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Key takeaways


Oral masses are abnormal lumps, swellings, or protrusions inside a dog’s mouth.

  • Dogs with oral masses may have difficulty eating or bleed from the mouth
  • Oral masses have a wide variety of causes, including infections, cancers, or traumatic injuries
  • Diagnostics for oral masses include a physical examination, biopsy, cytology, diagnostic imaging, and bloodwork
  • Treatment varies depending on the underlying condition, and may include medication, surgery, or cancer treatment
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A closer look: Oral Masses in Dogs


Masses may develop in the mouth for different reasons. Some masses are harmless but may impede eating if they are large enough to interfere with chewing and swallowing. Others are cancerous and may become life threatening if cancer spreads (metastasizes) to other tissues.

Any new mass in the mouth warrants veterinary attention and monitoring. Masses that grow rapidly and/or appear ulcerated and painful warrant prompt veterinary attention. If oral masses are impeding eating severely enough to cause weight loss or difficulty breathing urgent veterinary care is needed.

Different types of oral masses have different appearances:

  • Smooth pink masses are commonly gingival hyperplasia
  • Black masses may be melanomas
  • Cysts or abscesses are fluid-filled swellings, can grow quite large
  • Benign tumors typically do not change in size significantly, and rarely bleed or become inflamed
  • Malignant tumors often grow rapidly and may be prone to inflammation, bleeding, or ulceration. These masses may also cause localized disfigurement as cancer invades the underlying bone.

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Possible causes


Risk factors


The severity of oral masses depends on the type of mass. Some masses, such as those caused by oral papillomatosis, may not require treatment. Others, including cancer, can be potentially life-threatening. Dogs presenting with oral masses benefit from prompt veterinary attention. Emergency veterinary attention is required for oral masses accompanied by difficulty breathing, severe difficulty eating and weight loss, or excessive bleeding from the mouth.

Damage to the surface of oral masses may cause pain or bleeding. The appearance of the mass does not always provide an indication of severity, so thorough examination by a veterinarian is required to assess the severity of oral masses.

Testing and diagnosis


Diagnosis aims to identify the type of mass present. Diagnostics include:

  • A physical examination
  • Diagnostic imaging, such as X-ray or ultrasound
  • Fine needle aspiration
  • Biopsy
  • Bloodwork
  • Urinalysis

Some dogs may require sedation for thorough examination.

Treatments depend on the type of mass present, and may include:

  • Medication, such as antibiotics
  • Surgery to remove the mass
  • Chemotherapy
  • Radiation therapy
  • Palliative care

Similar symptoms


Oral masses are typically self-evident upon examination of the mouth.

Associated symptoms


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