# Unilateral Deafness in Dogs: Signs and What to Do Unilateral deafness in dogs means your dog has lost hearing in one ear while the other ear still works. Because dogs adapt so well, many owners never notice until something changes at home or a vet tests the hearing directly. This article explains how to spot it, what causes it, and how to keep your dog safe and happy. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - One-sided deafness often causes no obvious signs at all, because the working ear covers most daily sounds [1]. - You may notice your dog ignores calls from one side, sleeps through noises, or startles when approached from a specific direction. - Causes include inherited congenital deafness, ear infections, wax or debris blocking the canal, a ruptured eardrum, middle or inner ear inflammation, noise trauma, and age-related hearing loss [2][1]. - A brainstem auditory evoked response (BAER) test is the most definitive way to confirm deafness in one or both ears [1][3]. - Hearing loss from ear canal blockage or infection often improves once the underlying problem is treated [2]. ## What Unilateral Deafness in Dogs Actually Means Unilateral deafness is hearing loss in one ear only. The dog can still hear with the other ear, so the world does not go silent. That is exactly why it is easy to miss. Deafness can be present at birth (congenital) or develop later in life (acquired) [2]. Congenital deafness can be inherited, or it can result from damage before birth from a poisonous substance or a virus [2]. Acquired deafness develops after birth and has many possible triggers [2]. Hearing loss can also be sensorineural or conductive. Sensorineural means the inner ear or nerve pathway is affected. Conductive means sound cannot travel properly through the outer or middle ear, often because of blockage or fluid. The distinction matters because conductive causes are sometimes reversible. ## Signs Owners Notice ### Common clues at home Dogs with one deaf ear often function almost normally. They hear the doorbell, they come when called, and they seem fine. The gaps show up in specific situations. Watch for these patterns: - Your dog does not respond to sounds coming from one side, especially when the other ear is turned away or covered. - Your dog sleeps through noises that used to wake them, but only when lying on one side. - Your dog startles when you approach from a particular direction. - Your dog turns their head to position the good ear toward you. - Your dog seems to ignore you in noisy places, where the single working ear is overwhelmed. - Your dog's recall gets worse outdoors, where sound competes with wind, traffic, and other dogs. Some of these behaviors overlap with [deaf dog behavior problems](/knowledge/veterinary-medicine/behavior/deaf-dog-behavior-problems), including anxiety, poor response to verbal cues, and startle-related reactivity. ### Why it is harder to spot in puppies and groups Young animals, or those kept in a group, can copy the behavior of other dogs, which makes deafness hard to detect [2]. It becomes easier to notice once puppies are about 3 to 4 weeks old, especially if you can observe them alone, away from other dogs [2]. ### Signs that point to an ear problem instead If the hearing change came with head shaking, scratching at one ear, odor, discharge, or pain when the ear is touched, an ear infection or blockage may be involved. Those signs are covered in [dog ear infection signs: what pet owners should notice](/knowledge/veterinary-medicine/symptom-guides/dog-ear-infection-signs) and [how to tell if my dog has a ear infection](/knowledge/veterinary-medicine/clinical-methods/how-to-tell-if-my-dog-has-a-ear-infection). ## Causes and Risk Factors ### Congenital and inherited deafness Congenital deafness can be inherited or caused by damage before birth from a poisonous substance or a virus [2]. Most congenital deafness in dogs is linked to pigmentation, particularly white coat color and patterns like extreme white spotting or merle [1]. Some dogs with grayish-blue and white coat patterns are deaf [2]. Breeds commonly affected include the Dalmatian, Bull Terrier, Australian Heeler, Catahoula, English Cocker Spaniel, Parson Russell Terrier, and Boston Terrier, though that list changes over time [2]. In a study of 811 Dogo Argentino dogs, hearing status was 74.23% bilaterally hearing, 20.35% unilaterally deaf, and 5.43% bilaterally deaf, for an overall deafness prevalence of 25.77% [4]. In that breed, dogs without a patch had a significantly higher prevalence rate than patched dogs [4]. A study of 243 dogs across Bull Terriers, Australian Cattle Dogs, English Setters, and Dogo Argentinos found 81% had a normal BAER, 11% were unilaterally deaf, and 5% were bilaterally deaf [3]. Unilaterally and bilaterally deaf dogs appeared in every breed studied [3]. Not all inherited deafness is tied to coat color. A non-syndromic deafness in Beauceron dogs causes bilateral hearing loss in puppies and is not linked to coat color, with pedigree analysis suggesting autosomal recessive transmission [5]. Researchers identified a variant in the CDH23 gene, which encodes a protein in the inner ear needed to turn sound waves into nerve signals [5]. ### Acquired causes Acquired deafness can result from blockage of the external ear canal due to chronic inflammation (otitis externa) or a buildup of earwax [2]. It can also occur with a ruptured eardrum or inflammation of the middle or inner ear [2]. Hearing often returns after these problems are resolved [2]. Other acquired causes include age and noise trauma [1]. Sensory decline, including hearing loss, is nearly universal in aging dogs and is often mistaken for cognitive dysfunction or normal aging [6]. ### A note on vestibular disease Some dogs with balance problems also have hearing loss. A case report described a 15-year-old mixed-breed dog with recurrent vestibular episodes and bilateral sensorineural hearing loss with preserved high-frequency hearing in one ear, a pattern resembling human Ménière's disease [7]. That report highlights the value of checking hearing in dogs with unexplained vestibular signs [7]. If your dog has a head tilt, nystagmus, or wobbling, see [canine vestibular syndrome: differential diagnosis and management](/knowledge/veterinary-medicine/clinical-internal-medicine/canine-vestibular-syndrome-differential-diagnosis-management). ## How Veterinarians Diagnose It ### Physical exam and history Your vet starts by asking what you have noticed and when. They examine both ear canals and eardrums with an otoscope, looking for wax, debris, infection, masses, or a ruptured eardrum. They also check for neurologic signs and test how your dog responds to sound. Behavioral observation alone is imperfect. Vets closely watch how a dog responds to sounds, but young animals and dogs in groups can copy others, making deafness hard to detect [2]. ### BAER testing The brainstem auditory evoked response (BAER) test is the most definitive diagnostic tool [1]. It measures the electrical response of the hearing pathway to a click or tone delivered to each ear separately, so it can detect unilateral or bilateral deafness accurately [3]. BAER testing is how researchers classify dogs as bilaterally hearing, unilaterally deaf, or bilaterally deaf in breed studies [4][3]. BAER testing is usually done by a specialist or a clinic with the equipment. It is quick, and it gives a clear answer for each ear. ### Other tests Wideband acoustic immittance (WAI) reflectance is being studied as a way to assess middle ear function in dogs, with repeatable patterns seen in a small group of dogs [8]. This type of testing may help distinguish middle ear problems from inner ear or nerve problems, but it is not yet a routine replacement for BAER [8]. | Test | What it checks | Best use | |---|---|---| | Otoscopic exam | Ear canal and eardrum | Finding wax, debris, infection, or rupture | | Behavioral sound response | Day-to-day hearing | Screening, but easy to misread in groups or puppies [2] | | BAER | Electrical response of each ear | Confirming unilateral or bilateral deafness [1][3] | | WAI reflectance | Middle ear function | Emerging tool for middle ear assessment [8] | ## Treatment Options Treatment depends entirely on the cause. If the problem is blockage of the ear canal from chronic inflammation or wax buildup, or a ruptured eardrum, or middle or inner ear inflammation, hearing often returns once that problem is resolved [2]. Successful treatment of ear canal obstruction may improve the associated hearing loss [1]. That means the first step is often treating the ear itself. Your vet will choose the right medication and calculate the dose based on your dog's weight and health, and on what is found during the exam. See [dog ear infection signs treatment](/knowledge/veterinary-medicine/clinical-methods/dog-ear-infection-signs-treatment) for how ear infections are typically managed. For inherited congenital deafness and most other forms of sensorineural hearing loss, treatment is generally not available [1]. In those cases, the focus shifts to management, safety, and training. If your dog has balance episodes along with hearing loss, treatment is supportive and aimed at the underlying cause. In the reported Ménière's-like case, the dog improved with supportive care but had multiple relapses over several years [7]. ## Recovery, Outlook, and Long-Term Management ### What to expect If the cause is conductive and treatable, hearing may improve within days to weeks after the ear problem clears [2]. If the cause is congenital or sensorineural, the hearing loss is usually permanent [1]. Most one-sided deaf dogs live full, normal lives. The outlook is good as long as you adjust how you communicate and keep your dog out of risky situations. ### Training a dog with one working ear - Pair every verbal cue with a hand signal or body movement. Your dog will learn to watch you. - Train facing your dog so the working ear is toward you when possible. - Use a flashlight, a hand wave, or a vibration collar to get attention at a distance. A vibrating collar is a cue device, not a punishment tool. - Practice recall in quiet places first, then add distractions slowly. - Keep a long line on your dog in unfenced areas until recall is reliable. - Teach a "check in" behavior where your dog looks at you often on walks. ### Safety at home and outdoors - Never let a one-sided deaf dog off leash near traffic, even if recall is strong. - Approach from the side your dog can hear, or stomp on the floor so vibration announces you. - Do not wake a sleeping dog by touching them suddenly. Call, then touch gently. - Use a bell on your own keychain or a light tap on the floor to signal your arrival. - Tell houseguests and children how to get your dog's attention without startling them. - Keep identification current. A deaf dog who bolts may not hear you calling. ### Senior dogs Sensory decline is common in aging dogs and is often mistaken for cognitive dysfunction or normal aging [6]. If your older dog seems "stubborn" or "confused," ask your vet to assess hearing and vision directly [6]. Managing sensory loss well can improve quality of life and the bond you share [6]. ## Prevention You cannot prevent inherited congenital deafness, but you can reduce some risks. - Ask breeders about BAER testing. Because congenital deafness is heritable and often linked to pigmentation, testing parents and puppies gives you real information [1][4]. - Treat ear infections early. Chronic otitis externa and wax buildup are reversible causes of hearing loss, and prompt treatment protects hearing [2]. - Protect against loud noise. Noise trauma is a known cause of acquired hearing loss [1]. - Keep up with wellness exams, especially for senior dogs, so hearing changes are caught early [6]. - If you are choosing a puppy from a breed with high deafness rates, ask for BAER results for the litter [4][3]. ## Limitations and When to Contact a Veterinarian No article can tell you what is happening in your dog's ears. Individual cases need a veterinarian who can examine your dog and, when needed, run a BAER test. Contact your veterinarian the same day if you notice: - Sudden hearing loss in one or both ears. - Head shaking, ear scratching, discharge, odor, or pain when the ear is touched. - A head tilt, circling, nystagmus, or wobbling that started suddenly. - A swollen or bloody ear flap. Seek emergency care now if your dog: - Cannot stand or walk. - Has a seizure. - Collapses or seems to lose consciousness. - Shows sudden severe pain or a rapidly swelling ear. Schedule a routine visit if you have noticed a slow change in how your dog responds to sound, especially if your dog is a breed with higher deafness rates or is getting older. ## Frequently Asked Questions ### Can a dog hear normally with one deaf ear? Yes, most dogs with one deaf ear hear well enough for daily life. The working ear picks up most sounds, so the dog may seem completely normal at home. Problems show up mainly in noisy places or when sound comes from the deaf side. ### How can I tell which ear is deaf? You usually cannot tell at home with any confidence. A BAER test checks each ear separately and gives a clear answer for both [1][3]. Your vet can also look for ear canal or eardrum problems that might explain one-sided hearing loss [2]. ### Will my dog's hearing come back? It depends on the cause. Hearing often returns after blockage, wax buildup, a ruptured eardrum, or middle or inner ear inflammation is resolved [2]. For inherited or sensorineural deafness, treatment is generally not available and the loss is usually permanent [1]. ### Is one-sided deafness painful for my dog? Deafness itself is not painful. If your dog has an ear infection, a ruptured eardrum, or inflammation, those conditions can hurt, and treating them often restores hearing [2]. Signs like head shaking, scratching, or yelping when the ear is touched point to pain instead of deafness alone. ### Should I use a vibrating collar on a deaf dog? A vibrating collar can work well as a attention cue when paired with training, and many owners find it helpful for recall. It should signal your dog, never punish them. Ask your veterinarian or a trainer experienced with deaf dogs to help you introduce it safely. ### Can I prevent my dog from going deaf in one ear? You cannot prevent inherited congenital deafness, but you can lower the risk from some acquired causes. Treating ear infections and wax buildup early protects hearing, and limiting loud noise exposure helps too [2][1]. For breeds with high deafness rates, ask about BAER testing before breeding or buying [4][3]. ## Related Articles - [Deaf Dog Behavior Problems](/knowledge/veterinary-medicine/behavior/deaf-dog-behavior-problems) - [Dog Ear Infection Signs: What Pet Owners Should Notice](/knowledge/veterinary-medicine/symptom-guides/dog-ear-infection-signs) - [Dog Ear Infection Signs Treatment](/knowledge/veterinary-medicine/clinical-methods/dog-ear-infection-signs-treatment) - [How To Tell If My Dog Has A Ear Infection](/knowledge/veterinary-medicine/clinical-methods/how-to-tell-if-my-dog-has-a-ear-infection) - [Canine Vestibular Syndrome: Differential Diagnosis and Management](/knowledge/veterinary-medicine/clinical-internal-medicine/canine-vestibular-syndrome-differential-diagnosis-management) - [How To Check If My Dog Has Ear Infection](/knowledge/veterinary-medicine/clinical-methods/how-to-check-if-my-dog-has-ear-infection) - [Sudden Deafness in Dogs: Causes and What to Do Next](/knowledge/veterinary-medicine/symptom-guides/sudden-deafness-in-dogs-causes) - [Deafness in Older Dogs: Causes, Signs, and What to Expect](/knowledge/veterinary-medicine/senior-and-chronic-care/deafness-in-older-dogs-causes-signs) - [Congenital Deafness in Dogs: Causes, Testing, and Care](/knowledge/veterinary-medicine/symptom-guides/congenital-deafness-in-dogs) ## References 1. [Deafness in Animals - Ear Disorders](https://www.merckvetmanual.com/ear-disorders/deafness/deafness-in-animals). Merck Veterinary Manual. 2. [Deafness in Dogs - Dog Owners](https://www.merckvetmanual.com/dog-owners/ear-disorders-of-dogs/deafness-in-dogs). Merck Veterinary Manual. 3. [Evaluation of the occurrence of canine congenital sensorineural deafness in puppies of predisposed dog breeds using the brainstem auditory evoked response](https://pubmed.ncbi.nlm.nih.gov/27993097/). Acta veterinaria Hungarica, 2016. 4. [Congenital sensorineural deafness in Dogo Argentino dogs: Prevalence and phenotype associations](https://pubmed.ncbi.nlm.nih.gov/33870537/). The Veterinary record, 2021. 5. [A CDH23 missense variant in Beauceron dogs with non-syndromic deafness](https://pubmed.ncbi.nlm.nih.gov/36308003/). Animal genetics, 2023. 6. [Sensory Decline: Real-World Tactics for Managing Vision and Hearing Loss](https://pubmed.ncbi.nlm.nih.gov/41444090/). The Veterinary clinics of North America. Small animal practice, 2026. 7. [Case Report: Recurrent vestibular episodes in a dog resembling Meniere's disease](https://pubmed.ncbi.nlm.nih.gov/42712380/). Frontiers in veterinary science, 2026. 8. [Normative wideband acoustic immittance patterns for middle ear evaluation in dogs](https://pubmed.ncbi.nlm.nih.gov/36154068/). JASA express letters, 2022. ## Further Reading - [Merck Veterinary Manual: Dog Owners](https://www.merckvetmanual.com/dog-owners) - [Cornell Richard P. Riney Canine Health Center: Canine Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-information) - [American Veterinary Medical Association: Pet Care](https://www.avma.org/resources-tools/pet-owners/petcare)