Ear Margin Hyperkeratosis in Dogs

If you notice your dog has crusty lesions on the edges of his ears, or on any part of his ear, he may have what is known as ear margin hyperkeratosis.  This condition is characterized by thickening of the skin on his ears, excessive head shaking, and scaly or greasy plugs on the ear margins.  Your veterinarian will be able to diagnose his condition by ruling out other possible conditions and by taking skin samples and examining them with the microscope.  If your dog is diagnosed with ear margin hyperkeratosis, there is no cure but there are ways to manage it and keep your dog happy and comfortable.

Ear margin hyperkeratosis affects the outer edges of your dog’s ears.  If you notice crusting or greasiness on the outer edges, it would be a good idea to take him to his veterinarian for an evaluation.

Signs of this condition may include:

• Thickening of the skin on the ears
• Mild lesions on the pinna
• Scaly or greasy plugs on the pinna margin, not itchy 
• More severe cases affect the entire ear pinna, not just the edges
• Head shaking

Types

Ear margin hyperkeratosis can also be known as ear margin seborrhea or orthokeratotic hyperkeratosis.  It is characterized by abnormal thickening of the outer layer of skin.  This condition is commonly found to affect dogs with pendulous ears such as Dachshunds and Cocker Spaniels.  As the condition progresses, the scaling often moves from the edge of the ear to the entire ear.

This condition can be a side effect of hypothyroidism in some dogs.  In other cases, it may be caused by a hair follicle problem.  Most commonly, hyperkeratosis of the ears is regarded as a primary keratinization defect.  This means there is no cause to the condition; it is the condition. If it is a primary disease, there is no underlying illness you have to worry about treating; you just have to treat the ears.

When you arrive at the veterinarian’s office, she will start her diagnostic process by collecting a verbal history from you.  For example, she will want to know what signs you have seen on your dog and when you first noticed the development of his signs.  She will also want to know how fast each sign has been progressing and if it seems to impair his daily routine.  She will then proceed with performing a full physical exam.  While it may be obvious the lesions are on his ears, she will want to check him over entirely for other symptoms that could be indicative of an underlying cause of his condition.  

In cases of suspected ear margin hyperkeratosis, your veterinarian may need to rule out other possible medical conditions first.  For example, fly bite dermatitis in dogs causes very similar symptoms as to those of ear margin hyperkeratosis.  Additional diagnoses she may need to rule out include scabies and solar dermatitis, to just name a few.  In order to rule out these conditions, she may want to perform diagnostic testing.  It would involve taking a skin scraping sample from the affected area of your dog.  She will gently scrape a small sample from the superficial layer of your dog’s ear tips to examine under the microscope.  This will allow her to evaluate the appearance of the skin cells as well as rule out external skin parasites.

Ear margin hyperkeratosis can be complicated by a yeast infection or bacterial infection.  She will want to ensure your dog does not currently have an ear infection in his canal as well as on the surface of his ear pinna.  This may involve taking a cytology sample from his ears or ear canals.   

Other testing may be requested by the veterinarian depending on your dog’s signs.  If she suspects his condition is a secondary development to a different illness, she may want to perform diagnostic testing to determine the cause. Depending on what she suspects, the testing can vary.

Many dogs with this condition respond well to medicated shampoos . Examples would be sulphur, salicylic acid, selenium sulphide, or benzoyl peroxide shampoos.  Your veterinarian will be able to prescribe you this as it is not something that can be found over the counter.  If you do find something over the counter, it may be similar, but the prescription shampoo typically works better.  

Close clipping of the hair on the affected area is also helpful, as it can help prevent matting of the hair.  It will not necessarily prevent the condition from developing but it may slow or stop its progression.

Other treatments will be administered depending on your dog’s needs.  She may send you home with an ointment or spray to apply to the ears.  If there is a yeast or bacterial overgrowth, it is possible oral medications will also be sent home for you to administer over a course of time. If your veterinarian discovers there is an underlying cause to your dog’s signs, she will administer therapies appropriately.

There is no cure for this condition but you can reduce how much it affects your dog.  With treatments suggested by your veterinarian, you should be able to keep your dog comfortable.  The medications should also help prevent or slow the progression of the hyperkeratinization before it expands further over his ear pinna.  With the proper treatments applied, your dog’s prognosis of recovery or at least prevention of progression is good to fair.