Ear infections in cats and dogs are a common problem that can be frustrating to treat. These infections cause significant pain, and can lead to hearing loss if not addressed appropriately. Our Heritage Veterinary Clinic team wants to help by providing information about what causes ear infections in pets, and how these conditions are managed.

What causes dog ear infections?

Unlike a human’s ear canal, which travels linearly from the tympanic membrane to the outside, a dog’s ear canal has a horizontal component that allows debris, such as wax and skin oil, to accumulate. This provides food for the bacteria and yeast that normally reside in the ear, and allows the pathogens to multiply and cause infection. Other factors that can increase a dog’s ear infection risk include:

• Allergies — Dogs are frequently affected by environmental and food allergies, which disrupt the normal skin barrier, including inside the ear. Allergic dogs commonly suffer from chronic or recurrent ear infections.
• Endocrine disorders — Conditions such as hypothyroidism and Cushing’s disease cause hormone level changes that can put affected dogs at higher ear infection risk.
• Foreign bodies — Foreign bodies, such as grass awns, sand, and hair, can become lodged inside the ear and cause an ear infection.
• Moisture — Dogs who swim frequently are at higher ear infection risk, because the moist environment is ideal for pathogen overgrowth.
• Floppy ears — Dogs such as cocker spaniels and basset hounds, who have long, pendulous ears, are more susceptible to ear infections, because their ear conformation facilitates debris and moisture accumulation.
• Narrow ear canals — Dogs who have narrowed ear canals, such as Shar-peis, are at higher ear infection risk.
• Parasites — Parasites, such as ear mites, mange mites, and ticks can cause ear infections. 

What causes cat ear infections?

Ear infections aren’t as common in cats, and although they can be caused by allergies and foreign bodies, they tend to result from different problems that commonly include:

• Ear mites — Ear mites cause nearly half of ear infections diagnosed in cats.
• Ear polyps — Benign growths inside the cats’ ear canal can result in an ear infection.
• Viral infection — Viral infections, such as feline herpesvirus and calicivirus, can cause an ascending infection from the nasopharyngeal region that affects the ear.

How do I know if my pet has an ear infection?

Signs indicating your pet has an ear infection include:

• Black granules — Pets who have small, black granules inside their ear have an infection caused by ear mites.
• Pain — The excessive inflammation caused by ear infections typically results in significant pain, and you may notice your pet shaking their head, scratching at the affected ear, or vocalizing when the ear is touched. 
• Discharge — Infection inside the ear typically causes discharge from the pet’s ear.
• Odor — The bacteria or yeast multiplying in the pet’s ear can cause an offensive odor.
• Neurological signs — If the infection progresses to the middle ear, you may notice neurological signs such as head tilt, incoordination, and facial paralysis.

How are pet ear infections diagnosed?

You may think diagnosing a pet’s ear infection would be easy, but several pathogens can cause infection. In addition, underlying causes must be addressed to prevent recurrence. Potential diagnostics include:

• History — Our veterinary professionals take a thorough history to determine if your pet has had a previous ear infection and if they have any known health complications, such as allergic dermatitis.
• Physical examination — We perform a thorough physical exam to assess your pet’s overall health.
• Ear examination — We use an instrument called an otoscope to evaluate your pet’s ear canal and tympanic membrane. Your pet may require heavy sedation or anesthesia if they do not cooperate because of pain.
• Culture — We take a sample from your pet’s ear for a culture and sensitivity test to determine what pathogen is causing the problem and what antimicrobials will be effective.
• Imaging — In some cases, our veterinary team may recommend an X-ray or ultrasound to determine the damage to your pet’s ear.

Why should ear infections be treated?

Ear infections don’t resolve on their own, and they should be managed by a veterinary professional. If not treated appropriately, complications can occur, including:

• Aural hematomas — When pets shake their head excessively, they can cause an aural hematoma (i.e., blood accumulation between the skin and the ear flap cartilage). This condition is painful, and typically requires surgery to drain the blood and eliminate the space where the blood has accumulated. 
• Ear canal stenosis — If infection persists, scarring and tissue proliferation inside the ear can cause thickening and narrowing of the ear canal, which makes the infection especially difficult to resolve.
• Hearing loss — Severe cases can lead to hearing loss.

How are pet ear infections treated?

Your pet’s condition severity will determine how their ear infection is addressed. Potential treatments include:

• Parasite prevention medication — If your pet has ear mites, our veterinary team will prescribe appropriate medication that will eliminate the parasites.
• Topical treatments — Most simple ear infections can be remedied by ear cleaning and appropriate topical antimicrobial administration. 
• Systemic medications — In some cases, our veterinary team prescribes systemic antibiotics and pain medications to help address your pet’s ear infection.
• Surgical management — In severe ear canal stenosis cases, surgical intervention is necessary to remove the damaged tissue to help resolve the infection.

Ear infections in pets can be problematic, and they should be addressed as soon as possible to prevent complications. If your pet has a painful, stinky ear, contact the Heritage Veterinary Clinic, so our team can determine what is causing the problem and help alleviate their discomfort.