In addition to body language, cats use their eyes to communicate with us, other cats and animals of different species. For many, the gaze of a feline is one of the most mysterious due to the characteristic shape of its pupils, but what happens when they are completely round? In general, the pupils of cats tend to resemble a vertical line, not a circle, so it is not surprising that when witnessing this change, guardians are alarmed. In this article on our site we will talk about this and explain why your cat has very dilated pupils, read on!
Meaning of the pupils of cats
Over the years the domestic cat has been evolving and adapting some of its natural habits, and an example of this is its preference for hunting. Due to the dangers that awaited them, the ancestors of today's cats were nocturnal animals that took advantage of the darkness of the night to feed and, at the same time, protect themselves from possible predators. This was possible thanks to the anatomy of its eyes, which gives this animal excellent night vision To do this, the feline dilates its pupil as much as possible with the objective of favoring the entry of the greatest amount of light. In addition, in the eyes there is a tissue called tapetum lucidum that, in short, allows light to be absorbed and retained before reaching the retina, a fact that guarantees much sharper vision at night.
During the day, the cat constricts its pupil and keeps it more or less closed depending on the amount of light. Thus, in general, we find the pupils of cats with three different shapes:
- Vertical pupil. It is contracted to avoid an excessive entrance of light, since otherwise the animal would be completely dazzled.
- Elliptical pupil. It is partially dilated.
- Round pupil. It happens when the cat's pupil is completely dilated, mainly in spaces or times of low light.
However, the entrance or not of light is not the only reason that leads the cat to contract or dilate its pupils, since on many occasions it does so as a reflex action that shows the state of mind or his he alth. We present these causes below.
Why does my cat have round pupils?
Once the function of the pupils in terms of the entry of light has been explained, something totally natural and typical of most animals, it is important to highlight that the dilation of the pupils can also be due to other factors. Thus, the answers to why your cat has dilated pupils are numerous and may be related to situations or reactions to he alth problems. Focusing on those causes related to emotions and feelings, round pupils in cats express:
- Excitation: When the animal is very excited and nervous, for example during a game session, it is common to see it with the round or elliptical pupils. However, arousal does not always occur due to positive stimuli, since it can also be caused by stress or anxiety
- Satisfaction: In situations that make him happy, the cat also dilates his pupils as a reflex action. An example might be when we fill your food bowl.
- Fear: The cat has dilated pupils and wide eyes. This is a clear sign of fear and apprehension, which can be caused by a change, a loud noise, a situation, etc.
- Aggressiveness: Cats dilate their pupils when they stare at their prey and get ready to attack, so if you look at yours in a similar attitude, he feels threatened and thinks to defend himself.
Although some of the causes that explain why a cat has round pupils are positive, it is important to highlight that this is not the usual formIn any of the cases, the dilation indicates that the animal is not relaxed, and if it happens because it is playing or practicing some activity that is good for it, we should not worry, but if much of the day we observe its dilated pupils, we should begin to think that the state of our cat is not adequate. It is possible that the animal is stressed about something, does not feel comfortable or safe, and it is our duty to find the reason that is disturbing it to treat it and restore emotional stability. To do this, we recommend visiting the article "Things that stress cats".
On the other hand, it is important to highlight that each cat is different and can develop their own forms of communication, so that dilated pupils are not always cause for alertWith this we do not mean that we should not give it the importance it deserves, but that it is essential to know our feline, its character, behavior and reactions to learn to identify a warning signal. Likewise, there are breeds of cats with a predisposition to show elliptical or dilated pupils without this implying an underlying problem, such as the British shorthair cat.
Cat with dilated pupils due to he alth problems
There are certain pathologies and conditions that show dilated pupils in their symptoms, so if the light in the environment is normal, there are no stressful or stimulating factors, but even so, the cat has round pupils, it is time to think about its he alth status, especially if it is elderly. The most common conditions and diseases that present dilated pupils as a symptom are:
- Glaucoma
- Uveitis
- Renal insufficiency
- Hypoglycemia
- Feline Leukemia Virus (FelV)
- Some types of cancer
- Poisoning
- Head trauma
- Eye discomfort or injury
- Anisocoria
In the following sections we will pay special attention to some of these problems, which also help us understand why a cat has dilated pupils and does not move.
Anisocoria in cats: one pupil larger than the other
Anisocoria in cats is the condition in which the animal presents uneven pupils, in such a way that one of them is shown more or less dilated than the other. This problem does not only affect cats, since it can also occur in other animals, including humans. In certain situations this difference may be common, however, when the condition becomes permanent, it is not normal and we must act.
To know if the cat suffers from this problem, we will look at the most common signs. In addition to the obvious asymmetry of the pupils, another symptom of anisocoria in cats has to do with the obvious eye discomfort, which is why it is common to see the affected animal scratching their eyes oftenand in different ways. Likewise, in most cases, another sign present in anisocoria is the bluish coloration of the eyes, which shows them opaque and/or reddened. It is also possible to observe the presence of legañas or abundant secretions, which do not allow the eye to open normally. All these symptoms can impair the animal's vision, so it is likely to collide with objects or furniture, walk strangely or be disoriented. Apathy and listlessness often appear as a result of general malaise.
Anisocoria is a symptom that can develop as a result of other eye diseases or problems, such as feline leukemia, corneal ulcers or uveitis. Therefore, if your cat has asymmetrically dilated pupils, you should go to the vet to find the underlying cause, since the treatment will depend on it.
Dilated pupils in cats due to glaucoma and other ocular pathologies
glaucoma in cats is a disease that involves increased pressure of the fluid inside the eye (aqueous humor). In the eyes of cats, and in ours, there are drainage channels that, if blocked, cause the aqueous humor to accumulate and, therefore, the intraocular pressure to increase, causing glaucoma and other problems derived from it, such as blindness.
However, glaucoma is not the one eye condition that can cause dilated pupils in cats. Likewise, this pathology can also appear as a consequence of another, so it is essential to review all the eye problems that may have round pupils as a symptom:
- Retinal detachment
- Uveitis
- Progressive Retinal Atrophy
- Optic nerve disorders
- Corneal injury
- Eye tumor
- Waterfalls
Cats with dilated pupils due to kidney failure
As is the case with glaucoma or anisocoria, elderly cats are more prone to kidney failure. However, it is also possible to observe this pathology in younger cats, so we should not rule it out if the symptoms coincide. Although it may seem strange to relate kidney failure to dilated pupils, the truth is that there is a good justification for it. When a cat suffers from kidney failure, it also suffers from hypertension which, in turn, causes some eye problems such as hemorrhage, retinal detachment, blindness, etc. For this reason, the cat can dilate its pupils and this sign can become another symptom of the disease.
In addition to eye problems and pupil dilation, the symptoms of kidney failure in cats that can alert them to its presence are the following:
- Apathy
- Loss of appetite
- Weightloss
- Polydipsia and polyuria (drinking and urinating a lot)
- Vomiting
- Diarrhea
- Excessive hair loss
- Dehydration
- Pale mucous membranes
If your cat has dilated pupils and is not moving, this may be the cause. Kidney failure must be treated immediately since it is a serious pathology that can end the life of the animal. For more information, check out our article "Kidney failure in cats - Symptoms and treatment" and consult your veterinarian, especially if your kitty is over 7-8 years old and has one or more of the symptoms mentioned.
Tips for cleaning a cat's eyes
Although we have seen that the causes that explain why a cat has dilated pupils are many and do not necessarily imply a lack of cleanliness, it is always recommended to maintain good hygieneof this part of the body to avoid irritation or problems caused by dirt. Here are some tips:
- If the cat produces a lot of legañas, they should be removed every morning with sterile gauze and physiological saline or chamomile, failing that.
- It is good to establish a cleaning routine of the most delicate areas, such as eyes and ears, from puppies. For adopted cats, this point is also important, always little by little and through positive reinforcement.
- If the hair around the eyes is too long, it should be trimmed to prevent it from entering the eyes and causing injury.
- If the cat shows eye discharge, inflammation, redness or excessive itching, it should be taken to the vet as soon as possible.
In our article "How to clean a cat's eyes?" we detail all the necessary material for your hygiene, steps to follow and recommendations.
