Why Does My Cat Have Dilated Pupils?

Even though your cat can’t communicate with you directly, it communicates through its body language and through its eyes. This is why you should pay attention to your cat’s behavior as it is an indicator of its overall wellbeing.

For example, what does it mean if your cat’s pupils are dilated? Is it trying to tell you something or is it a sign that it’s ill? Let’s find out!

Explaining the Meaning Behind Your Cat’s Dilated Pupils

Explaining the Meaning Behind Your Cat’s Dilated PupilsSince humans have domesticated cats, many of their instinctual behaviors have gone through a couple of changes. Perhaps the most relevant example is the one related to a cat’s instinctual desire to hunt.

Cats’ ancestors were animals that operated in the darkness, taking advantage of the fact that nighttime concealed them. What made it possible for cats to hunt in the darkness is the anatomy of their eyes. Cats have an outstanding night vision.

This is why cats dilate their pupils as much as possible, in order to allow the light to enter. The eyes feature a tissue known as tapetum lucidum. Thanks to this tissue, the eye is capable of absorbing and preserving the light before it reaches the retina. This is what boosts the sharpness of a cat’s vision at night.

On the other hand, during the day, a cat will contract its pupils, keeping them more closed or open, depending on the amount of light. Nevertheless, other elements can also trigger the dilation of the pupils, not solely the entry of light.

So, if you notice that your cat has dilated pupils, here are some potential explanations;

  • Fear

If your cat’s pupils are round and dilated, then this might be an indicator of fear. For instance, your cat might react in this way in the case of a thunderstorm, or anything of the kind.

  • Excitation

When your feline companion is nervous or excited, then it will most likely have its pupils dilated. This is quite common, for instance, during a game session. Still, excitement isn’t triggered by positive stimuli in most cases, but by negative ones such as anxiety or stress.

  • Aggression

When a cat stares at its prey and gets ready to attack, its pupils will most likely be dilated.

  • Satisfaction

When your feline experiences a sense of satisfaction, its pupils might dilate, and this usually happens as a reflex. For instance, when you fill your cat’s bowl with its favorite food, you might notice this.

On a different note, there are cases when your cat’s dilated pupils might be a bad sign. Evidently, if you notice this while playing with your cat, there’s nothing you should worry about. Still, in some cases, your cat’s pupils get dilated because it feels uncomfortable, anxious or stressed. So you should be wary of these situations. If your feline companion is feeling stressed, it is your responsibility as its owner to address the issue.

It’s also worth noting that each cat is different. Therefore, what is applicable in the case of one cat isn’t necessarily the case for all cats. Thus, this isn’t necessarily a sign of warning. At least not every time. This is why you should know your pet, to be able to tell whether it is feeling unwell and uncomfortable or not.

For instance, there are also specific breeds of cats that are more inclined to show dilated pupils without the presence of an underlying health problem. The British Shorthair Cat breed fits into this category.

My Cat’s Pupils Are Different Sizes: Should I Worry?

This is another question that many cat owners ask, and it is legit. What does it mean if you notice that your cat’s pupils are of different sizes? If you notice this, then it means that your cat suffers from an issue called anisocoria. Note that this is, most of the time, a symptom of an eye condition, and in some cases, it can be an emergency.

For instance, in case anisocoria happens out of nowhere, then you should treat it as an emergency situation. In this case, it is highly advisable to take your cat to the vet right away to have it diagnosed. The fastest you can do that, the fewer the chances of your cat’s vision being permanently harmed.

What is more, if you notice that your cat’s pupils are of different sizes, then this might also point out that your feline companion is suffering from one of the following illnesses: a brain injury due to trauma (such as a stroke), a nerve problem, an injury on the eye’s surface, inflammation in the interior of the eye, glaucoma, retinal disease, and in some instances, even cancer.

Health Problems Associated with Dilated Pupils

Health Problems Associated With Dilated PupilsThere are various health conditions that cats are prone to suffer from and dilated pupils represent a warning sign for some of them. If there are no stimulants in your cat’s surrounding whatsoever, and you have excluded the instances we mentioned beforehand, then your cat’s dilated pupils might be a sign of ill health.

This is the case for elderly cats, in particular. Some of the most common conditions worth mentioning are head trauma, glaucoma, eye injury or discomfort, poisoning, cancer, anisocoria, renal insufficiency, uveitis, hypoglycemia, feline leukemia virus.

Dilated Pupils and Glaucoma

When a cat suffers from glaucoma, this means that there is a heightened pressure of the fluid inside the eye. Similar to humans, cats have drainage channels. When these channels get blocked, this will lead to the accumulation of the aqueous humor. Due to this accumulation, the pressure will grow, which may lead to glaucoma or even blindness.

Dilated Pupils and Kidney Failure

As your cat grows older, it becomes more prone to suffer from kidney failure. In fact, kidney failure is one of the most commonly met illnesses for cats. Still, in some isolated scenarios, younger cats might have it as well. You cannot rule out the likelihood altogether unless you’ve assessed all the symptoms associated with the disease and your cat doesn’t have them.

The thing is that, usually, when a cat has kidney failure, it will most likely have hypertension as well. To that end, hypertension is linked with dilated pupils. Eventually, hypertension may also lead to eye problems such as retinal detachment, hemorrhage, and blindness.

Usually, kidney failure comes accompanied by other symptoms in addition to dilated pupils, such as weight loss, diarrhea, loss of appetite, apathy, pale mucous, excessive hair loss, dehydration. If you notice that some of these symptoms overlap, you should take immediate action. Renal failure is a serious condition and it requires veterinary assistance.

Dilated Pupils and Head Trauma

You should know that head trauma might lead to brain damage. Brain damage may be pointing out to damage in the autonomic nervous system as well. The autonomic nervous system is responsible for ensuring some basic functions such as those of the digestive system, the heartbeat, the pupillary response, and some others. Hence, if your cat gets hit or is injured, this may imminently lead to head trauma.

The main symptom is the dilation of the pupils, as well as noticing that your cat is acting odd. The need for treatment will depend on the situation itself. But if you know that your cat has been involved in a sort of accident, perhaps you should consider taking it to the vet to determine whether it is healthy or not.

Dilated Pupils and Retinal Detachment

Retinal detachment is, unfortunately, quite a common and serious condition. This disease means that the retina has been detached from the epithelium layer. Among the common causes leading to retinal detachment, the ones worth mentioning would be high blood pressure, as well as hyperthyroidism. Nevertheless, there are other potential causes such as trauma, an autoimmune disease, glaucoma, cancer, inflammation, toxins, and the list may go on.

When treating this condition, the vet has to assess its underlying cause. For example, in the case of cats dealing with chronic kidney disease, a diet low in protein might eventually lead to retinal detachment. In other situations, a medical professional might prescribe your feline medication for controlling its blood pressure, if this is the case.

Final Thoughts

Without a doubt, your cat’s eyes say so many things about its overall welfare, being an irreplaceable part of its body language. To that end, it is highly advisable to study your cat’s body language in order to understand your pet’s behavior and see what makes it feel anxious, frightened, excited, so on and so forth.

Most importantly, since your cat’s pupils mirror its health status, you shouldn’t overlook any unusual signs. With that in mind, as soon as you see that something’s not right, schedule a visit to the vet, to eliminate any doubts.

Please visit Kittie Cat to find out about more mysterious cat behavior!

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