Among the various skin disorders affecting man's best friend, scabs on the edges of dog ears may be an annoying ordeal to deal with. Not only are the scabs very unsightly, but they may be difficult to treat especially when an exact underlying cause has not been found. The causes for scabs on the edges of a dog's ears are various, and the best way to determine exactly what's causing them is through a trip to the vet. Following is some information about scabs on the tips of a dog's ears, potential causes and treatment options.
About Scabs on Dog Ears
A dog's ear tips are the thinnest part of the ear and are therefore particularly vulnerable. When scabs are formed on the edges of a dog's ears, the skin condition is referred to as ear edge dermatitis. This medical term though is not a diagnosis, the word dermatitis indeed is just a general term that's meant to depict an inflammation of the skin.
Ear edge dermatitis in dogs generally consist of hair loss, crusting and presence of scabs and ulcers. Depending on the underlying cause, there may or may not be itchiness. From a diagnostic standpoint, it may help the vet to determine whether the dog has possibly caused the scabs from scratching at the ears in the first place.
Also, it's a good idea to let the vet know whether the dog has been kept outdoors in cold whether or whether there are flies often hovering around the dog' ears. There are several potential causes of scabs on dog ears, and providing as much information as possible can help the vet. Following are several potential causes for ear scabs on the edges and tips of a dog's ears.
A Case of Scabies
Scabs on the edge of ears have been considered for quite some time the signature sign of canine scabies (sarcoptic mange), along with scabs on the dog's hocks, elbows and abdomen. This is because mites prefer to live in areas with little hair.
Dogs with scabies often have a history of being around other dogs such as when being boarded or at day care or when being groomed. In dogs living in the country, exposure to foxes, wolves, coyotes or stray dogs can be a contributing factor. Dogs with a lowered immune system such as dogs taking steroids or dogs suffering from low thyroid levels may be also predisposed.
Dog with scabies are typically itchy, and will develop hairless, crusty areas on their skin. These symptoms can mimic a skin allergy and it often can be misdiagnosed. However, a deep skin scraping taken from the ear edges, hocks, elbows or abdomen, may show proof of this pesky parasite.
A further diagnostic clue is derived from dogs who respond by scratching when their ear tips are touched (pinnal-pedal scratch reflex).
Diagnosis is not always easy though, and sometimes the only proof is response to treatment which consists of several dips and several other medications to reduce itching and treat any secondary infections.
A Hormonal Problem
Sometimes, hormones may be at the root of the problem when it comes to scabs on the edge of a dog's ears. One possibility is hypothyroidism, low thyroids levels in dogs which causes a variety of skin problems.
Dogs with low thyroid levels though typically tend to show other symptoms such as increased weight, oily skin and symmetrical hair loss. Dogs showing these symptoms and having scabs on their ears, strongly to point to potential hypothyroidism which can be easily diagnosed through a free thyroxine blood concentration test (a test often referred to as free T4).
Another hormonal issue that can lead to scabs on the ears is a condition known as light-responsive alopecia, hair loss due to lowered amounts of sunlight. This condition is therefore particularly popular in the the Midwest and certain northern climates that are prone to having dark winters.
Another possible skin condition that may cause crust on the edges of a dog's ears are dog allergies. Scabies and dog allergies can often be confused with one another. Just as in scabies, allergic dogs will feel itchy and they will respond by scratching when their ear tips are touched (pinnal-pedal scratch reflex).
If scabies is suspected, it's best to treat for scabies, before pursuing workups for allergies, explains veterinary dermatologist Alice M. Jeromin. If the dog responds to scabies therapy ("Ivermectin response test"), then scabies is most likely the culprit, but if the dog fails to respond, then allergies should be investigated, possibly starting with a food allergy trial.
Dog Ear Margin Seborrhea
This condition typically affects dachshunds and cocker spaniels, but any dog breed known for having floppy ears can ultimately be affected. Dog ear margin seborrhea, as the name implies, causes lesions on the edge of the dog's ears, but can be present also on the bridge of the nose. The scabs appear as waxy, yellow-gray scales that adhere to the hairs. When the hairs are removed they leave behind skin with a shiny surface.
At this time, the underlying cause remains unknown, but what is known is that dg ear margin seborrhea can be caused by Malassezia yeast or other keratinization disorders. Treatment consists of degreasing shampoos such as those containing sulfur, salicylic acid or benzoyl peroxide and other topical or oral medications to help the skin heal.
Dog Ear Edge Vasculitis
Vasculitis is a medical term used to depict the inflammation of the blood vessel's walls. This autoimmune condition is often found in dachshunds, whippets, Italian greyhounds and Chihuahuas presenting hair loss of the outer area of their ears. Being auto-immune means that the dog's immune system is inappropriately reacting to something. The condition may sometimes develop following vaccines. Treatment consists of an oral medication known as pentoxifylline, which helps improve blood flow.
There are several other causes for scabs on the edges of a dog's ears. These may include frostbite, fly strike, a condition caused by small flies landing on the dog's ear margins and biting causing black scabs, pemphigus foliaceus, dermatomyositis (ringworm), certain collagen disorders and cold agglutinin disease.
In some cases, the scabs can form because of excessive head shaking, causing the ears to violently slap against the side of the head and split open, creating cracks which bleed and form scabs. In other cases, the dog may be scratching at the ears excessively, or perhaps another dog in the household, especially a puppy, may be playing with the dog's ear tips causing annoying inflammation and infections.
Because of all these possibilities, it is a good idea to see the vet to determine the underlying cause. The vet will likely take a skin scrape which will help with diagnosis.
- Vet Rec. 2001 May 19;148(20):621-3.Value of the pinnal-pedal reflex in the diagnosis of canine scabies. Mueller RS1, Bettenay SV, Shipstone M.
- DVM360: Ear edge dermatitis: Look beyond scabies
- Merck Veterinary Manual: Ear Margin Seborrhea