Checking your dog’s poop isn’t anyone’s idea of a good time, obviously. But it can give you a clear picture of your pet’s overall health. Mucus in the stool is never normal. If you see it, that could be a sign of a potentially serious problem. Here’s some information on some of the potential issues, and what you, as your dog’s owner, can do to help your canine.

Get To The Vet

Mucus in the stool should be concerning, but it doesn’t necessarily mean you need to panic. It could simply be a sign that your dog is having diarrhea. But it could also be an indication of either a parasite, an infection, or a more serious illness.

The best course of action is to watch your dog closely. If the problem doesn’t go away quickly, then it might be something more than diarrhea. Get a stool sample and take he or she to the vet so that a thorough examination can be performed.

Mucus Dog Stool | Dr MartyIf your dog seems to have no energy and is neither eating nor drinking, get he or she to the vet quickly. Don’t worry about getting a stool sample.1

The vet will perform tests to see whether the issue is irritable bowel syndrome, inflammatory bowel disease, or some other serious problem. The veterinarian will suggest an x-ray if there is any reason to believe your dog might have something lodged in the large intestine.

The Usual Suspects

As you know, there are many potential reasons behind the formation of mucus in a dog’s stool. But some of them are more common than others. Here are a few of the typical culprits:


One of the more common reasons for mucus in the stool is a parasite known as Giardia. This is a one-celled parasite that can affect dogs as well as humans. In fact, it is one of the main causes of traveler’s diarrhea. This is a condition that often affects people who travel to underdeveloped countries and either drink contaminated water or eat undercooked food.

When the Giardia parasite causes diarrhea, this is known as Giardiasis. While it can cause diarrhea in dogs, often times it won’t cause any other symptoms. Once the Giardia organism gets into a dog’s large intestine, it can cause damage to the intestinal wall.2 A dog can pick up the parasite from drinking contaminated water or simply inhaling it through his nose when sniffing the ground.

A dog with Giardiasis will sometimes have foul-smelling diarrhea. If the dog doesn’t have diarrhea, his stool may be covered in mucus and have a greenish tint. It usually takes anywhere from 5-12 days for a dog to eliminate the parasite from his system.3

If your vet thinks your dog might have Giardia, they may be able to detect it by examining a fecal sample. The treatment plan will vary, depending on your dog’s overall condition and the degree of the infection.


Mucus in a dog’s stool can sometimes be due to a condition known as colitis. In a nutshell, this is an inflammation of the colon, or large intestine. In many instances, a dog with colitis will have to defecate often, typically producing small volumes of diarrhea. Straining is also common.

There are many different causes of colitis. These include a Giardia infestation, a bacterial infection, and inflammatory bowel disease.4 However, it can also develop if your dog comes in contact with an infected dog, or if he or she eats contaminated food. It can sometimes occur when your dog is in a damp environment for an extended period of time, too.

No matter the cause, the inflammation makes it difficult for your dog’s system to properly absorb water or store feces. This is one of the reasons why mucus appears in the stool.5

Your vet will perform tests to determine whether your dog has colitis or something else, such as a polyp or tumor in the colon. Potential tests include an enema, abdominal ultrasound, a rectal examination, and blood tests. The course of treatment will depend on the cause of the problem. In many instances, increasing your dog’s fiber intake may help alleviate symptoms.6

Most of the time, the prognosis of a dog with colitis is excellent. Most dogs will return to normal in anywhere from 3-5 days. If your dog has chronic colitis, you will need to keep a close watch on his diet.


Mucus Dog Stool | Dr MartyRoundworms can also lead to mucus in the stool. When a dog is infected, his or her feces will contain roundworm eggs. When another dog either sniffs or licks contaminated feces, he will likely become infected as well. Birds, roaches, and rodents can also spread roundworms.7

Roundworms are typically most serious in puppies. Roundworms will usually live in the large intestine, feeding on the food the dog digests. If the infestation is severe, the worms could rob the puppy of much-needed nutrients. As a result, he or she may experience stunted growth.8

There is a slight risk that roundworms can be passed from a dog to a human. This is one of the reasons why dogs must be checked for worms on a regular basis. Your vet will also be able to recommend ways to prevent worm infestations in the future.

The Bottom Line of Mucus

Again, mucus in the stool is not normal. It needs to be checked out. At the same time, however, you don’t need to automatically fear the worst. There are instances where mucus can be a sign of a serious problem. But the cause can be successfully treated in the vast majority of cases, and your dog will be happy and healthy in no time!

Learn More:
Gurgling Stomach in Dogs: What Does It Mean?
Is Dog Diarrhea a Problem For Your Pooch? DIY Home Remedies
Dog Constipation: Causes and How to Fix It?