Dog Discoveries

I am Your Dog’s Eardrum

 

Just like us, dogs have an eardrum that plays a big role in a dog’s sense of hearing. A dog’s eardrum is not readily visible since it’s set deep into the dog’s ear canal, but when this structure incurs into problems, we can sometimes recognize that something is amiss. Sometimes, the things we do with our dogs may play a role in problems with a dog’s eardrum, so it’s very important to keep this structure in mind. So today, let’s discover more about a dog’s ear drum and let’s listen to this important membrane’s story.

ear drum non perforated
Intact eardrum

Introducing Your Dog’s Eardrum

Hello, it’s your dog’s eardrum talking! If you prefer, you can call me “tympanic membrane.” This makes me sound more important, no?



As mentioned, you might not be very familiar with me as I live in the shadow, tucked deeply within your dog’s ear canal. I am simply a thin membrane that’s  stretched tight, just like a drum.

I basically separate your dogs’s external ear canal from his middle and inner ear. I play some important functions, and yes, sometimes I even get damaged, which is why you may sometimes see your veterinarian checking on me with his otoscope.

 

I am Protective

dog sense of hearing

Since I am placed in a strategic spot between the external ear canal and the middle and inner ear, I play a protective role, keeping bacteria and fungi from entering the middle ear and potentially causing a middle ear infection. Middle ear infections (otitis media) are a far cry from the average outer ear infections (otitis externa.) According to veterinarian Ernest Ward,  a middle ear infection is a serious condition that requires aggressive treatment. Sometimes middle ear infections may even progress into inner ear infections (otitis interna) which may cause deafness and loss of balance. So, yes, you must thank me if your dog is often spared from these maladies–when all goes well.

dog ear anatomyI Detect Sounds

I play a big role in your dog’s sense of hearing. When puppies are born, I am actually sealed closed so I am unable to carry sound as of yet. The ability to detect sounds starts when the puppy is about three weeks old, so from that day on I am on my way to my auditory mission. You see, I tend to vibrate when sound waves hit me. My vibrations move the small bones, known as the malleus, incus, and stapes, found in your dog’s middle ear, which then send the vibrations to your dog’s inner ear. From here, the auditory message finally reaches the dog’s brain. The reactions to these auditory messages may range from “Woohooo, my owner is grabbing my leash! to “Eeeek, fireworks! I  am so scared, I better seek shelter under the bed and stay safe!”

perforated eardrum
Ruptured eardrum

When Things Go Wrong

Remember how I said that I was a thin membrane? Well, this is my weak point. Even though I am tucked deep inside your dog’s ear canal, I am vulnerable and prone to rupturing. How can this happen? Well in several ways. Very loud noises can sometimes cause me to rupture if close enough, so this is another good reason to keep your dog away from fireworks, gun shots or air horns. I can also rupture when there are severe changes in atmospheric pressure, or more commonly, when your dog has a middle ear infection. Sometimes toxins and ear infection may be culprits. I can also perforate when instruments are inserted in the dog’s ear too deeply or if a foxtail manages to work itself through me. Fortunately, your dog will likely let you know if I am ruptured. Here are a few symptoms of a ruptured eardrum in dogs:

  • Pain. Your dog may whimper or yelp when his ear is touched or he may shake his head or paw or scratch at it. He may tilt his head or rub his ear. When the pain is intense, some dogs may become reluctant to open their jaws and this may mean that they may become reluctant to eat, especially crunchy foods like kibble.
  • Ear Discharge. If your dog develops an middle ear infection, fluid may accumulate and since it has no where to escape, it can put pressure on me causing me to rupture or tear. When this happens, a pus-like discharge, sometimes tinged with blood, may seep out into the dog’s external canal, becoming visible. Usually, when I burst, the dogs feels a bit relief from the pain as there’s no more pressure.
  • Loss of Hearing. Since I transmit sounds to the dog’s inner ear, when I rupture I can affect your dog’s ability to hear. However, you might hardly notice this, because dogs are good in compensating hearing loss by using their other ear.
  • Neurological Problems. When I rupture because of a middle ear infection, affected dogs may develop neurological symptoms. You see, the middle ear hosts several facial and sympathetic nerves, so when bad things happen there, paralysis of the facial nerves may occur causing the dog’s face and mouth on the same side to appear droopy, the appearance of the dog’s third eyelid  and the inability to blink. When the inner ear is affected too, affected dogs may start showing balance-related symptoms such as staggering, walking in circles,  nystagmus, involuntary eye movements, and lack of coordination.

When I am ruptured, it’s very important that dog owners do not try to self-treat at home as using ear medications can cause future damage to me. There are very few products that are safe (and not ototoxic) to use in a ruptured eardrum. This is why, vets thoroughly check me out before prescribing ear drops. If you suspect I have ruptured, see your vet as he can only assess whether I am still intact or not, courtesy of the handy otoscope and other helpful tests. The good news is that, if I am truly ruptured, I have the ability to repair myself. Indeed, according to veterinarian Ernest Ward, I may heal within 3 to 5 weeks and if there is a middle ear infection, medications may be needed for 4 to 6 weeks.

As seen, I am quite an important membrane that plays a big role in keeping your dog’s ears healthy and your dog responsive to surrounding sounds. So make sure to keep me in good shape. Don’t expose your dog to loud noises, don’t stick things in your dog’s ears and avoid using ear drops without seeing your vet first. Your dog and me will thank you!

Yours truly,

Your Dog’s Eardrum. Dog Pawprint

 

References:

  • VCA Animal Hospitals, Tympanic Membrane Rupture and Middle Ear Infection in Dogs, retrieved from the web on July 4th, 2016
  • Merck Veterinary Manual, Otitis median and interna, retrieved from the web on July 4th, 2016
  • Pet Education, Ear Anatomy and Hearing, retrieved from the web on July 4th, 2016

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