Why Do Cats’ Pupils Get Big When They Attack?

If you’re wondering why cats’ pupils become huge when they attack, you’ve probably heard about Anisocoria or Spastic pupil syndrome. But what causes anisocoria and what can you do about it? Read on to find out. Often, the culprit is a cat’s irrational fear of something or someone. Fortunately, there are a few different solutions for your pet’s problem.


Your cat might have one or both pupils that are unusually large. This condition is called anisocoria, and it can affect cats, other animals, and people. This abnormality is usually temporary, but can develop into a permanent condition if not properly treated. Your veterinarian can perform an eye exam to determine the underlying cause and offer treatment options. To determine the cause of your cat’s abnormal pupil, contact your veterinarian immediately.

Anisocoria in cats can cause their pupils to be abnormally large, or even become reddish or bluish. If this happens to your cat, it might also lead to loss of vision, as well as discomfort in the eye. Your cat may also squint excessively or suffer from lethargy or vomiting. It may also be clumsy and prone to injury.

There are various causes for this condition. Symptoms of this condition include inflammation of the eye’s interior, corneal ulcers, head trauma, and glaucoma. A cat may also suffer from spastic pupil syndrome due to a virus, such as feline leukemia. Anisocoria may even result from exposure to certain chemicals or medications. If this condition affects your cat, take them to the veterinarian immediately to determine the cause.

Spastic pupil syndrome

There are many reasons why cats’ pupils can get large during an attack, but a major reason is the presence of hypertension. Cats who are overweight or older are particularly susceptible to this disease, and vets can often tell the difference by watching the cat’s eyes. Untreated hypertension can lead to retinal detachment and even blindness. To reduce your pet’s risk of developing this disease, you should take them to your vet as soon as possible.

A cat’s pupil size is a good indicator of its emotional state. In most cases, dilation occurs when a cat is excited or nervous. This excitement is often triggered by something negative, like a loud noise or an unknown house visitor. Cats with big pupils are more likely to attack or lash out in fear. Therefore, you should wait until your cat’s pupils return to normal before attempting to intervene.

Besides anxiety, big pupils also signal that a cat is frightened. If they’re very afraid, they’ll use their claws or teeth to escape. However, if they’re just excited, they may be anticipating a game or a new toy. Context is a powerful tool in interpreting feline emotions. While it’s not always possible to determine the exact reason for a cat’s dilated pupil, this behavior may help you understand if you’re dealing with a situation that involves an imminent threat to your cat.


Though the outlook for feline dysautonomia is bleak, the condition can be managed. When diagnosed in its early stages, it can often be treated through careful nursing and medical intervention. If the symptoms aren’t severe, however, they may persist for several months or years. Treatment will depend on the cause of the problem and whether the condition is reversible. If the disease is untreated, cats with dysautonomia may have ongoing health problems.

In addition to dilated pupils, other symptoms of feline dysautonomia include sluggish reflexes, diarrhoea, and urination. In addition, cats with dysautonomia may also suffer from coughing, dry nose, and a lack of appetite. Ultimately, treatment can be successful, but the resulting condition can be frustrating for the cat.

While animal researchers still don’t have a definitive diagnosis, some symptoms can suggest dysautonomia. The disease affects the autonomic nervous system and results in loss of parasympathetic and sympathetic functions. It is most common in cats but has been seen in hares, horses, and dogs. It typically affects the digestive system and the functioning of the gastrointestinal tract. Other signs include blurred vision and urinary problems, such as incomplete urination.