digestive tract becomes inflamed due to these invaders, it produces more mucus to protect itself, which shows up in your dog’s vomit or poop.
Pathogens like Giardia, Salmonella, or Parvovirus are notorious for causing dog diarrhea with mucus, often accompanied by vomiting.
These conditions are not only uncomfortable but can also be life-threatening without treatment.
Related: Dog throwing up and not eating (Here’s why)
Dietary indiscretion
Dogs love to explore the world with their mouths.
Eating spoiled food, garbage, table scraps, or even foreign objects can irritate the digestive system, leading to vomiting and diarrhea with mucus.
This condition, often referred to as “garbage gut,” is especially common in curious pups and indiscriminate eaters.
Dietary changes, such as a sudden switch in food, can also cause gastrointestinal upset.
Even introducing a new treat can lead to mucus-filled diarrhea and vomiting.
Food intolerance or allergies
If your dog is allergic or intolerant to certain ingredients in their food, they may develop chronic vomiting and diarrhea with mucus.
Common culprits include beef, dairy, chicken, soy, and wheat.
The immune response to these allergens can inflame the stomach and intestines, resulting in the production of excess mucus.
Dogs with food sensitivities often also show other signs such as itchy skin, ear infections, or paw licking.
Intestinal parasites
Worms such as hookworms, roundworms, and whipworms are a frequent cause of dog poop with mucus and vomiting.
These parasites attach themselves to the intestinal lining and cause damage, leading to inflammation and mucus production.
Puppies are especially prone to parasitic infections, which can become serious quickly due to their small size and underdeveloped immune systems.
Related: Dog throwing up and drinking a lot of water (Here’s why)
Inflammatory bowel disease (IBD)
Dogs suffering from chronic gastrointestinal inflammation—often diagnosed as inflammatory bowel disease—may display symptoms such as dog vomit and diarrhea with mucus over a prolonged period.
IBD causes the intestinal walls to thicken and reduces their ability to absorb nutrients, leading to poor digestion and increased mucus secretion.
IBD is often diagnosed when other causes have been ruled out and typically requires dietary changes and medication for management.
Stress or anxiety
Like humans, dogs can have gastrointestinal reactions to stress.
A move, new pet in the home, loud noises, or changes in routine can trigger vomiting and diarrhea with mucus.
Stress-related episodes are usually short-lived, but chronic anxiety can cause recurring digestive issues.
You may also notice other signs like pacing, whining, excessive licking, or withdrawal.
Poisoning or toxin ingestion
Ingesting toxic substances like household cleaners, certain human foods (like chocolate or grapes), or poisonous plants can cause severe dog vomit and diarrhea with mucus.
This is your dog’s body trying to eliminate the toxin.
In these cases, vomiting and diarrhea may also be accompanied by lethargy, tremors, drooling, and collapse. Time is critical if poisoning is suspected.
Medications and side effects
Certain medications can cause gastrointestinal upset, including antibiotics, NSAIDs, and cancer medications.
These drugs can irritate the stomach lining or disrupt the balance of gut bacteria, resulting in mucus-filled vomit and diarrhea.
If your dog recently started a new medication, this could be the cause.
Always talk to your vet before stopping any prescribed medication.
Pancreatitis
Inflammation of the pancreas, or pancreatitis, is a serious condition that can cause vomiting, diarrhea with mucus, abdominal pain, and lethargy.
Pancreatitis is often triggered by a fatty meal and is more common in certain breeds like Miniature Schnauzers and Yorkshire Terriers.
In moderate to severe cases, pancreatitis can be life-threatening, and mucus in the vomit or stool is a red flag that should prompt immediate attention.
Dog vomit and diarrhea with mucus: What to do
When your dog has vomit and diarrhea with mucus, here’s what you can do at home, and when to seek veterinary help:
1. Withhold food temporarily
Give your dog’s digestive system a chance to rest by withholding food for 12–24 hours (only if your dog is an adult and in otherwise good health).
Keep clean water available to avoid dehydration.
Puppies and senior dogs should not fast without veterinary advice.
2. Provide bland food
After the fasting period, offer a bland diet such as boiled chicken and plain white rice in small portions.
This gentle food is easier on the stomach.
Gradually reintroduce your dog’s normal food over several days if symptoms improve.
3. Ensure hydration
Vomiting and diarrhea cause significant fluid loss.
Make sure your dog has constant access to fresh water.
You can also offer electrolyte solutions formulated for dogs to help with rehydration.
4. Monitor behavior
Keep an eye on your dog’s activity level, appetite, and symptoms.
If the vomiting and diarrhea with mucus last more than 24 hours, worsen, or are accompanied by additional signs like blood in stool, collapse, or fever, seek immediate veterinary care.
5. Avoid over-the-counter meds
Never give human medications like Pepto-Bismol or Imodium to your dog without vet approval.
Some human medications can be toxic to dogs, especially in high doses or certain breeds.
When to seek veterinary help
You should contact your veterinarian if:
The vomit and diarrhea with mucus persist beyond 24 hours.
You notice blood in the vomit or stool.
Your dog is lethargic, weak, or refuses to eat or drink.
There’s suspicion of poisoning or ingestion of a foreign object.
Your dog is a puppy, senior, or has an existing health condition.
The symptoms return frequently or seem to be chronic.
Your vet may recommend diagnostic tests such as a fecal exam, bloodwork, ultrasound, or X-ray to determine the cause of the symptoms.
Treatment could involve fluids for dehydration, medication to reduce vomiting or diarrhea, or even hospitalization in serious cases.
Key Takeaway
Experiencing dog vomit and diarrhea with mucus can be distressing for both you and your pet.
While sometimes the cause may be simple and resolve with rest and hydration, persistent or severe symptoms can point to a more serious condition.
Recognizing the signs early, understanding potential causes, and knowing when to seek veterinary help can make all the difference in your dog’s recovery.
Always err on the side of caution and get a professional opinion if you’re unsure.
By providing appropriate care and addressing the root cause of your dog’s discomfort, you help ensure a faster recovery and a healthier, happier companion.