Pinna is the outer ear of the dog. It may develop a number of skin abnormalities, but most of them are associated with other skin conditions found somewhere else in the body. Diseases originating in the external ear are rarely seen in dogs. Outer ear disorders are diagnosed by a thorough physical examination, in addition to reviewing the medical history of the dog, as well as the results of other tests.
Parasitic infestations are the most common cause of the disorders of the pinnae as they cause inflammation of the skin, often accompanied by severe itching, swelling and redness. Even blisters may appear. These symptoms develop either due to the insects’ bites or because of the dogs’ hypersensitivity towards the infestation. Skin mites are often concentrated on the edges of the pinnae, and they may burrow into the skin, causing severe irritation. Their presence is not easy to detect, and the veterinarian may have to reach a diagnosis after taking skin scrapings repeatedly and testing them for evidences of infestation.
Canine Juvenile Cellulitis
The inflammation resulting from an infection of the tissues underlying the skin is referred to as cellulitis. As the name indicates, canine juvenile cellulitis is a disorder affecting young dogs. This disease condition that results in a large collection of small, pus-filled bumps or raised areas on the skin of the ears and the face is not very common, but it may occur occasionally in puppies in the age group of 3 weeks to 4 months. Young ones of Dachshunds, Golden Retrievers and Gordon Setters are more prone to this disorder, but it rarely occurs in older dogs.
In addition to the inflammation on the face, and the thickening of the pinnae, the lining of the ear canal also may become inflamed, and a raised area filled with pus may develop there. Inflammation of the lymph nodes can be seen on the lower jaw as they become excessively swollen.
Observing the puppies carefully for changes in their coats, and the face, may help you detect the development of bumps under the skin. The dog should be taken to the veterinarian for a thorough check-up as soon as you see any inflammation or raised area or lumps in the ears or the face. Canine juvenile cellulitis should be treated early; otherwise it may result in scarring.
Hematomas are swellings filled with fluid. Ear hematomas may occur on the inner surface of the pinna in dogs. It is not clear why these swellings develop, but allergic reactions to some foods or environmental factors may be possible reasons. Inherited predisposition to this disorder is seen in some breeds, where an allergic response to an environmental agent, or a food item, primarily starts in the ear canals, resulting in the inflammation of the pinnae, often accompanied by itching. The dog may indicate the itching and discomfort by scratching the affected ear and shaking its head.
Surgical drainage and flushing of the swollen part is the main treatment. After draining the fluid completely, a soft drain pipe may be left in place to avoid fluid build-up in the future.
This condition results from flies biting the dog’s ears, causing irritation. Not only dogs, but horses too, are affected by this stable fly menace all around the world. Wherever the fly bites, small, raised bumps appear. They are hard, red, and round, with a bloody crust in the center of the bump. Severe itching may be present. Tissue changes may develop, especially on the tip of the pinnae. In dogs having floppy ears, it may occur on the surface of the ears at the point where they fold down.
Fly strike can be avoided by using fly repellents on the dog and in the environment to keep away these insects. The number of flies in the environment can be reduced by prompt removal of manure from the stables and spraying insecticides in the area.
This is an ear disorder limited to colder climates, and generally affects dogs that are not well adapted to the colder geographical regions. Frostbite affects the poorly insulated extremities of the body; and the ears, especially the tip and the edges, are severely affected. Paleness of the skin accompanied by pain and swelling may be the first sign, but the skin may become inflamed to a red color too. Rain and wind exacerbates the effects of cold and increase the severity of the frostbite, resulting in tissue death at the tip of the ear. The dead tip may be shed later on.
If the dog’s ears are affected by frostbite, they should be rapidly warmed with gentle heat. Surgical removal of the dead tissue may spare the dog unnecessary pain and discomfort, and promote healing, but surgery is usually done only after determining the extent of the damage caused.
Loss of hair along the edges of the outer ear is a common occurrence in dogs. It may start spontaneously without any apparent reason, and usually have a progressive run of many months, and then stop just as suddenly. Miniature Poodles have periodic hair loss on the surface of the outer ear where it curves outwards. The hair usually regrows without any other incident, so there is no need to treat this disorder.
Hair loss on the outer ear
This is an outer ear disorder with a hereditary factor. Some breeds of dogs such as the Italian Greyhounds, Chihuahuas, Whippets and the Dachshunds are especially prone to hair loss on their outer ears. The disorder typically starts when the dog is about a year old or more, and the first sign is a thinning of hair coat of the outer ears. By the time the dog is 8-9 years old, the outer year may have lost all the hair. Not only the ears, but the lower parts of the chest and the neck may also lose hair. The hair loss may extend to the thighs and the back too. Other than the loss of hair, no other symptoms are present. There is no treatment to eliminate the disorder, but some drugs have been found to be helpful to some extent.
The outer ear as well as the ear canal may be affected by immune disorders that may affect other parts of the body such as the mucous membranes, skin, nail beds and nails, footpads and tail. Lesions may develop in these areas. A biopsy of these lesions may help diagnose the autoimmune disease.
This infectious disease called sarcoptic mange is the result of a mite infestation. These parasites burrow into the skin, causing small bumps accompanied by severe itching. The bumps are initially round and red in color, but may later become open sores not only on the edges of the ears but in other areas of the body also. Constant scratching by the dog may be the cause of these sores, as well as of the scaling of the skin and the crustiness that follows. The mites get transmitted from one dog to the next through direct contact. Sarcoptic mange is a worldwide problem in dogs.
The external symptoms and the dog’s exposure to other dogs with the same disease can help the veterinarian diagnose the condition. The evidence of the mites’ presence may be obtained by examining skin scrapings, but usually several scrapings may be needed. Mange is treated with antiparasitic injections and dips to eliminate the mites, but reinfestation may occur when the treatment is over, as these parasites can survive away from their hosts for extended periods of time. Cleaning all the bedding, grooming kits and other things in the dog’s environment thoroughly and repeatedly may help prevent a recurrence.
Seborrhea and Dermatosis
Seborrhea is characterized by excessively oily skin along the edge of the outer ear. Dermatosis is another condition affecting the skin of the ear edges. Even though these ear disorders can occur in breeds with floppy ears, Dachshunds are the most affected. They are more frequently found on the ear tips, but can occur all along the edges too. The cause of these conditions is not known but they have typical symptoms such as scaly deposits on the basal portion of the hair shafts. The scales are yellow or grey in color and have a waxy texture. The hair may fall out in clumps or can be pulled off easily, and the skin underneath may look shiny. Severe cases may result in the cracking and swelling of the edges of the outer ear. The veterinarian may examine the ears of the dog and prescribe appropriate medication to resolve these disorders.
Ticks are usually attached to the pinna of the dog, but they can invade the ear canal too, causing irritation at the spot where they are attached. The ear tick in particular inhabits the external ear canal of not only dogs but other animals too. It is the immature ones of these soft-shelled parasites that may cause severe irritation and inflammation in the ear canal. They have a wide distribution, occurring in Africa, India, South and Central America as well as in the southwestern United States.
The dog may show symptoms such as head rubbing and head shaking due to the irritation caused by the ticks in the ear canal. The outer ears may droop, and ear canal disorders may develop. The veterinarian may examine the ear and take a smear to test for the presence of eggs, larvae, or the adult forms of the ticks inside the ear, and prescribe anti-parasitic medication. But not only your dog, but the local area also should be treated to eliminate these parasites. Otherwise, the infestation may recur.