Skip to Content

5 Reasons Why Your Dog Suddenly Has A Lazy Eye + 7 Tips

Why Does My Dog Suddenly Have A Lazy Eye

Yesterday your dog caught your gaze. You two shared a moment of unconditional unspoken love and affection.

But today when they looked you in the eye again, you noticed something weird. 

One of their eyes was looking in a different direction. Kind of what chameleon’s eyes are able to do. 

And that got you thinking,

“What happened to my dog’s eye? Is this a lazy eye? Does it hurt?”

This article holds the answers to your questions. 

Keep reading to discover:

  • 5 reasons why your dog suddenly has a lazy eye.
  • 7 tips on what you can do if your dog has this condition.
  • What your dog’s middle and inner ear have to do with having a lazy eye.
  • A very simple and easy exercise to help your dog strengthen their eye muscles.
  • How a lazy eye occurs, and what goes on behind the scenes to make eyes work properly.
  • And so much more…

Why does my dog suddenly have a lazy eye?

Your dog suddenly has a lazy eye due to various factors, such as injury or trauma; vestibular diseases affecting the brainstem; tumors or polyps; otitis media-interna; and hydrocephalus. If you notice your puppy having a lazy eye, it could be inherited.

What is a lazy eye?

Dogs, just like humans, can be cross-eyed. This is rare in dogs, but some breeds are more prone.

Lazy eye is an eye disorder. The eyes look in different directions at the same time.

In medical terms, this is called strabismus.

How lazy eye occurs

Usually, a dog’s eyes move together in every direction. 

But what happens behind the eyes?

In mammals, the eyeballs have 6 muscles that make the eye move. The muscles are grouped into the following:

Rectus muscles

These are made up of inferior, superior, medial, and lateral.

The first two enable the eyes to move up and down. The last two make the eye move from side to side.

Oblique muscles

These are made up of inferior and superior oblique muscles. These enable the eyes to move in a circular motion (clockwise and anticlockwise).

Retractor muscles

These muscles do not control the movements of the eyeball. Instead, these enable the eyelids to move. 


When these muscles are working fine, the eyes work normally. They move at the same time and in the same direction.

But when one or more muscles malfunction, it leads to a lazy eye. Or, in the case of retractor muscles, malfunction leads to a dog’s lazy eyelid.

Your dog won’t feel any pain or discomfort. But the underlying reasons for the lazy eye might lead to other symptoms.

A lazy eye is further categorized according to the misalignment of the affected eye:

  • Hypertropia – the eye’s gaze stays upwards.
  • Hypotropia – the eye’s gaze stays downwards.
  • Convergent – the eye’s gaze is toward the nose.
  • Divergent – the eye’s gaze is toward the edge of the face.


The most obvious sign of this condition is when your dog’s eyes look in different directions. However, there are other dog’s lazy eye symptoms:

  • One or both eyes is/are affected.
  • Difficulty to focus both eyes on the same thing.
  • Controlling one eye but losing control of the other.

Now let’s find out how a dog gets a lazy eye…

5 reasons why your dog suddenly has a lazy eye

#1: Inherited

Your dog’s sudden lazy eye could be inherited.

Some dogs are more prone to this eye disorder. Including:

  • Akita.
  • Shar Pei.
  • Irish Wolfhound.
  • Golden Retriever.

Pugs can also develop a lazy eye. Boston Terriers, on the other hand, can inherit a lazy eye. Particularly the divergent type.

These dogs inherit the weak muscles that cause one or both eyes to move involuntarily. 

Some dogs exhibit this disorder at birth. While others develop it later on.

#2: Vestibular system problems

Vestibular Disorder Causing Lazy Eye In Dog

Your old dog’s lazy eye results from some problems with their vestibular system.

What is the vestibular system?

Your dog can stand without falling over. That’s thanks to their vestibular system.

It has sensors located in the middle and inner ear. The control center is at the back of the brain.

Here’s how things work:

Let’s say your dog is standing and looking ahead. The balance sensors detect this position of the head.

The information is converted into electrical signals sent to the brain.

The control center receives this information. Then it sends a message to the body to keep the dog upright.

And when your dog moves their head, the control center sends messages to the muscles controlling the eyes. The brain tells the muscles to change the eyes’ position according to the head’s position.

Trouble is on the horizon when there are problems with the vestibular system. Vestibular disease can lead to a lazy eye. Symptoms include:

  • Nausea.
  • Circling.
  • Head tilt.
  • Falling over.
  • Wobbliness.
  • Jerking eye movements (nystagmus).

Vestibular disease is more common in older dogs. That’s why the condition is also called old dog vestibular syndrome.


The causes of vestibular disease vary. But these could be:

  • Trauma.
  • Hypothyroidism.
  • Tumors or polyps.
  • Inner ear infections.
  • Damage to the skull.
  • Antibiotic side effects.
  • Diseases affecting the vestibular system.

If the cause is unknown, it is called idiopathic vestibular syndrome.

#3: Injuries

An injury can lead to your dog’s sudden lazy eye.

In particular, injuries to the head or trauma to the eyes are dangerous. These injuries result from falls or car accidents.

A lazy eye can be a side effect of these. 

In addition, fracture in the zygomatic bone leads to a severe lazy eye. 

This bone – located below the eye – connects the cranium with the jawbone. 

#4: Tumors

Tumors can cause your dog’s sudden lazy eye. Particularly tumors that affect the eyes, the nerves to the eyes, or the brainstem.


Some tumors grow close to the eyeball or inside the eye. These put pressure on the eye muscles.

And when this happens, the muscles can’t work as they should. Thus, the eye moves abnormally.


The brainstem is responsible for the sense of balance. It is also the source of the nerves that control the eyes’ movement.

If tumors grow in the brainstem, it affects the dog’s balance and could lead to a lazy eye.


Orbital tumors affect the eyeball in such a way that it protrudes outward. As a result, the conjunctiva, cornea, and eyelid swell.

Orbital tumors also make the affected eye unable to move with the other eye.

#5: Hydrocephalus

Another possible cause of a lazy eye is hydrocephalus.

It can affect any dog but is more common in puppies.

Hydrocephalus refers to fluid buildup within the brain.

In this study, the authors observed 564 dogs diagnosed with hydrocephalus. They found out that 11 breeds were at significantly high risk.

These breeds were the following:

  • Pug.
  • Maltese.
  • Pekingese.
  • Toy Poodle.
  • Chihuahua.
  • Pomeranian.
  • Lhasa Apso.
  • Cairn Terrier.
  • Boston Terrier.
  • English Bulldog.
  • Yorkshire Terrier.

Another study on hydrocephalus observed that a lazy eye is a common symptom. The excess fluid in brain cavities puts pressure on the eyes.

The authors also observed that divergent strabismus (looking in different directions at the same time) occurred in many brachycephalic breeds.

Bonus: Otitis media-interna

Otitis media-interna is inflammation of the middle ear (media) and the inner ear (interna).

Clinical signs depend on the severity. But the following are some symptoms:

  • Head tilt.
  • Vomiting.
  • Head shaking.
  • Refusal to chew.
  • Swinging back and forth.
  • Discharge in the ear canal.
  • Pain when opening the mouth.
  • Pawing/scratching the affected ear.
  • Inflammation of the gums, tonsils, or throat.
  • Leaning or rolling toward the direction of the affected ear.
  • Reluctance to move or preference for a crouched position.

Inflammations in the middle and inner ear are usually caused by bacterial infections. But there are also other causes, such as:

  • Mites.
  • Yeast.
  • Trauma.
  • Tumors and polyps.
  • Too much cleaning of the ear.
  • Foreign bodies (for example, foxtail).

Some dog breeds are at high risk, including:

  • Cavalier King Charles Spaniels.
  • Cocker Spaniels and other long-eared breeds.
  • Poodles having inflammation of the ears or throat.

7 tips on what to do when your dog suddenly has a lazy eye

#1: Exercise the (inherited) lazy eye

The treatment for your dog’s lazy eye largely depends on the cause of it. Thus, it’s important to get your dog to the vet to rule out medical problems.

However, there is no need for treatments if:

  • A lazy eye is inherited.
  • There are no underlying conditions.

Even without treatments, your dog’s life will not suffer.

Here’s a video of Magic, a Great Dane with a lazy eye. According to his furdad, it happens about once a week. Then it heals by itself.

What’s to be done is to allow your dog to adjust. The vet can also recommend some exercises to strengthen your dog’s eye muscles.

One example is tracking the finger exercise. Here’s how it works:

  • Hold a finger in front of your dog’s face.
  • Move the finger toward their nose.

And that’s it. It’s very simple, right? You and your dog can do it anytime, anywhere. No special equipment needed.

But this is a very handy exercise. It helps to strengthen the weak muscles of the affected eye.

Be patient, though. It will take time to see results.

Note: An inherited lazy eye is a cosmetic concern. It means there will be no long-term effects for your dog.

#2: Immediate treatments for injuries

If an injury leads to a lazy eye, the vet will first address the immediate medical needs.

It’s important to get the dog stabilized. After that, the vet will discuss what to do with the lazy eye.

Some causes of a lazy eye affect the eye only. Most of the time, this is not life-threatening.

However, some causes need immediate medical care.

In some cases, your dog experiences nausea or vestibular problems. The vet may administer medications if needed.

Anti-inflammatory medications are also helpful.

#3: Clean ears with care

Believe me, some dog parents get over the top when cleaning their dog’s ears.

What’s best is routine ear cleaning. It helps decrease the possibility of infection. Professional teeth cleaning also helps reduce infection of the middle and inner ear.

Also, avoid reaching into the depths of your dog’s ears. This makes any cleaning tools with pointed tips are a no-no.

However, many dog parents are using Q-tips because they don’t realize it’s risky.

That’s why the American Kennel Club (AKC) advises against using Q-tips. And informs dog parents of the potential risks. One of which is pushing the dirt farther into the ear.

A dog’s ears are not like greasy pans that you have to scrub hard. You just clean the outer part of the ear using a vet-recommended solution.

Here’s a tutorial for cleaning your dog’s ears the right way:

#4: Periodic monitoring

As I’ve mentioned, treatments are generally not needed for inherited lazy eye.

However, periodic monitoring is important. This is just an additional step in ensuring your dog’s welfare.

Or you can ask your vet to check on your dog’s eyes during a routine checkup.

Doing so will help you sleep better at night, knowing your dog is okay.

#5: Treating the underlying disease first

Sometimes underlying diseases are to blame for your dog’s lazy eye. To address the lazy eye, the vet will treat the disease first.

Treatments depend on the severity of tumors or hydrocephalus.

Let’s look at hydrocephalus. The fluid that accumulated within the brain cavities must be drained. Diuretics, or water pills, and anti-inflammatory medications may be needed.

Once the disease is treated, the problem will be gone.

But if the disease is not treated, it may damage the eye muscles. 

And the only solution is…

#6: Surgery or therapy

Dog Eye Surgery

Surgery is the best option if your dog is not responsive to medical treatments.

It may be the answer to treat the following conditions/diseases:


In dogs with hydrocephalus, the accumulated fluid is surgically drained.

But if this is not possible, then shunting is done. Shunting is creating a passage to allow fluid movement from one part of the body to another.

Surgical shunting is usually the treatment for congenital hydrocephalus.

In special cases, long-term therapy is needed. Particularly in cases where the fluid is not drained.

Otitis media-interna

Surgery will be given to dogs that have:

  • Fluid buildup in the middle ear
  • Tumors or cancers in the middle ear
  • Infection to the bone surrounding the ear


In orbital tumors, it’s vital to reduce the possibility of recurrence. Sometimes it’s necessary to remove the orbital mass and all orbital tissues.

One downside is that the surgery will alter the appearance of your dog. But on the other hand, surgery and chemotherapy may prolong survival time.

Sometimes tumors regrow. For prevention, have your dog checked regularly.

For eyelid tumors, your vet will take a biopsy. More often than not, surgery is needed. This is because eyelid tumors are irritating and disfiguring.

#7: Home care

Unfortunately, one can’t prevent the development of a lazy eye. 

Sometimes it comes unexpectedly. Like when your dog has an injury.

Or your dog comes with a lazy eye when you first got them from the breeder.

Having a lazy eye could be disorienting. And it might frighten them, too.

So make sure their environment is comfortable. And help them recover fast.

Here are some ideas for you:

  • Assign members of the household to monitor your dog.
  • Follow the vet’s instructions down to a T. Administer the medications correctly.
  • Provide a lot of light at home. This helps tell them the distance and position of things around them.
  • Keep them away from the stairs. Going up and down puts them at risk of falling or hurting themselves. Use a baby gate if you have to.
  • Keep your dog safe at all times. This means dog-proofing your home. Ensure there are no sharp corners or things that could hurt your dog.

And lastly, have lots of patience. At this point in their lives, you are your dog’s guiding light.

With your help, your dog will be good as gold.