Seeing anything abnormal in your dog’s stool can be very stressful for you as a dog owner – even if the dog doesn’t seem to be in any distress. It’s important to remember that the colon is lined with mucus in order to keep everything moving smoothly and so, finding a little bit of mucus in dog stool is sometimes normal. However if you continue to see mucus, or you notice that there’s a lot of it, be sure to visit your vet so they can assess the situation.

Possible Causes of Mucus in Dog Stool

There are many reasons why your dog may have a bit (or a lot) of mucus in their stool and it’s not going to go away until you have figured out why.

Here’s a list of possible causes:

• An upset stomach from eating bad food
• Colitis (inflammation of the colon)
• Internal parasites such as roundworm or hookworm
• A viral infection such as parvovirus
• Bacterial infections
• A foreign body in the intestine
• Cancer
• Allergies
• Autoimmune disorders such as inflammatory bowel disease

Unfortunately mucus in the stool won’t tell you what’s wrong, and even knowing the possible causes still won’t tell you what’s wrong. For this reason, if your dog ever has mucus in the stool, it’s important to collect a fresh stool sample and take both your dog and the sample to the vet. If the dog is lethargic, has no appetite and won’t take water, do not wait to collect the sample – get your dog to the vet right away.

Diagnosing Mucus in Dog Stool

Because there are so many possible causes, diagnosing why a dog has mucus in their stool can be difficult. The vet will likely start with a thorough physical examination, looking for signs of illness or tenderness anywhere on the body. While performing the exam, the vet will also check the dog for general signs of sickness.

Once the physical exam has been completed, diagnosing will largely consist of eliminating possible causes to fully understand why your dog has mucus in their stool. Because mucus in the stool can be a result of something as simple as diet, the vet will start by asking you about what the dog has eaten over the past day or so. If nothing abnormal is found, they’ll move on to actual tests to determine the reason for the mucus.

These might include:

• A fecal flotation. This test allows the vet to take a stool sample from the dog and study it for intestinal parasites that might be living within your dog’s intestinal tract. While the parasites cannot be seen, they do lay tiny microscopic eggs that, when observed under a microscope, your vet can see and make a diagnosis of internal parasites causing the mucus.
• Radiographs. These will allow the vet to examine the colon and intestinal tract to see if there’s any irritation of the colon that could be causing the mucus. If the vet sees anything that warrants more testing of the colon, they may also order a colonoscopy or an ultrasound to further evaluate the colon.
• Lab tests including testing tissue sample or feces. Lab tests will need to be done if your vet suspects the cause of the mucus in the stool is a viral or bacterial infection.
• Blood tests. These will test for a number of different things, including allergies, cancer, and infections that may determine why there is mucus in the stool.
• X-rays. X-rays can be taken for a number of different reasons, both to look for tumors as well as foreign objects that could be causing mucus to appear in the stool.

Your vet may perform one or all of these tests, depending on the results and how quickly they reach a diagnosis.

Treating Mucus in Dog Stool

Treatment for mucus in the stool is very varied, because there are so many different causes of it. Here are a few things your vet may recommend:

• Medication: If parasites were found to be the cause of the mucus, your vet may prescribe medication that will get rid of them, and the mucus.
• Hospitalization: This happens in extreme cases but if the cause of mucus is a viral or bacterial infection, it can be very serious – even life-threatening. Your vet may want to keep the dog for a couple of days to treat the infection, get them on IV fluids to prevent dehydration and malnutrition, and provide antibiotics to prevent secondary infections.
• Surgery: This will most likely only occur if the mucus is due to a foreign body in the system. If a tumor is found, the vet will also likely want to perform a biopsy.
• Change in diet: If the cause of the mucus is simply a night of your dog getting into food they shouldn’t have, treatment may be as simple as changing their diet for a few days.

Finding mucus in your dog’s stool can be very worrisome, especially if it’s the first time and you have no idea what’s causing it. While mucus in dog stool often doesn’t indicate anything serious, it’s important to call your vet immediately. They will likely want to see the dog, and a fresh stool sample, right away in order to make a diagnosis and start treatment as soon as possible.