How primary secretory otitis media (glue ear) can affect the Cavalier King Charles Spaniel

Primary secretory otitis media or PSOM is the long and complex-sounding name of a canine condition that is more widely referred to among the general population as glue ear, and which can affect not only dogs but people and some other animals too.

It is a condition that, in dogs, is most commonly associated with the Cavalier King Charles Spaniel (CKCS) breed, and this is certainly by far the most common breed in which it usually occurs; however, certain other breeds of brachycephalic dog may also develop the condition too, albeit at a much lower occurrence rate than is found in the little Cavvie.

In this article, we will provide a simple, plain English introduction to this complex-sounding condition, including exploring why the condition occurs, and why the Cavalier King Charles Spaniel is at particular risk of developing it. Read on to learn more.

What is primary secretory otitis media?

PSOM affects the ears of the dog in question, and is one of several inflammatory conditions that can affect the middle ear specifically. PSOM has unknown root causes, and there is no obvious logic behind why it might affect one dog and not another, but that is commonly believed to be due to a flaw or dysfunction of the normal processes of the Eustachian tube, part of the middle ear.

This flaw can lead to either a lack of appropriate drainage of the middle ear out through the nose in the normal manner, or alternatively, an overproduction of mucous by the Eustachian tube itself. In some cases, both of these issues may occur simultaneously.

The condition can affect either just one ear or both at once, and will often progress at some point to affect both ears, even if only one is involved in the first instance.

In dogs that suffer from the condition, fluid builds up in the middle ear to the point that it causes a complete plug of thick, viscous mucous to form, which continues to grow larger and can lead to problems such as pain in the ear, compromised hearing, and loss of balance and coordination.

Why does it affect the Cavalier King Charles Spaniel specifically?

PSOM is not unique to the Cavalier King Charles Spaniel, and can also be found in various other brachycephalic breeds of dog. However, the CKCS is the breed that is the most likely to develop the condition, and this comes down to a combination of various factors and issues.

First of all, the brachycephalic face of the Cavalier King Charles Spaniel essentially means that the muzzle of the dog, and so, the space within it, is shorter than the norm, which compresses all of the various airways and other channels inside of it.

As the ears, nose and throat are closely connected to each other in terms of both their physical locations and their functions and operations, a brachycephalic muzzle also affects the shape and positioning of the mechanisms of the ear, and where the Eustachian tube drains into the nose.

The Cavalier King Charles Spaniel also has a small head in relation to their size, which is notable as few other brachycephalic breeds also share this trait, and this too is likely to be a factor in PSOM’s development. The typical long, drooping ears of the spaniel type may also play a part as well.

How can I tell if my dog is affected?

It will probably become apparent to you fairly soon if your dog is having problems with their ears, and they will likely present with a variety of symptoms that should prompt you to get your dog checked out by the vet. Some of these symptoms are also common to other ear problems and infections as well, but keep an eye out for some or all of the following:

• Tilting of the head.
• Pain or irritation of the ears that may manifest as your dog continually scratching and bothering them.
• Hearing loss or failure to respond to sounds.
• Continual or exaggerated yawning, which can occur as your dog attempts to “pop” their ears and release the pressure of the blockage.
• Pain in the neck or at the back of the scalp. This can also be a symptom of syringomyelia, which is another condition that almost exclusively afflicts the CKCS, and so again, should prompt a vet visit.

How is it diagnosed?

Your dog will need to perform a physical examination of your dog and review their veterinary history, taking into account their conformation and breed as potential markers for the condition. They will thoroughly check the ears for signs of other problems such as ear mites or minor ear infections, and may need to perform some more in-depth diagnostic tests, such as x-ray examination, or image scans of your dog’s head including a full cross-section of the ears, which may mean that your dog will need to be referred to a veterinary specialist who has access to the necessary machinery.

Can primary secretory otitis media be treated?

There are several different options available when it comes to treating the condition, and which one your vet tries out will depend on various factors, such as what will be the best choice for your own dog.

In minor presentations of the condition or as a first line attempt, your vet may prescribe medications that thin and loosen mucous, with the goal of permitting the plug of thick, viscous mucous in the ear to thin out enough to drain naturally.

However, surgical intervention may be required, which usually takes the form of a surgery called a myringotomy, a procedure that is performed under a general anaesthetic to allow your vet to make a small cut into the eardrum to flush out the Eustachian tube and physically remove the viscous mucous plug present.

An alternative approach to this is to perform a ventral bulla osteotomy, which permits the vet to again drain the Eustachian tube and remove the plug of mucous, but involves making the entry incision in the neck rather than the ear itself.

Unfortunately, none of these treatment options will prevent the condition from potentially recurring again in the future, and affected dogs may go through several flare-ups of PSOM throughout their lives.