About the Causes of Large Amounts of Yellow Mucus in Stool

By Lisa McQuerrey

Yellow mucus in your dog’s stool could be a sign of infection, parasites, obstruction, an allergen or diet change. Any time your dog has abnormal stool for more than a day or two, it’s time to see your vet for an evaluation -- puppies should be seen right away. Take a stool sample with you to speed the diagnostic process.

Intestinal Infection

A light covering of clear mucus on your dog’s stool is not usually a sign for concern. Mucus coats the intestinal walls to help the bowel evacuation process. A large amount of yellow mucus, however, can be a sign of intestinal infection. Your dog may have colitis, an irritated bowel or an inflammation of the gastrointestinal tract. Consult your vet for an evaluation. In addition to examining your dog’s stool, he may draw blood, and if an infection is present, treat your dog with antibiotics.

Intestinal Obstruction

If a foreign object is blocking any part of your dog’s intestinal tract, it could create a puncture and lead to infection, presenting as yellow mucus in the stool. Tumors and polyps can lead to blockage as well. Your dog may not be able to empty his bowels and may cry or strain when trying to go to the bathroom. Immediate medical attention is vital to ensure the blockage is removed. Your vet likely will perform X-rays or an ultrasound to identify the problem. Depending on the severity of the blockage, surgical treatment may be advised.

Colitis or Inflamed Colon

The presence of excessive mucus in your dog’s stool can be an indication of colitis or colon inflammation. Your dog may experience diarrhea and fatty, mucus-covered stools. The condition is caused by a variety of issues including stress, bowel disease, food allergies and intestinal parasites. Your vet may use diagnostic tools such as a rectal exam, radiographs or colonoscopy in conjunction with blood and fecal tests to make a diagnosis. Treatment will be based on the cause of the inflammation.

Coronavirus Disease

Coronavirus disease is an intestinal infection; puppies are particularly susceptible to it. A dog gets the disease by coming into contact with other infected dogs. Diarrhea and loose, foul-smelling orange mucus-laced stool is a primary symptom, often accompanied by listlessness and a decreased appetite. The infection can be mixed with parvovirus. Treatment typically consists of rehydration and possibly antibiotics to protect against bacterial infection.