Deafness

What is deafness?

Deafness is the loss or reduction of hearing. Hearing is the ability to perceive sound waves that are transmitted through the air or other media. The ear consists of three parts: the outer ear, the middle ear and the inner ear. Each part has an important function for hearing.

The outer ear captures the sound waves and transmits them to the eardrum. The eardrum is a thin membrane that lies between the outer and middle ear. It vibrates depending on the volume and frequency of the sound waves.

The middle ear consists of three small bones: Malleus, incus and stapes. They transmit the vibrations of the eardrum to the inner ear. The inner ear contains the cochlea, which is filled with fluid. The cochlea contains thousands of tiny hair cells that convert the vibrations into electrical signals. These signals are sent via the auditory nerve to the brain, where they are interpreted as sounds.

Deafness can be caused by a disorder in one or more parts of the ear. The most common causes are

• Congenital deafness: this form of deafness is genetic and occurs at birth or shortly thereafter. It can be caused by mutations in certain genes or by environmental influences during pregnancy. Congenital deafness is often associated with a white coat color or blue eyes, especially in certain dog breeds such as Dalmatians, Australian Shepherds or Bull Terriers.
• Acquired deafness: This form of deafness develops over the course of a dog's life and can have various causes. These include:
  • Age: Hearing naturally declines with age. This is because the hair cells in the inner ear die or become damaged and can no longer regenerate. This process usually begins from the age of seven and can lead to partial or complete deafness.
  • Infections: Bacterial or viral infections can lead to inflammation of the outer, middle or inner ear. This can lead to swelling, fluid accumulation or pus formation in the ear, which can impair hearing. Infections can also lead to damage to the eardrum or the auditory nerve.
  • Injuries: Traumatic injury to the head or ear can lead to rupture of the eardrum, fracture of the ossicles or destruction of the inner ear. This can lead to sudden or gradual deafness.
  • Medication: Certain medications can have a toxic effect on the ear and cause damage to the hair cells. This is known as an ototoxic effect. Ototoxic drugs include some antibiotics, anti-inflammatory drugs, diuretics or chemotherapeutic agents.
  • Noise: Prolonged or repeated exposure to loud noises can lead to overstimulation and damage to the hair cells. This can lead to temporary or permanent deafness. Noise-related causes include gunshots, fireworks, traffic noise or loud music.

How do I recognize deafness in my dog?

Deafness in dogs is not always easy to detect as dogs are very good at adapting to their environment. Also, dogs can use other senses such as smell or sight to supplement their communication. However, there are some signs that may indicate deafness in your dog. These include:

• Decreased response to sounds: if your dog stops responding to his name, commands, toys or other sounds, this may be a sign of deafness. You can test this by standing behind your dog and making a loud noise, such as clapping your hands or using a whistle. Be careful not to touch or breathe on your dog, as they may sense your presence. If your dog does not turn around or startles, this may be an indication of deafness.
• Changed behavior: A deaf dog may behave differently than a hearing dog. For example, it may become more anxious, aggressive or restless. It may also bark or howl more frequently to attract attention. A deaf dog may also have difficulty interacting with other dogs because it cannot hear their signals.
• Altered sleep patterns: A deaf dog may sleep deeper and longer than a hearing dog as he is not disturbed by noises. He may also be harder to wake and startle when you touch him.

How do I treat deafness in my dog?

Treatment for deafness in dogs depends on the cause and extent of the condition. In some cases the deafness may be reversible, in other cases it is irreversible. The possible treatment options are:

• Drug therapy: if the deafness is caused by an infection, antibiotic therapy can help reduce the inflammation and restore hearing. If the deafness is caused by an ototoxic medication, stopping or reducing the dose of the medication may help to stop or slow down the damage to the ear.
• Surgical therapy: If the deafness is caused by injury to the eardrum or ossicles, surgical repair may help to restore or improve hearing. If the deafness is caused by damage to the inner ear, cochlear implantation can help to partially restore hearing. This is an electronic device that takes over the function of the hair cells and sends electrical signals to the auditory nerve.
• Adapting to deafness: If the deafness is irreversible or no treatment is possible, the dog and its owner must adapt to the new situation. This requires patience and understanding on both sides. Some tips for dealing with a deaf dog are:
  • Use visual cues: You can teach your dog to respond to visual cues such as hand signals or light signals. For example, you can show him that you want to praise him by clenching your fist and shaking it. Or you can show him that you want his attention by switching a flashlight on and off.