What to Know About Nystagmus in Dogs

Medically Reviewed by Vanesa Farmer, DVM on December 08, 2021
4 min read

Nystagmus in dogs refers to the flickering or twitching of the eyes. In most cases, flickering eye movements are entirely normal. But they can become concerning if the movements happen when your dog's head is still.

The primary cause of nystagmus is vestibular disease, which is a disturbance in the pet's body balance.

Nystagmus can happen in both dogs and cats. Vets consider this condition a troubling sign of the pet's nervous system. 

Pets with nystagmus need urgent medical attention.

Nystagmus is a condition in which the dog's eyeballs move involuntarily and rhythmically. The movement of eyeballs can be up and down or side to side. 

Nystagmus is one of the symptoms of vestibular disease, a condition related to the vestibular system that ensures body balance. It could be a problem inside the pet's ear or brain.

Vestibular disease in dogs is more common when they grow old. For this reason, the condition is also known as old dog vestibular syndrome and canine idiopathic vestibular syndrome.

Generally, it is normal for dogs to have flickering eye movements when they are looking outside a moving car. But, dog eye twitching shouldn't happen when the dog's head isn't moving.

The two major types of nystagmus are:

  • Jerk nystagmus. It is the most common type of nystagmus. In this type, the eyeballs move in one direction slowly and then jerk back in the opposite direction with a rapid movement.
  • Pendular nystagmus. It refers to circular movements of the eyeballs caused by a defect in the ear or brain. These movements are small oscillations, like a pendulum swinging back and forth, which can be relatively slower or faster than other types.

Other common types of nystagmus are:

  • Horizontal nystagmus. It refers to side-to-side flickering of the eyeballs.
  • Vertical nystagmus. It refers to the up and down flickering of the eyeballs.

Nystagmus is more common in dogs as they grow old. Some common causes of nystagmus in dogs are:

Vestibular Disease

Vestibular disease is the primary cause of nystagmus. Various factors can lead to the development of vestibular disease, including:

  • Middle or inner ear infections
  • Toxic drugs
  • Trauma or injury
  • Hypothyroidism
  • Tumors
  • Thiamine deficiency
  • Viral infections, like canine distemper
  • Inflammation
  • Heart attacks 
  • Heart hemorrhages 

When the vet doesn't diagnose any special cause of vestibular disease, the condition is referred to as idiopathic vestibular syndrome. In such cases, the eye twitching improves with little to no medical intervention.

Congenital Nystagmus

Some puppies have nystagmus by birth, known as "congenital nystagmus." These puppies are usually blind or have other health conditions.

Blindness

In rare cases, nystagmus can also develop in blind dogs.

Dogs with nystagmus may show other symptoms too, including:

  • Loss of balance
  • Head tilting
  • A droopy face
  • Nausea or vomiting
  • Circling
  • Frequent falling on the ground
  • Standing with widely-part legs

Your dog may or may not show these symptoms as nystagmus refers to ocular movement abnormalities.

The vet may recommend you to get your dog's cerebrospinal fluid checked by a neurologist to diagnose the underlying cause of nystagmus. This process can also reveal inflammation related to an imbalance of the eyes. Some doctors also do CT scans to identify any defect in the brain leading to an imbalance of the dog's eyes.

Some vets may perform a urinalysis to find the underlying cause of your pet's condition. Other tests, like bacterial cultures and serologic testing, can also help detect any infectious object in the pet's body causing ocular movement abnormalities.

The best nystagmus treatment plan depends upon the condition's underlying cause and the severity of the symptoms. If nystagmus is caused due to viral infections, the vet treats them first. 

Since some dogs may experience anorexia and vomiting, the doctors recommend you take extra care of their food and nutrition. For such dogs, vets also suggest fluid therapy, through an intravenous (IV) fluid administration, to avoid dehydration. 

Your vet may also prescribe the proper medication for your dog's condition.

Post-treatment management of nystagmus also depends on the cause of the condition. Mostly, vets suggest a neurologic exam after two weeks of the initial treatment. This helps monitor the improvement progress in your pet. 

After the treatment, some dogs may also show secondary symptoms, such as dehydration or excessive vomiting. If your dog experiences such symptoms, the vet will address them too.

The management and recovery process may vary. But, dogs with peripheral vestibular disease (ear-related) are more likely to get better than those with central vestibular disease (brain-related).

Contact your vet as soon as you observe any signs of nystagmus in your dog.