Pets are commonly affected by ear infections, and simple cases are treated easily with appropriate antimicrobials. However, if an underlying cause is contributing to your pet’s ear infection, the condition can become chronic and difficult to treat. Our American Animal Hospital Association (AAHA)-accredited team at Boca Midtowne Animal Hospital can diagnose your pet’s painful ear, and determine whether an underlying cause is to blame. To help you better understand your pet’s condition, we are also sharing facts about chronic ear infections in pets.
Classifying pet ear infections
Ear infections are classified based on the part of the ear that is affected. Conditions include:
- Otitis externa — The external ear canal runs between the outer ear and the ear drum. When this area is infected, the condition is called otitis externa.
- Otitis media — The middle ear is separated from the external ear by the eardrum and connects to the back of the nose and throat by a narrow passageway called the eustachian tube. When this area is infected, the condition is called otitis media.
- Otitis interna — The inner ear is the deepest part of the ear. This small compartment contains the cochlea, which is responsible for hearing, and the semicircular canals, which are responsible for balance. When this area is infected, the condition is called otitis interna.
Causes of dog ear infections
A dog’s ear canal is more vertical than a human’s, forming an L-shape that can hold fluid easily. This predisposes dogs to ear infections. The dog’s ear normally contains microorganisms, but when conditions allow these bacteria and yeast to overgrow, infection occurs. The most common culprits are Staphylococcus pseudintermedius and Malassezia pachydermatis. Conditions that can lead to microorganism overgrowth include:
- Allergies — Hypersensitivity disorders, especially environmental and food allergies, can cause the skin barrier to break down and wax production to increase in the ear, leading to ear infections. Allergies are the most common underlying cause of recurring ear infections in dogs.
- Hypothyroidism — The thyroid gland regulates the body’s metabolism, and in hypothyroid dogs, the gland doesn’t produce enough thyroid hormone, affecting numerous body systems and leading to a predisposition for recurring skin and ear infections. Other signs include unexplained weight gain, lethargy, hair loss, and increased dark skin pigmentation.
- Hyperadrenocorticism — This condition occurs when your dog’s adrenal glands overproduce the stress hormone cortisol, reducing the body’s ability to fight infection. Other signs include increased appetite, increased thirst and urination, hair loss, and an enlarged abdomen.
- Foreign bodies — Grass awns, hair, sand, and other foreign bodies can become trapped inside a dog’s ear, leading to an ear infection.
- Excessive moisture — Dogs who enjoy swimming are prone to ear infections because water can become trapped inside their ear, allowing bacteria and yeast to accumulate.
Ear infections can be extremely painful, and signs include head shaking, scratching at the affected ear, malodorous discharge, and vocalization when the affected ear is touched. Dogs may develop neurological signs if their middle or inner ear is affected.
Causes of ear infections in cats
The most common microorganisms cultured in cat ear infections are Staphylococcus, Otodectes, and Malassezia. Conditions that can cause ear infections in cats include:
- Ear mites — Ear mites commonly parasitize cats, especially kittens, and ear mite infections can allow bacterial and yeast overgrowth.
- Allergies — Environmental and food allergies are a common predisposing cause of ear infections in cats.
- Upper respiratory infections — Middle ear infections in cats usually are caused by an infection from their nasopharyngeal region. Common culprits include feline herpesvirus and calicivirus.
- Ear polyps — Polyps are inflammatory growths most commonly noted in cats less than 2 years old.
Cats tend to hide health conditions, and they may suffer in silence. Signs include excessive ear scratching, lowered ears, odor from the ear, and head shyness. Affected cats also may hide more and have a decreased appetite. Cats affected by otitis media or otitis interna may exhibit neurological signs, too.
Treating pet ear infections
A sample from your pet’s ear is cultured to determine the microorganism causing the problem. Ear infection treatment includes:
- Cleaning your pet’s ear — We will clean your pet’s ear thoroughly to remove excess wax and debris. Sedation or anesthesia may be needed for this procedure since their ear may be extremely painful.
- Topical antimicrobials — An appropriate antimicrobial will be prescribed based on your pet’s culture results. These medications typically must be applied for one to two weeks.
- Systemic medications — Oral antimicrobials and pain medications also may be needed to address the infection.
- Diagnosing underlying cause — In recurring cases, your pet may need blood work, allergy testing, or a food trial to determine the underlying cause.
- Surgical management — In severe cases, surgery may be necessary to resolve the problem. Procedures include:
- Vertical ear canal ablation — This procedure involves removing the vertical portion of the ear canal.
- Total ear canal ablation and bulla osteotomy (TECABO) — The entire ear canal must be removed in cases where the ear canal is completely calcified from thickened tissue.
Preventing ear infections in pets
Not all ear infections can be prevented, but you can take steps to decrease your pet’s risk. These include:
- Providing parasite prevention — Flea and tick prevention medication protects your pet from ear mites, and they should receive year-round protection.
- Drying your pet’s ears — Dry your pet’s ears thoroughly after bathing or swimming.
- Cleaning your pet’s ears — If your pet is prone to ear wax accumulation, clean their ears regularly using an appropriate cleaning solution.
Ear infections can be distressing for pets, and discovering the underlying cause is important to prevent recurrence. If your pet has a painful or smelly ear, contact our Fear Free team at Boca Midtowne Animal Hospital so we can determine what is causing the problem.