The Ear Clinic at Coastal Veterinary Dermatology

Ear disease is a very common finding in small animal practice. Most of the literature reports that between 10-20% of the total canine population will experience ear disease at some point in their lifetime and most veterinarians see this on a daily basis. The anatomy of the dog and cat ear is quite different than that of the human ear. Their ear canals are "L" shaped, with both a vertical and horizontal canal. The canals are lined with skin that has specialized glands to produce cerumin or "ear wax". The canals end with the tympanic membrane or "ear drum". The parts that we can see on the outside, the pinna or "ear flap", help to focus sound waves into the ear canals and towards the ear drum. An understanding of normal ear anatomy is vital to proper management of ear disease in small animals.

Ear disease in dogs and cats can occur in just one ear or both ears at any given time. The clinical signs seen may be only in the ears or they may be in conjunction with other lesions elsewhere on the body. It is for this reason that a thorough physical examination must be performed before focusing only on the ears. There are a multitude of reasons as to why a patient will develop ear disease.

What can cause ear issues in dogs and cats?

There are numerous underlying issues that can results in ear disease in our small animal patients. Some of them are very common, while others are quite rare. The key is that they are identified in a timely fashion so that the ear disease does not progressively become worse. Some people may feel that ears that have an excessive amount of hair may be the problem. While hairy ear canals can cause ear disease to become worse, these hairs are often not the issue. In fact, studies hae shown that hair in the canals can be protective and prevents infection in the ears. Here is a short list of the more common reasons why dogs and cats develop ear infections:
Allergic disease: Allergies are the most common cause of ear infections in dogs and cats. This can be related to environmental allergies, as well as food allergies. These can often by clinically identical. This works by causing inflammation along the ear canals leading to a secondary inection with the bacteria and/or yeast normally present in the ears.
Parasites: Parasites can cause a significant amount of inflammation in the ears, which can lead to secondary infections. One of the most common parasites found in the ear is Otodectes cyanotis, also known as the "ear mite". This can affect both dogs and cats. Other parasites include Demodex canis (Demodectic mange) and Otobius megnini (Spinous ear tick), amongst others.
Endocrine disease: Conditions, such as hypothyroidism and hyperadrenocorticism (Cushing's syndrome) can significantly alter the surface immunity in dogs, and sometimes, cats. This leads to secondary infections from the resident bacteria and/or yeast in the ears and on the skin. Proper management of the underlying condition is critical in controlling infections.
Foreign bodies: These are more common in dogs than in cats, especially in hunting dogs. This is due to their lifestyle of running through tall weeds and grass. Different objects, such as plant awns, can find their way down into the canals leading to local inflammation and secondary infection. These can be quite painful and difficult to manage.

How do I know if my pet has an ear problem?

One of the most common clinical signs seen with ear disease in dogs and cats is scratching at the affected ear. In cases where both ears are affected, the patient may scratch at both sides. Head shaking is also a common finding with ear irritation. Other signs may include rubbing the head along the floor/furniture, holding the head to one side (head tilt), an excessive build up of ear wax, a bad odor coming from the affected ear, and the prescence of blood and/or pus coming from the ear. In more severe or chronic cases, you may notice that the pet will not let you touch the ear or may cry out when the ear is manipulated. These are usually the signs that owners may notice when dealing with significant ear issues.  Over time and if the underlying issue remains untreated, the ear canals will become swollen closed and much more firm to the touch. This happens when the ear canals, which are composed of flexible cartilige, begin to mineralize and stiffen. In advanced cases, the middle ear may become involved. This is associated with the disease crossing the ear drum and affecting structures behind it. If this condition progresses along too far, a condition called end-stage ear disease may develop. In the most severe of cases, a surgical procedure called a total ear canal ablation (TECA) may be recommened. In this procedure, the external ear canals are removed surigically and the tissue is sutured closed eliminating the external ear canals. Patients will typically lose hearing on the side where the TECA is performed. The goal with good management is to prevent the condition from getting to this point.

How are ear problems diagosed?

At Coastal Veterinary Dermatology & Ear Clinic we pride ourselves on the proper diagnosis and management of ear disease. This begins with a thorough history and physical examination of your pet. There are two primary goals in mind; treating the present infection and managing the underlying condition so that the infection does not return. The history may point towards various underlying conditions, such as allergic or endocrine disease. A physical examination of all aspects of the ear will be performed. A special instrument called an otoscope will be used to examine the external ear canals and the ear drum. A sample may be collected from the external canals to look at under a microscope and determine which organisms may be causing the infection in the ear. These infections will usually include a mixture of bacterial and/or fungal organisms. In cases where ear canal stenosis (closure) is present, your pet may be prescribed medications to aid in the opening of the ear canals. It is very important to remember that most normal ear canals will have certain numbers of organisms naturally. It's only in conjuction with the correct clinical signs that treatment will be needed.

Managing ear disease

Dr. Rossi has many years of experience in managing difficult ear cases. He has lectured on ear disease on several occasions and to numerous veterinarians. Good management begins with considering the reasons as to why your pet has ear disease in the first place. This involves ruling out all of the possible predisposing issues, like allergic disease. In some cases, flushing the ears with an antiseptic or dewaxing solution may be beneficial during the treatment plan. Topical antibiotics and/or antifungals may be needed to eradicate significant infections.

If your pet has had infections over a long period of time or has a severe ear issue, an anesthetic ear procedure may be recommended. Dr. Rossi has performed a multitude of these procedures over his veterinary career. This procedure involves using state of the art video equipment, called a video otoscope, to go deep into the external ear canals. As this procedure is under general anesthesia, it allows for visualization and manipulation of the external ear that cannot be achieved in traditional otoscopy. A small camera attached to a fiber optic cable can be inserted into the ear to examine and identify any of the issues that may be contributing to the ear disease. This also allows for proper cleaning and medication administration for ear disease. There are cases where bacteria may produce an exuberant number of toxins resulting in the patient's body producing more pus than usual. A video otoscope is the best way to clean these canals out and remove all of the debris. Sometimes, small tumors or masses can be the reason for the ear issues. Using the video otoscope, these masses can be removed and submitted for analysis. The procedure itself is relatively painless as the patient is under general anesthesia. Post-operative care may include oral medication to manage swelling and/or pain associated with ear procedures. Dr. Rossi will go over any significant findings with you and devise a plan for treating the ear disease, as well as keeping it away.