Trichobezoars in Dogs

By Catherine Barnette, DVM

Trichobezoar is the medical or scientific term that is used to describe a hairball. The word “trich” means hair, while a bezoar is any foreign material that obstructs the stomach or intestines. Therefore, a trichobezoar is a gastrointestinal obstruction caused by hair. While hairballs are typically attributed to cats, they can also cause problems in dogs. Any dog or cat that grooms themselves, or eats the hair of others, is at risk of developing a trichobezoar.

What causes trichobezoars?

Dogs can ingest hair when grooming themselves, as well as by eating hair that they find in their environment. This hair cannot be digested, due to the presence of keratin (a fibrous, structural protein); therefore, it usually passes through the intestines and leaves the body in the feces. In some situations, however, hair may become tangled on itself or another object within the stomach or intestines. This can result in the tangled mass of hair becoming too large to pass in the feces, resulting in a hairball, or trichobezoar.

Once a hairball forms, there are two possible outcomes. Many dog simply vomit up the hairball, leaving you to discover it on your floor, and continue on with their normal lives. In some cases, however, this hairball may become lodged in the gastrointestinal tract, leading to an obstruction.

Trichobezoars can occur in any dog, but they are more common in dogs with skin conditions. These dogs tend to lick their skin more often and ingest larger amounts of hair.

What are the signs of a trichobezoar?

In many cases, the only sign that your pet has a trichobezoar is a vomited hairball. A dog’s trichobezoar typically has the same cylindrical shape that you may associate with a cat hairball, due to forces that compress the mass of hair as it travels up the esophagus. However, trichobezoars that cause an obstruction are not as easily identified.

"If your dog is unable to keep down food or water, veterinary treatment is needed."

In the event that a trichobezoar is causing an obstruction, you may not see hair in your pet’s vomit. Signs that may indicate an obstruction include vomiting, abdominal pain, and lack of bowel movements. If your dog is unable to keep down food or water, veterinary treatment is needed.

How are trichobezoars diagnosed?

If your dog is vomiting hairballs, the diagnosis is straightforward. Your veterinarian may recommend diagnostics to search for underlying causes of your dog’s hairballs, such as a thorough skin examination, blood tests, and possible gastrointestinal testing.

In the event of an obstruction caused by a trichobezoar, further testing will be needed. Your veterinarian will begin with a thorough physical examination, assessing your dog’s overall health while also palpating the abdomen for any evidence of intestinal disease or an obstruction. Next, your veterinarian will likely recommend imaging, to look for evidence of an obstruction. In most cases, radiographs (x-rays) are the first step in assessing for the presence of an obstruction. Depending on the appearance of your dog’s radiographs, your veterinarian may also recommend other imaging tests, such as a contrast study (which examines the flow of a radiopaque material through the intestines) or an ultrasound.

Your veterinarian may also recommend blood tests, to assess your dog’s organ function and overall health.

What is the treatment for a trichobezoar that is causing an obstruction?

If your dog has an obstruction that is caused by a trichobezoar, it will need to be removed. In rare cases, your veterinarian may recommend removal with an endoscope that can be placed down your dog’s esophagus and into the stomach. More commonly, however, removal is accomplished via surgery. Surgery allows your veterinarian to access your dog’s entire gastrointestinal tract, looking for any potential obstructions and removing trichobezoars at multiple sites, if necessary.

"More commonly...removal is accomplished via surgery."

Most dogs respond well to surgery, as long as it is performed promptly, before significant intestinal damage has occurred. Your veterinarian will talk to you about your dog’s prognosis before surgery, as well as about required follow-up care after surgery. Most patients remain hospitalized for one to three days after surgery and are then sent home with specific instructions regarding diet, medication, and exercise restriction.

Can trichobezoars be prevented?

Trichobezoars in dogs are often related to underlying skin disease. Preventing the recurrence of these trichobezoars will require working closely with your veterinarian to diagnose and manage allergies or other underlying skin conditions.

If your dog’s trichobezoars have another cause, such as ingesting human hair or the hair of other pets in the home, you may need to instead focus on limiting your dog’s access to hair. Making sure that trash cans are kept out of reach and your floor is free of hair can help prevent recurrence.

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