Cats may also develop anisocoria due to spastic pupil syndrome, which is associated with the feline leukemia virus.

When pupils are different sizes, it can indicate that your cat is suffering from one of the following issues: a brain injury due to trauma (such as a fall or being hit by a car or a disease like a stroke) an injury to the surface of the eye a problem with the nerves running to the affected eye glaucoma, a very painful pressure buildup in the eye inflammation of the interior of the eye retinal disease or even cancer. “If anisocoria occurs suddenly, you should consider this an emergency situation and seek veterinary care immediately to lessen the chance that your cat’s vision will be permanently affected,” Cheryl Yuill, DVM, MSc, CVH, writes in an article on anisocoria in cats for the VCA. Anisocoria is a symptom, not a disease itself.

When one of the pupils is larger than the other, your cat has a condition called anisocoria. What if the cat pupils are different sizes?

Maybe you’ve seen this if you’ve been in a huge thunderstorm, just before your cat runs for the smallest and darkest place she can find. Wide cat eyes can also indicate abject terror. You’ve probably seen this when you take your cat to the vet and she really doesn’t want to be there. If your cat is sitting there, looking tense (with a hunched back and her tail close to her side), and her pupils are also wide, you can assume that she’s anxious about something. On the other hand, wide cat pupils may indicate anxiety. When you pull out your cat’s favorite treats, her pupils may get wide in anticipation. For example, when my cat, Bella, gets surprised, her pupils go wide and she jumps up in the air with the classic “bottle brush tail.” Wide cat pupils can also indicate excitement. Yes, it’s true: wide cat eyes can mean both excitement and fear, so you’ll have to suss out the meaning of your cat’s wide eyes by looking at what’s going on around her and her other body language cues. Photography ©aluxum | iStock / Getty Images Plus. Wide pupils signal an excited or scared cat Large cat eyes signify two emotional extremes - excitement or fear. However, if the cat pupils are narrow and your cat is relaxing on your lap and purring, you can probably guess that she’s experiencing great pleasure. The squint helps to protect her eyes from an opponent’s claws. If the cat eyes are narrow and the eyes are squinted, that’s a sign of aggression. Anger can also cause pupils to contract into slits this is usually accompanied by growling or hissing, though. You may also see the pupils contract suddenly if she’s about to “kill” her favorite toy (or your toes moving around under the blankets). Even the smell of catnip itself can cause arousal in a cat that likes the stuff. You might see this if your cat encounters a catnip mouse and prepares to attack it. These emotions can result in the sudden contraction of pupils so that they become narrow slits. Photography ©graphixchon | Thinkstock.Īrousal can be caused by many things - anger, fear and pleasure, primarily. Narrow pupils signal an aroused cat Narrow pupils mean your cat is feeling aroused by anger, fear or pleasure.

One pupil larger than other