What is Otitis?
Otitis is the medical term for inflammation of the ear. Unlike humans, dogs and cats have a vertical and horizontal ear canal forming an L shape. This makes them more prone to fluid accumulation and debris. Inflammation can be caused by yeast, bacteria, parasites and allergies. Ear infections may be composed of more than one causative agent or secondary to an underlying condition.
There are three regions of the ear: the outer (externa), middle (media) and inner ear (interna). The outer ear is made up of the pinna (the part of the ear you see made of cartilage) and the vertical and horizontal ear canal. The middle ear includes the eardrum, the eustachian tube (connects middle ear with nose), the bulla (circular air-filled space space) and three small bones known as the malleus, incus and stapes. The inner ear contains the cochlea (hearing structure) and the vestibular system (balance structure).
Dogs and cats that have a weakened immune system or a skin disease caused by allergies are more susceptible to infection. Dogs with large floppy ears, such as Beagles and Basset Hounds are predisposed to ear infections because of reduced ventilation. Also, increased moisture in the ear that can result from swimming or bathing can increase risk of infection. Chronic ear inflammation and infection can cause the skin to thicken which narrows the ear canal further reducing ventilation.
Otitis interna (inflammation of the inner ear) usually develops from an external ear infection or a foreign object that damages the eardrum. Otitis interna can temporarily or permanently affect hearing and balance. Middle ear and inner ear inflammation may also affect sympathetic innervation of the face resulting in nystagmus (involuntary repetitive eye movements), facial nerve paralysis, pupil constriction, eyelid drooping and protrusion of the third eyelid on the same side of the ear infection. Clinical symptoms of otitis media/interna may also be caused by a tumor or polyp (a benign growth).
Clinical Symptoms Include...
Clinical symptoms will vary depending on the pathology, but here is a list of most potential presenting symptoms of ear infections.
Otitis externa (outer ear):
- redness
- swelling
- itching (rubbing, scratching)
- blistering
- alopecia (hair loss from scratching)
- head shaking
- discharge and pus
- foul odor
Otitis media (middle ear)
- redness
- swelling
- itching (rubbing, scratching)
- blistering
- alopecia (hair loss from scratching)
- head shaking
- discharge
- pus
- facial nerve paralysis
- pupil constriction
- eyelid drooping
- protrusion of the third eyelid
- sinking of eyeball into socket
Otitis interna (inner ear)
- redness
- swelling
- itching (rubbing, scratching)
- blistering
- alopecia (hair loss from scratching)
- head shaking
- discharge and pus
- facial nerve paralysis
- pupil constriction
- eyelid drooping
- protrusion of the third eyelid
- sinking of eyeball into socket
- nystagmus (involuntary repetitive eye movements)
- inability to balance
- poor coordination
- head tilt to the affected side
- anxiety and distress
- loss of hearing
Diagnosis will vary depending on presenting clinical symptoms and which location of the ear is thought to be affected. For all presenting ear complaints, a thorough ear examination will be performed with an otoscope, which will allow the veterinarian to see the middle and inner ear unless vision is being blocked by a mass or discharge. A sample may be obtained via a swab and evaluated under a microscope for the presence of yeast and bacteria. In addition, a culture may be recommended to gain further diagnostic information. For patients with suspected allergy related symptoms, allergy testing may be recommended. Unfortunately, otitis interna is difficult to diagnose especially if the eardrum is intact. This may require a radiograph, CT scan or MRI imaging. If Otitis is thought to be related to underlying immune-suppressing condition, blood work and other diagnostic testing may be performed.
Treatment
Treatment will largely depend on the causative agent. If an underlying disease is suspected, a further workup will be required in order to treat or control the underlying condition. Immediate treatment of a current infection may consist of medicated ear drops and/or systemic medications that fight off yeast, bacteria, and/or parasites. Topical or oral steroids may be prescribed in conjunction to decrease inflammation. If allergies are suspected, treatment will typically involve antihistamines, immunosuppressants and anti-itch medications as well as change in diet if allergies are thought to be food related. If a tumor or polyp is present, surgery may be the recommended treatment. In addition, surgical treatment may be required for chronic ear infections unresponsive to other less invasive medical treatments. Your veterinarian may recommend your pet wear an e-collar (cone) to prevent scratching and rubbing until the infection has healed. It is important to follow your veterinarians recommendations as scratching can worsen the problem and delay healing. Also, be diligent about applying medicated ear drops as prescribed as missing doses delays healing.
Prevention
It’s important to routinely check inside your pet’s ears for signs of inflammation. Look for excessive wax, debris, pus, redness, cuts and scabs. You can also smell the ear. A foul odor can be sign of infection. If you notice any abnormalities or clinical symptoms of infection or inflammation, such as frequent head shaking or scratching make an appointment with your veterinarian. If your pet tends to get a lot of debris or wax, cleaning and flushing the ears with an over-the-counter cleansing solution and cleaning the the pinna with cleansing wipes may be beneficial. It is important not to overdo it as some cleansers can dry out the skin. For dogs without ear issues, once a month ear cleaning should be adequate. For breeds, such as Cocker Spaniels that have a lot of hair in their ears, regular grooming and trimming of hair in and around the ears is recommended. It’s also a good idea to dry ears after bathing and swimming to prevent build-up of moisture.
I recommend speaking with your veterinarian about what ear cleanser is best suited to your pet’s specific needs. I personally use Epi-Otic Advanced Ear Cleanser as I have found it to be the best ear cleanser for my dogs. It can be used on dogs and cats of any age. It is non-irritating and has anti-adhesive properties that help prevent the build up of bacteria and yeast. It does not require a prescription. Flushing ears is not recommended if the ear drum is ruptured as it can cause irritation and worsen symptoms.
How To Clean Ears
Make sure the nozzle is clean before each use. Hold ear flap up vertically and insert the nozzle into the opening of the ear canal and gently squeeze until the ear canal is full of fluid. If the nozzle touches the ear, wipe it down with rubbing alcohol before the next use to prevent spread of infection.
Massage the base of the ear for about 30 seconds to break up debris (you should hear a "squishing" sound). Wipe the inside of the ear flap with a cotton ball or gauze. Always cleanse the ears before applying medicated ear drops.