Dog Ear Tumors: Identifying and Understanding Ear Growths

Tumor is a scary word, so thankfully, dog ear tumors aren't that common. A tumor is a mass that can be benign or malignant (cancerous). If you notice a growth of any sort on your dog's ear or if they are having ear-related issues, such as scratching, head shaking, or ear discharge, it's important to take them to a veterinarian right away.

An ear tumor is a growth, benign or malignant, that develops out of any of the tissues associated with the ear canal. Benign tumors tend to stay in the same location and don't spread to other body parts. Malignant tumors can spread to other body parts and organs, like the lungs, liver, and lymphatic system.

Ceruminous gland adenocarcinoma is the most common malignant ear tumor, followed by squamous cell carcinoma. Ceruminous gland adenomas are the most common benign ear canal tumors. Other benign growths include basal cell tumors, inflammatory polyps, and papillomas.

The cause of ear canal tumors isn't known, but chronic inflammation of the ear canal, such as that due to ear infections, is suspected to give rise to unusual growth and tissue development, ultimately resulting in a tumor.

Dogs with drooping or floppy ears may be predisposed to ear tumors because their ear canals may stay moist, providing a breeding ground for yeast and bacterial infections. Infections can give way to inflammation, sometimes resulting in benign or malignant tumors.

Ear tumors can form out of the following tissues:

• The skin glands that make earwax and oil
• Middle and outer layers of skin
• Bones
• Muscles
• Connective tissues

The cocker spaniel is the breed mostly likely to develop an ear tumor. Middle-age and older dogs are also at increased risk, with the likelihood of cancer being higher in dogs over 11 years of age.

Your dog's ear has four parts vulnerable to tumors:

• The pinna (the ear flap)
• External ear canal
• Middle ear canal
• Inner ear canal

Tumors are more common in the external (or outer) ear canal and pinna than in the middle and inner ear. Ones in the outer ear canal can be seen during an otoscopic examination by your veterinarian.

There are some behavioral and visual clues that may indicate your dog has a tumor in their ear. Also note that many of these things can be due to other reasons as well. In addition to seeing a growth, clinical signs for which to watch are:

• Swelling
• Ear odor
• Discharge, including pus and crust
• Chronic ear infection
• Ear swelling and/or ear redness
• Facial swelling
• Swollen lymph nodes
• Bleeding and ulceration, which is more likely to occur with malignant tumors, but benign tumors may bleed as well
• Head shaking and/or more ear scratching than usual
• Diminished hearing or deafness
• Neurologic signs, like facial nerve paralysis
• Depending on the location of the tumor, your dog may show inner ear/vestibular signs, such as a head tilt, incoordination, loss of balance, and rapid eye movements (nystagmus) that are either back and forth or up and down

Ear tumors can take on a variety of forms. Some are flat lesions, some are lumps perched on stalks, and others are masses filling the ear canal. Common colors include white, pale pink, purple, and black, sometimes containing a dark and oily fluid.

When you find a tumor in your dog's ear, have your veterinarian take a look. Since ear tumors can sometimes not have obvious signs, your veterinarian might also find one while looking in your dog's ear during a routine physical examination. A dog who is too painful for an ear exam due to inflammation may require sedation.

Tests to help diagnose your dog's condition include:

• ‌Fine needle aspirate or biopsy:‌ If the growth is in a place accessible enough, the veterinarian will take a sample of it to determine definitively whether a lump is malignant or benign. They may also sample the lymph node closest to the ear.
• ‌Radiographs (X-rays):‌ If an ear tumor is cancerous, your veterinarian may take X-rays of your dog's lungs to see if there is metastasis.
• ‌CT scan or MRI:‌ If your dog's ear tumor is cancerous, they may need to have a CT scan of their head and neck to determine the extent of the tumor prior to surgery and other treatments.

Surgical excision is the treatment of choice for all tumors, sometimes including laser surgery. If the tumor is cancerous, a dog may need a more extensive surgical procedure called a total ear canal ablation (TECA) and bulla osteotomy. This means that the inner, middle, and outer ear canal are all removed, leaving just the ear flap with no ear canal opening.

If a tumor can't be completely removed, other treatments may be necessary, such as radiation therapy, chemotherapy, and supportive care to treat infections and pain.

Tumors of the ear canal in dogs aren't that common, so if you notice a growth on your dog's ear, schedule a physical examination for them right away. But ear growths in dogs may occur in a place where pet parents can't see them, such as in the middle ear. They don't always produce obvious symptoms, so watch for other symptoms, such as head shaking, scratching at an ear, ear odor, or ear discharge. Some ear tumors in dogs are benign, and they don't spread, whereas others are malignant, and they can potentially spread to other parts of the body.