Hearing loss in dogs can occur for a variety of reasons. But thankfully, most dogs learn to cope well. To help you navigate your dog’s hearing loss, integrative veterinarian Dr. Julie Buzby explains why dogs may experience hearing loss, how your vet can assess your dog’s hearing, and how to help and support your deaf dog.
Do you have a senior dog who doesn’t respond to you when you call his or her name? Or one who no longer runs to the door when someone knocks? Sometimes a dog is simply distracted by his or her surroundings or uninterested in leaving his or her cozy bed. However, failure to react to sounds could also indicate an actual problem—the onset of hearing loss in dogs.
How does your dog hear?
Before we get into the details of hearing loss in dogs, it helps to know a little bit about the different structures that make up your dog’s ears. Beneath the ear flap (i.e. pinna), you can see the entrance to your dog’s ear. This opening leads to the J-shaped tubular outer ear canal.
As you move further down the canal, you approach the middle ear, which is located behind the tympanic membrane (i.e. ear drum). The air-filled tympanic cavity in the middle ear contains three tiny bony structures that connect to the tympanic membrane. Their job is to help transmit sounds waves from the outer ear to the inner ear.
The inner ear is housed within the skull and connects to the middle ear via a small opening called the oval window. Sound waves travel through the oval window and cause vibrations in fluid within the spiral-shaped cochlea of the inner ear. This bends the hair cells in a special sensory receptor called the organ of Corti. Those cells turn the sound wave into an electrical signal which the auditory nerve will send to the brain. Then the brain will perceive the sound.
The vestibular system
Additionally, the inner ear contains three more fluid-filled cavities—the semicircular canals, saccule, and utricle—which are part of the dog’s vestibular system. Whenever your dog moves, the fluid in these cavities also moves, which bends specialized hair cells. This creates a nerve impulse that travels to the brain to transmit information about the position of the dog’s body in space (i.e. proprioception in dogs).
While the vestibular system isn’t directly linked to hearing, it is still important to understand. Since they are located so close together and both use hair cells to create a nerve impulse, sometimes conditions that affect hearing also impact structures within the vestibular system.
What are the causes of hearing loss in dogs?
Now that you understand how a dog hears, it will be easier to discuss the various things that can go wrong with a dog’s hearing. The causes of hearing loss in dogs can be categorized into two types—congenital (i.e. usually genetic and present since birth) or acquired (i.e. occurring sometime after birth).
1. Congenital hearing loss
Normally, a puppy can hear sounds as early as two weeks of age. This is usually around the same time the ear canals open. Then by the time the puppy is six to eight weeks old, the structures in the middle and inner ears are fully developed.
However, sometimes puppies can suffer from congenital deafness. Because it typically occurs shortly after birth, this is the most common reason for loss of hearing in young dogs. It comes in two forms—cochleo-saccular deafness and neuroepithelial deafness.
Cochleo-saccular congenital deafness
You may be aware that deafness is sometimes linked to coat color or eye color. More specifically, puppies with mostly white coats (i.e. the absence of pigment) or merle or piebald coat patterns (i.e. those with patches of dilute pigmentation) have an increased risk of being deaf. Additionally, dogs with one blue eye may be deaf on that side. The explanation for this is cochleo-saccular congenital deafness.
As it turns out, the suppression of melanocytes (i.e. pigment cells) necessary to create those colors may also lead to degeneration of one of the cochlea’s layers. Since the cochlea is vital for hearing, anything that damages it leads to deafness. Dogs with cochleo-saccular deafness generally become deaf within one to three weeks of birth and may be deaf in one or both ears.
Neuroepithelial congenital deafness
Alternatively, puppies can have congenital deafness which is not related to coat pigmentation and always affects both ears. Neuroepithelial congenital deafness typically occurs due to the loss of hair cells in the cochlea in the first one to three weeks after birth. By the time a neuroepithelial deafness puppy is five weeks old, he or she completely deaf.
Since hair cells are an integral part of a dog’s vestibular system, neuroepithelial deafness can also impact a dog’s sense of balance. This results in stumbling, dizziness, and other vestibular signs.
Interestingly enough, while most cases occur in puppies as just described, an adult-onset version of heritable neuroepithelial deafness also exists. Veterinarians have noted it in breeds such as Border Collies and Rhodesian Ridgebacks around three to five years of age.
Predispositions for congenital deafness
Technically, these two types of congenital deafness can affect any dog, particularly if one of their parents was deaf or if they have excessive white coat pigmentation. However, the following breeds may be more prone to congenital deafness:
- Australian Cattle Dog
- Boston Terrier
- Bulldogs (English and French)
- Bull Terrier
- Cocker Spaniel
- English Setter
- Fox Terrier
- Great Dane
- Jack Russell Terrier
- Old English Sheepdog
- Scottish Terrier
- Shetland Sheepdog
2. Acquired hearing loss
On the other hand, acquired deafness refers to hearing loss due to outside factors like infection, trauma, obstruction, etc. Typically, acquired hearing loss is more common in adult or senior dogs. It can be broken down into two categories—conduction deafness and sensorineural deafness.
As the name might imply, conduction deafness occurs when something keeps sound waves from being properly transmitted to the inner ear. For example, the build-up of ear wax or the application of a viscous, long-acting ear drops can lead to temporary hearing loss.
Additionally, dogs with chronic ear infections (i.e. otitis in dogs) may develop conduction deafness over time. This is because the chronic inflammation associated with repeated ear infections leads to permanent changes in the architecture of the ear canal. In other words, your pup might be dealing with a much smaller ear canal. Plus, the exudate or debris that accumulates with active infections can physically impede or block sound waves.
On the other hand, sometimes a dog will be deaf due to problems with the structures of the inner ear, especially the auditory nerve or cochlea. Unlike conduction deafness, which is sometimes reversible (e.g., by the removal of waxy build up from an ear canal), sensorineural deafness is typically irreversible.
Multiple factors can be responsible for the development of sensorineural deafness in dogs including:
- Chronic middle or inner ear infections which damage the components of the middle or inner ear
- Loud noises (e.g. hunting dogs and military dogs exposed to gun shots)
- Ototoxicity (i.e. exposure to substances that are toxic to the structures of the ear)
- Drug toxicity (e.g. chemotherapy, diuretics, salicylates, aminoglycosides)
- General anesthesia (in rare cases it can lead to deafness in both ears with an unknown mechanism of action)
- Certain pet health conditions (e.g. hypothyroidism in dogs, Cushing’s disease in dogs, and cancer)
- Any neurologic condition affecting the central nervous system (e.g., meningitis, epileptic seizures in dogs, etc.)
- Old age (due to degenerative changes to hair cells and nerve pathways)
Overall, late onset age-related hearing loss tends to be the most common cause of acquired deafness in dogs. It is also one of the most common health issues in older dogs. This geriatric-onset hearing loss is also known as presbycusis and tends to occur very gradually.
This means that if your senior canine should suddenly lose his or her ability to hear, it is a good idea to look for other causes of acquired deafness. Sudden hearing loss in dogs can be triggered by most of the factors listed in this category other than old age.
What are the symptoms of hearing loss in dogs?
While discussing the causes, you may have noticed that hearing loss can be acute or gradual, in one ear or both, and occur at various ages. Thus, it makes sense that there isn’t a one-size-fits-all set of clues that a dog is experiencing hearing loss.
Signs of hearing loss in adult or senior dogs
However, there may be some subtle clues to indicate that your dog is hard of hearing. The average adult or senior dog should respond to certain sounds by directing their attention toward the sound. Or they may actively seek out the source of the noise. For example, many dogs will run to the front door when the doorbell rings. Or they might stand at attention and focus when they hear quiet noises coming from a nearby shrub.
However, dogs with hearing loss may not respond to these sounds as well as they used to. Or it might seem like they are ignoring you when you call their name. And even if dogs do respond to a sound, it may be harder for them to find its source. It can also be difficult to wake deaf dogs from a deep sleep, even if you loudly shake their treat bag.
Also, older dogs with hearing loss may be a little disoriented at times. And hearing loss in dogs can cause anxiety. Can you imagine not being able to hear someone come up from behind you? That would be quite startling when they touch you or appear seemingly out of nowhere. This same startle response can happen in dogs with hearing loss. And it may result in fear-biting, trying to run away, or anxiety, especially in new situations.
Signs of problems that lead to hearing loss
Sometimes you might also see symptoms that go along with one of the causes of acquired deafness. A dog who has an external ear infection may be scratching and shaking his or her head. And he or she might have a foul smelling discharge and redness in the ear canal. Or a dog with an inner ear infection may also show signs of vestibular disease in dogs because of damage to the vestibular center in the inner ear. These signs include a head tilt, stumbling when walking, or nystagmus (i.e. rapid eye movements).
Signs of hearing loss in puppies
Compared to adult dogs, it can be harder to notice clues of hearing loss in young puppies. Most newborn puppies won’t respond as readily to certain sounds because the structures within their ears are still maturing. However, deaf puppies that are older than six weeks may seem more vocal than their littermates. And they may play more aggressively than their siblings.
However, keep in mind that all these indications of potential hearing loss in dogs of any age are fairly subjective. Some dogs may have altered behavior due to cognitive problems rather than deafness. And dogs who can partially hear or have only lost hearing in one ear may not show many signs at all. Additionally, deaf dogs who are stressed or who are receiving information from their other senses (i.e. feeling vibrations or seeing someone at the door) may seem like they are responding to a sound when they really aren’t.
Therefore, it is best to make an appointment with your vet if you have concerns about your dog’s hearing. He or she has the ability to assess the ear canal. Then your vet can refer your dog for specialized hearing tests if needed.
What diagnostics will the vet do to check for hearing loss in dogs?
Your veterinarian will start by performing a thorough physical examination and asking questions about your dog’s medical history. He or she may ask:
- Is your pup taking any medications?
- Has he or she ever had ear infections?
- Can you recall any trauma to the head or ears?
- Has your dog taken any medication recently?
- Was he or she exposed to loud noises?
Then the vet will use an otoscope to get a better look inside both ear canals. Sometimes he or she will see debris, inflammation, foreign material (e.g., hair, grass, or a foxtail in dogs), or even ruptured tympanic membrane. Other times the ear canals will look totally normal.
To confirm your dog has hearing loss, your vet may recommend brainstem auditory evoked response (BAER) testing. This objective hearing test measures the electrical activity in the ear and in the auditory nerve pathways. It can be performed in dogs as young as 35 days of age. Some general practice vets can perform BAER testing, but most of the time veterinary specialists administer this test.
The great thing about BAER testing is that it is non-invasive and does not require sedation. Plus, movements will not affect the test results so it is okay to offer treats to your dog during the test.
To administer the BAER test, the vet will insert small needles on the ends of wires into the skin around the dog’s head and ears. Then he or she will place foam headphones inside the ear canals. The machine will produce a clicking noise in one ear and white noise in the other to help test one ear at a time. If the sounds don’t generate any electrical activity waves on the readout, this confirms hearing loss in that ear.
Is there a treatment for hearing loss?
Once the vet or veterinary specialist diagnoses your dog with hearing loss, he or she will discuss the next steps. Unfortunately, congenital deafness and sensorineural acquired deafness are generally permanent and irreversible. The only exception is that there are rare reports of partial hearing returning in cases of sensorineural deafness due to general anesthesia or ototoxicity. Also, while it won’t reverse existing partial hearing loss, using protective ear muffs can help decrease further hearing loss in hunting dogs or military dogs.
However, in cases where the hearing loss is due to conduction deafness, treatment can help reverse it. This is especially the case if it was due to debris, wax, or a foreign body obstructing the ear canal. The solution in those cases is simple—remove the thing that is blocking the ear canal.
Along the same lines, some long-acting ear treatments come in the form of a viscous medicated gel which the vet applies in the ear canals. Sometimes this can cause a degree of temporary obstructive hearing loss. Thankfully, hearing often improves again once the body absorbs the drug and any remaining debris is flushed away.
What about hearing aids for dogs?
Sometimes I have clients ask me about hearing aids for dogs. As it turns out, there are a few companies who are working on creating them. However, to date there are no practical or affordable hearing aids for dogs. Also, at this point there are not any cochlear implants for dogs like there are for people. Thus, for many dogs who are experiencing permanent hearing loss, the best thing anyone can do is help them learn to cope with it.
How can you support your dog with hearing loss?
Many dogs with hearing loss will begin to rely on their other senses to help navigate their environment. Also, your body language can provide a lot of information to your furry friend. Hand signals and other visual cues are also a great way to communicate with your deaf dog.
Puppies and adult dogs often learn these signals quickly, especially if you use small treats as motivators. However, older dogs with vision loss and hearing loss may have a harder time. Even so, there are still ways to use scent or tactile markers to help deaf and blind dogs navigate their world.
Additionally, consider these approaches to help your deaf dog:
- Walk up to a deaf dog with heavier steps so he or she can feel the vibrations of your footfalls. This helps keep him or her from being startled as easily.
- Consider using a collar that vibrates or buzzes to send a signal to your pup. However, ensure you avoid shock collars as these can cause discomfort and injury.
- Keep your dog on a leash or in a fenced in yard when going outside for bathroom breaks, walks, or playtime. This can help him or her avoid getting into a dangerous situation or getting lost.
- When in public, use a medical alert collar and/or leash with the word “DEAF” printed on them. This helps other people know to be careful not to startle your dog.
What is the quality of life like for dogs with hearing loss?
Often, the tactics we’ve discussed, plus others your vet may suggest, can help your dog adjust to being deaf. Thankfully, many dogs with hearing loss continue to have a good quality of life.
However, occasionally the prognosis is guarded or poor. This is more likely if there is a serious underlying cause present (e.g. cancer) or if the hearing loss significantly impacts your dog’s behavior. Sadly, a deaf dog can occasionally become aggressive or anxious, which can lead to biting or other issues.
Senior dog deafness may be connected to dementia
Additionally a recent study from North Carolina State University looked at the connection between hearing loss in dogs and canine cognitive dysfunction. Hearing loss is a risk factor for dementia in people. And the study indicated that the same may be true for dogs too.
This link complicates the outlook for senior dogs a bit because the signs of dementia in dogs can sometimes become difficult to manage or negatively impact quality of life. Thus, a senior dog who has hearing loss and dementia may experience more of a decline in quality of life than a dog who only has hearing loss. And a deaf dog may also be more likely to develop cognitive dysfunction as he or she ages.
Hopefully in the future, research will continue to clarify the link between hearing loss and cognitive dysfunction so we can better understand how to help our senior dogs. And maybe in time there will even be functional hearing aids or cochlear implants for dogs. But in the meantime, remind yourself that you and your dog can get through a hearing loss diagnosis.
Hope for dogs with hearing loss
At first, I know it can seem daunting to live with a deaf dog. But believe me—it gets better! There are many resources available to help you and your furry family member adjust. Before you know it, most deaf dogs will settle into the “new normal” and never look back.
Has your dog experienced hearing loss?
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