Parasitic Otitis in Dogs

The ear mites found most commonly in dogs are the parasites Otodectes cynotis. This eight-legged parasite lives on the wax and oils found in the ear canal of many animals. The scratching and head shaking that results from the itchiness and irritation they cause can damage the ear, leading to pain, secondary infections, ear hematomas, eardrum ruptures, and even permanent hearing loss. Dogs of any age can contract ear mites from other animals that have them.

Otitis is an infection that causes an inflammation of the outer ear canal, middle ear, or internal ear. Parasitic otitis, or otoacariasis, is an infection caused by ear mites. Characterized by crumbly discharge from the ears that can resemble coffee grounds, ear mites can cause discomfort and pain for your dog.

The symptoms seen in an ear mite infestation are caused by damage to the ear canal, middle and inner ear. Signs can include:

• Frequent scratching at ears
• Black debris in ear or discharge that resembles coffee grounds
• Head shaking
• Ear pain and discomfort
• Ear infections
• Rubbing ears or face on floor or objects
• Irritated, inflamed, and swollen ears 
• Crusts in or around ears
• Aural hematoma, or a blood blister between the layers of the ear
• Whining when ears are rubbed
• Hair loss from excessive grooming and scratching
• Depression
• Balance problems
• Head tilt
• Hearing loss

The cause of parasitic otitis in your dog is an infestation of ear mites, most commonly Otodectes cynotis. This mite lives on the skin surface and ear canals of dogs and other small mammals, and lives its entire life cycle on its host. Otodectes cynotis is barely visible, and can be seen against a dark background as a white speck. Ear mites are transmitted from infected animals to healthy ones through direct contact and are highly contagious.

If your dog has been scratching at his ears excessively, you may need to take him to the veterinarian as he most likely has an infection. Ear mites and other infections can cause irreparable damage if left untreated. 

Begin by telling your vet when you first noticed symptoms, as well as any changes you’ve noticed in your dog. Your vet will first assess your dog’s level of discomfort. Sedation may be required for the exam if there is a substantial amount of pain. The ear is then examined with an otoscope to assess the state of the ear canal and eardrum. Often, your veterinarian will be able to instantly see the ear mite infestation, as well as the resultant swelling and infection. A sample of the ear discharge is taken and microscopically examined, which can confirm the presence of ear mites. If ear mites are diagnosed, your vet may examine your dog more thoroughly, as mites can live on other parts of the body.

Once ear mites have been diagnosed in your dog, treatment aims to eliminate the mites from your dog and any other animals in the household. Since ear mites are so contagious, often if you find ear mites on one pet, the others in the home probably have them too. Have your other animals checked and treated at the same time to ensure the mites are eradicated. 

The first step is to have the ears cleaned by your vet using topical antiseptics that are specifically formulated for dogs. You will also be instructed to routinely clean your dog’s ears at home using the solution recommended by your veterinarian. Parasitic medications are then prescribed for several weeks, after which time your dog may be examined again to assess the effectiveness of the treatment. Other medications may be prescribed to deal with the discomfort and secondary infections that may be present, such as antibiotics, pain relievers, or anti-inflammatories to reduce ear swelling.

While there are no specific products available to rid mites from other areas of your dog’s body, your vet may recommend a shampoo or dip formulated with an appropriate parasitic. Many products that are used for flea control can also kill ear mites. Multiple treatments may be necessary to kill all the ear mites. Be sure to clean all bedding, toys, and areas your dog frequents to prevent reinfection.

Recovery is good if the ear mites are treated before they do permanent damage to the ear. Treatments usually eliminate the mites and can clear up any resultant infections. Your veterinarian will show you the proper way to clean your dog’s ears, as you will need to do this often at home during recovery. You will also need to administer medications, drops, or creams, or give your dog a medicated bath. Improvement can often be seen within a few weeks, after which time, you may need to get your dog re-tested to assess if the ear mites have been eliminated.

To prevent a future ear mite infection, use a parasite control that kills ear mites, and regularly check your dog’s ears to catch any infections when they begin.