Nystagmus in dogs is a jerky eye condition that can be caused by problems in the ears or the vestibule of the brain. It is often seen in senior dogs (old dogs), and there are cases of high urgency such as brain tumors and strokes, so caution is required. Veterinarian Sato explains.
What is Nystagmus in Dogs?
Nystagmus is a jerky movement of the eyeballs. There is also physiological nystagmus that occurs when the dog follows a moving object with its eyes (photomotor nystagmus) , but if it occurs independently of the dog’s own intention, it may be related to a disease.
Pathological nystagmus is one of the neurological symptoms caused by “vestibular disease”. The vestibule is an organ that controls the sense of balance, and the causes of nystagmus can be divided into the ear side (peripheral vestibule) and the brain side (central vestibule) .
In the ear, it is caused by otitis media and inner ear, and in the brain, it is caused by encephalitis and stroke. Depending on the cause, it may be urgent, so if you see pathological nystagmus, please go to the animal hospital immediately.
It can occur in any dog regardless of breed, age, or gender, but it is often seen in senior dogs (old dogs) .
Nystagmus symptoms in dogs
Nystagmus occurs in both eyes , and the eyeballs move differently depending on the cause. Pathological nystagmus is characterized by eye movement while the head remains stationary . There are two types of eye movements: saccadic nystagmus, which has slow and fast movements, and pendulum-like nystagmus, which moves at a constant speed. In particular, “horizontal nystagmus” in
which the eyeballs move in the horizontal direction is suspected to be an ear disease, and “vertical nystagmus” in which the eyeballs move in the vertical direction is suspected to be a brain disease . However, it is not possible to make a diagnosis based on the direction alone, as some brain diseases may move horizontally.
Possible Causes of Nystagmus in Dogs
If nystagmus is seen, the veterinary hospital will perform blood tests, ear observations, X-ray (roentgen) examinations, CT/MRI examinations, etc. to identify the cause. The main possible causes and treatments are explained separately for the ear side (peripheral vestibule) and the brain side (central vestibule) .
Nystagmus caused by the vestibule of the ear
When nystagmus is caused by the vestibule of the ear (peripheral vestibule) , it is often otitis media or labyrinthitis . Otitis media is inflammation that occurs in the space called the “middle ear” behind the eardrum, and is mostly caused by otitis externa. Because it affects the nerves of the face, other than nystagmus, symptoms of eye abnormalities called Horner’s syndrome can be seen.
When otitis externa and otitis media become chronic, inflammation occurs in the space called the inner ear, which is located further back in the middle ear. Since the inner ear has the “vestibule”, “semicircular canal”, and “cochlea” that control hearing and balance , inner otitis causes hearing loss, lightheadedness, and nystagmus.
Nystagmus caused by otitis media or labyrinthine is improved by treating them. In addition, nystagmus can be caused by hypothyroidism or infectious diseases ( such as canine distemper ) . If the cause of the disorder is unknown, it is called idiopathic vestibular di
Nystagmus caused by the vestibule of the brain
If it is caused by the vestibule of the brain (central vestibule) , stroke (cerebral hemorrhage, cerebral infarction, etc.) , encephalitis (meningoencephalitis) , brain tumor, etc. are considered. Both are urgent and require early treatment.
- Pathological nystagmus occurs involuntarily
- Problem areas can be guessed from the direction of movement
- High urgency if the cause is brain
- If you see nystagmus, go to the hospital immediately.
Nystagmus can be seen due to problems in the ear or the vestibule of the brain. It is a symptom in which the eyeballs move up and down, left and right regardless of the dog’s intention, and it may be urgent, especially if there is a problem in the brain. If you notice nystagmus in your dog, take him to the veterinarian as soon as possible.