Diseases of the Pinnae in Dogs

The outer ear on dogs can be quite vulnerable to injury, infection, and swelling, with a number of differing triggers. It is important to examine both the inside and the outside of your dog's ear and to assess the skin condition on a regular basis.

Although many of these may heal on their own or do not require veterinary care, veterinary attention can help to prevent permanent scarring, secondary infections, and advanced parasitic infestations, as well as to revealing any underlying causes.

Many of the disorders that frequently affect the pinnae, more commonly known as the outer ear, can be distressing and disfiguring to your pet without proper treatment.

Many of the symptoms of these pinna disorders are similar. Any of these disorders could produce symptoms of:  

• Head shaking
• Pinnae is hot to the touch
• Redness of the ear
• Scratching at the ear
• Sensitivity to touch
• Swelling of the pinna

Although changes in the appearance and texture of the outer ear are seen with each of these disorders, the changes that occur may be more divergent.

Types

A sampling of some of the disorders that can affect your canine’s outer ear may include:

Canine Juvenile Cellulitis

This disorder appears to be immune mediated, typically affects dogs between the ages of three weeks to eight months and causes lesions to appear anywhere on the body, although the most common placements for these lesions are on the face and the outer ears of the dog. 

Frostbite

This disorder occurs in the pinnae when extreme cold causes the outer ear to experience tissue injury or death. 

Myiasis

Flies have been known to lay their eggs in open wounds on the outer ear caused by damage to the pinna from itching, bites from insects, or injury. Myiasis occurs when the eggs hatch and maggots infest the skin.

Seborrheic Dermatitis

The dandruff-like appearance of this disorder is caused by an overabundance of sebum being produced by the skin and is particularly noticeable on the outer ears.

• Diseases and disorders - The outer ear can be affected by either congenital disorders like congenital hair loss or acquired disorders like ear hematomas or bacterial infection
• Environmental irritations and allergies - Disorders caused by weather conditions, such as frostbite or sunburn can sometimes cause serious and irreversible damage to the pinnae and allergies to pollen or dust can cause skin irritation that can cause itching and swelling of the outer ear 
• Pest problems - The reaction to pests like fleas, ticks, and mites may be particularly distressing when they attack the outer ears; along with transmitting diseases, these parasites can cause dermatitis to develop in dogs that are sensitive to them triggering itchy and inflamed skin on the outer ears

When your dog is brought into the veterinary clinic, any open wounds or lesions found on the ear will be thoroughly cleaned and evaluated for infestation, infection, or necrosis and a sample of the skin may be taken to perform a procedure known as cutaneous cytology. This procedure examines the sample microscopically and is particularly helpful in spotting parasites as well as some types of bacteria. Standard diagnostic tests such as a complete blood count, biochemical profile, and a urinalysis, are also likely to be completed at this time.These tests can help rule out certain underlying disorders and may give a clue as to the cause of the discomfort. 

If an allergic reaction is suspected, then allergy testing will also occur. If the allergy is an environmental or contact allergy, it will typically be diagnosed using either blood test or intradermal testing, whereas food allergies are diagnosed by using an elimination diet. The veterinarian is also likely to examine the ear canal as well as the pinnae to check for infections, wax buildup, or foreign bodies that may be aggravating the situation.

The condition of the ears and the final diagnosis will dictate the treatment path for your particular canine. Some of the conditions of the pinnae can cause severe damage or death to the tissues of the ear, so any dead tissues will need to be removed, and the living tissues underneath it will require cleaning. If pests such as fleas or mites are found on your pet’s ears an appropriate pesticide, usually a topical product, will be prescribed to kill the invaders. Dogs that are experiencing allergic reactions will either eliminate the allergen from their environment as much as possible or will be administered antihistamines in order to reduce the reaction.

Corticosteroids may also be employed to reduce any itching or swelling of the ear, and if a bacterial or fungal infection is detected then either antibiotics or fungicide will be applied to eliminate the disease. While antihistamines that were initially intended for human use, such as Benadryl, are often recommended for treating canines as well, it is important to consult your veterinarian regarding the dosage as it can vary from dog to dog. With allergies that are consistent or are resistant to antihistamines, immunotherapy may be recommended as a way to desensitize the animal.

These disorders often are accompanied by open wounds, sometimes for quite a while after successful treatment. It is critical to ensure that these wounds remain clean and free of debris while they are healing. Your dog should be prevented from licking, chewing, or scratching at their ears during the recovery period both to protect the ears and to protect the animal from ingesting something inappropriate. In some cases, use of a Victorian collar may be required to remove temptation. Administer all topical and oral medications as prescribed, even if the skin appears healed or the wounds do not appear to be infected. Discontinuing antibiotics or pesticides early may result in a reoccurrence of any infections or infestations.