Are your dog’s ears itchy, red, or smelly? These are signs of an ear infection, a common problem in dogs that is also occasionally seen in cats. Many pets experience an occasional ear infection, and these typically respond well to a short course of topical medications. But, some pets may experience chronic infections that don’t resolve with typical treatment, and keep coming back. These pets likely have multiple underlying causes or predisposing factors that must be addressed to stop the infection cycle.

Our Palm Valley Veterinary Center team can manage routine and chronic pet ear infections, but we may refer you to a veterinary dermatologist if your pet requires advanced diagnostics or treatments. 

How pet ear infections develop

Bacteria and fungi normally live on the skin and inside the ears in small, balanced populations, but in inflamed ears, bacteria and/or fungi can overgrow and cause infection. Infected ears become red, painful, and itchy, and may develop a thick, malodorous discharge, and the ears must be thoroughly cleaned with a medicated cleanser and treated with topical medications for one to two weeks. Ear infections are easy to identify, but the underlying inflammation cause that triggered the infection can be harder to pin down. 

When pet ear infections become chronic

Infections may fail to resolve, or resolve and quickly return, if the affected pet has underlying, predisposing, or perpetuating factors that may include:

  • Underlying causes — Allergic inflammation from food, the environment, or flea allergies is the top cause of ear infections. Others include autoimmune or inflammatory skin diseases, abnormal wax or oil secretion, tumors, polyps,  parasites, endocrine disease, and foreign bodies.
  • Predisposing factors — These factors, including excess moisture, immune suppression, pendulous ears or narrow ear canals, trauma from overcleaning, and viral upper respiratory illness, encourage microorganism growth.
  • Perpetuating factors — Perpetuating factors, which include middle ear infection, eardrum inflammation, and ear canal changes from chronic inflammation (i.e., thickening, hardening, proliferation), can complicate infections, and will not resolve if not addressed separately.

How pet ear infections are diagnosed

Your veterinarian can diagnose an ear infection and determine whether the cause is yeast, bacteria, or both, by microscopically examining  the ear discharge (i.e., cytology). Initial treatments are based on this test result. If treatment fails, your veterinarian will likely send an ear culture to a laboratory to identify specific bacterial strains, which will help them determine which medications will be most effective. 

Routine ear infections affect only the outer ear canal, but up to 88% of pets with chronic or recurrent infections have middle ear involvement, located behind the eardrum. This area of the ear cannot be seen in detail via an otoscope, preventing diagnosis of a middle ear infection, unless the eardrum is ruptured. Middle ear infection signs may include:

  • Pain when opening the mouth
  • Swelling around the ear base
  • Head tilt or dizziness

If conservative measures fail to heal a chronic or recurrent infection, a veterinary dermatologist can perform more advanced diagnostics to help to determine whether a middle ear infection or another underlying condition is the problem. Tests may include:

  • Video ear examination (i.e., video otoscopy)
  • Skin or ear biopsy
  • Skull X-rays or ultrasound
  • Head CT or MRI

Chronic pet ear infection treatments

Basic ear infection treatment involves ear cleaning and medication for one to two weeks, and follow-up cytology to ensure the infection is healed. Chronic infections require long-term or ongoing treatment, depending on the underlying cause. While many predisposing factors, such as ear canal shape, cannot be changed, treatments to eliminate underlying and perpetuating factors may include:

  • Allergy treatments (i.e., medications, immunotherapy)
  • Long-term topical and/or oral antibiotics or antifungals
  • Daily or every other day topical or oral steroids
  • Deep ear canal flushing with or without myringotomy (i.e., intentional eardrum rupture), while the pet is sedated
  • Immunosuppressant medications
  • Surgery to remove thickened tissue, masses, or the entire ear canal

If chronic ear infections are not addressed early, your pet’s ear canals may become thickened, scarred, and painful, and your pet may lose their hearing. A veterinary dermatologist can help to prevent these long-term complications and resolve your pet’s issue in as few visits as possible, but your commitment and dedication are also required. Sometimes, a pet’s ear disease progresses despite treatment, and surgery may be indicated in these cases to restore your pet’s comfort.

If your pet has developed itchy skin, smelly and painful ears, or other dermatological changes, contact us to schedule a visit and consultation with the Palm Valley Veterinary Center team.