Deafness in cats and other hearing problems are usually associated with aging. Other causes include illnesses, neurological disorders and defective genetic makeup of the cat’s ear. Cats can compensate for small degrees of deafness. Knowledge of common symptoms will help you make an early diagnosis and seek prompt intervention. Here is more on diagnosis and treatment of deafness in cats.
Cats are widely acclaimed for their self-independence and intelligence that makes them one of the most loved pets. They have unique natural features that make them an envy in the animal kingdom, for example, they have inborn vocalization qualities. Meaning that a cat after a few weeks is self-taught on how to meow, howl or purr and doesn’t need to be taught by the mother cat. Unlike birds and others including humans who have to learn the art of language, a kitten can communicate as early as two weeks.
Another unique feature of cats is that they have a high sense of hearing. This is five times more than humans, they are also able to rotate their outer ear so as to get clearer sounds. The ears help them to spot prey, create balance and communicate. Like humans, the ear is divided in the outer, middle and inner ear.
Anatomy of the Ear
When sound waves move in the air they are captured by the pinna which channels them to the eardrum. Upon receipt, the eardrums vibrate through the ossicles. They are a ring of bones that include the stirrup, anvil, and hammer to the middle ear stimulating the oval window muscles.
The window transports these vibrations through to the eustachian tube into a fluid found in the inner ear which contains the vestibular and cochlear organs responsible for balance and hearing respectively. The fluid fuels cells and special hair receptors in the cochlea membrane which transform the vibrations to electrical impulses which are sent to the brain for interpretation by a nerve. So the process involves the outer, middle, inner, nerve and brain and damage on either can lead to deafness.
Cats have a shorter gestation period of sixty-seven days and due to the high number of kittens delivered unlike other mammals, the kittens are born deaf with the ears folded in a downward position. The closure of these canals allows for the maturity of the structures within the ear by preventing excessive ear pressure. After 3 weeks the canals open up allowing for the sense of hearing. However, there might be abnormalities that may inhibit the opening up of the ear canal leading to deafness.
Described as the inability to hear deafness can be partial affecting one ear. It can also complete also known as bilateral when it affect both ears. There are two ways that deafness can occur in cats and they include:
This occurs when there is an obstruction of sound waves. This means that they don’t reach the nerves connected to the brain.
Three weeks after birth, the ear canal is open to a level which allows for the transmission of waves. However, if the canal is narrowed it constricts the process.
Any infection of the outer and middle ear due to a tumor or a ruptured ear drum can inhibit transmission of sound waves. It can also be caused by clogging of dirt, fur and wax in the pinna or ear drum can cause this inflammation.
For this type of deafness especially if caused by tumors early diagnosis and treatment can make the process reversible.
Nerves are located in the inner ear. They are vital for transfer of the electrical impulses to the brain for interpretation. This means that if the nerves are damaged, then no auditory communication will take place. This deafness is almost irreversible.
The nerve damage may occur naturally at birth (congenital) where the nerve receptors are underdeveloped and this is further aggravated by genetic disposition or it can be acquired from the exposure to drugs or tumors.
It causes swelling of the inner ear causing a fluid buildup in the brain completely destroying the hearing process.
Causes of Deafness in Cats
Presbycusis which is an age-related disorder that usually affects mature cats from the age of ten, however depending on the breed the symptom can appear as early as the age of seven years. It affects the structures of the inner ear making them lose their vibration sensitivity. The process is gradual and not easily detected.
Trauma and accidents such as a major fall or a serious fight can affect the inner ear or the brain thus affecting the interpretation and hearing abilities.
Genetics. The presence of the dominant white gene in the DNA of some cats predisposes them to deafness. The gene causes erosion of the inner ear structures as early as five weeks. This means that there is no stimulation of the special cells vital for hearing. It mainly affects cats that are white haired with blue eyes and it seems to affect more of the long haired cats with such traits as compared to the short haired ones.
The prolonged exposure to antibiotics produces toxins that affect the hairs found in the cochlea. These hairs are important as they are the main sound receptors that allow the transmission to the brain. The toxins are also produced by chemotherapy drugs, antiseptic which are used in the pet shampoos and drugs that have been used to clean the discharges produced by the ear.
Use of ear cleaners which produce toxic chemicals when used to heal ruptured ear drum
Over exposure to loud noises- cats are highly sensitive to noise and if they are exposed to it for a very long time, it may affect the eardrum and the inner ear leading to deafness.
Symptoms of Deafness in Cats
- None responsiveness to sounds of claps, name, footsteps toys, vacuums or hisses due to damage of the cochlea.
- Loud meows and howls as it is not able to hear itself or other voices.
- Discharge from the ear that may contain pus. This occurs when there is fluid leakage from the inner ear caused by an accident or trauma.
- Scaly or pink pinna that is inflamed. This is exhibited mostly by white haired cats who are prone to such infections.
- Highly sensitive to changes in temperature and smells and this is why the cat may become very restless at night when there is a shift. Cats have a very high sense of smell, touch, and hearing since they are unable to use their auditory senses, the other two senses become highly active.
- Cats are able to move their pinnae in 180 degrees allowing them to hear very sensitive sounds, however, when deaf they tend to respond in opposite direction when called since there is minimal communication.
- Poor balance and some exhibitions of confusion due to damage of the vestibular system
- Frequent ‘zoning out’ and loss of focus.
- Excessive scratching of ears as they are able to sense that something is blocking their ears
- Rough play with other cats since they are unable to hear their growl.
- The cat may bury one of its ‘good ‘ear on the ground while exposing the other
- Frequent tilting and shaking of head or rubbing of one side of the face
- Excessive sleeping since they are not aware of loud noises that usually wake normal cats.
- Easily startled because the cat is not aware of any approaches.
How to Diagnose Deafness in Cats
- Use of BAER (Brainstem Auditory Evoked Responses) where different noises are used to evaluate the nervous impulses in the brain. This involves
- Neurological and ear examinations to identify infections, wax, and debris.
- Cats are sensitive to both high and low-frequency noises. The high frequency helps them to identify their prey from far. To test this jiggle keys or hiss when the cat is asleep and if they don’t respond then there might be a problem.
- To test low frequency gently tap a cardboard which will release a noise similar to footsteps. If the cat is unable to detect such a sound then there is a need for a thorough check up.
- Loudly clapping when the cat is facing away. Cats are usually highly alert and are startled when any noise or sudden movement is made. Their inability to respond when such a gesture is made is cause for alarm.
How to Communicate With a Deaf Cat
For completely deaf cats- Use a flashlight or laser pointers to communicate. By combining the lights with some treats to help the cat associate the light with positive outcomes and from then allowing for training other tricks. Here are more ways you can use to communicate with a deaf cat:
Using hand signals that will help to communicate to the cat such as waving the hands when standing straight to show displeasure.
- Cats use scent for olfactory communication since they may not be able to hear sounds when the owner is speaking the use of familiar scent and odors helps to create this safety.
- When cats lose their sense of hearing they may tend to stare a lot without blinking since they sense a hostile environment. As a cat owner, one should use eye contact with frequent links to make the cat feel secure.
- To create familiarity and security, a cat owner can use specific eating locations. Use of a light to signal the cat during meal time. This will resonate with the cat every time they see such a light or gesture.
- Most breeds of cats do not like water and except for Turkish Angora, Ragdoll, Abyssinian, and Burmese. The use of squirt water bottles in areas where the cat jumps. It will communicate to the cat that it is not allowed and install some behavior.
- Petting and light handling the cat acts as a way of communicating with the cat as they are able to purr and feel secure
- Use of vibrating collar and piano’s vibration as they are still sensitive to air currents and vibrations. The use of a collar bell which beams also come in handy when trying to locate the cat.
- Use of light stumps on the floor or mild claps to get its attention, the vibrations are able to communicate to the cat
- For partially impaired cats the use of a dog whistle at high frequency will help the cat identify with some sounds.
Cats are born deaf until the age of two weeks where they gain their sense of hearing. However, some breeds are genetically prone to congenital deafness and it seems to highly affect cats that have white hair and blue eyes. These include White Manx, Maine Coon, Turkish Angora, Ragdoll, Cornish Rex, Devon Rex, American Wirehair, Siberian, Norwegian Forest, European White, British short hair and white Scottish Fold.
Prevention and Treatment of Deafness in Cats
- Careful cleaning of the ears to avoid damaging the eardrum
- Recommended administered use of antibiotics to treat inflammation and infections as overuse can cause irreversible damage to the ears
- Use of sunscreen on the pinna especially on white haired cats who are at a high risk. This will help prevent inflammation or radicals that may lead to cancer.
- Deaf cats are highly vulnerable to attacks from prey. They are prone to accidents when left outdoor and so should be kept indoors most of the time.