A closer look: Swollen Eyelids in Cats
Swelling around the eyes is uncommon in cats. Although many of the causes of swollen eyes in cats are relatively harmless, some causes can lead to permanent vision loss or blindness if left untreated. Emergency veterinary care is warranted for cats with swollen eyes, especially if they also experience difficulty breathing, collapse, vomiting, or diarrhea.
There are a wide variety of potential causes for a cat's eyes to be swollen. In general, there are three types of tissue in a cat’s eye that can become irritated and therefore swell:
- The eyelids
- The conjunctiva (the lining of the eye)
- The eyeball
Generally, irritation of these tissues are caused by several possible factors including:
- Environmental irritants, including insect stings and allergens
- Foreign objects trapped in the eye, such as dust or debris
- Traumatic injuries, including scrapes or pokes
The severity of swollen eyes in cats depends on several factors including:
- Whether the onset is sudden or gradual
- Whether the swelling affects one eye or both
- Whether there are other symptoms
In cases where onset is sudden, it is more likely that the cause is traumatic injury, an insect sting, or foreign object. In cases where the onset is gradual, an underlying eye condition, tumor, or infection is more likely.
In cases where one eye is swollen, it is more likely that a traumatic injury, insect sting, or foreign object is the cause. In cases where both eyes are affected, it is more likely an eye condition or infection.
In cases where swollen eyes are the only symptom, it is likely that the cause is local, meaning that it is only affecting the eye. Possible causes in this case include traumatic injuries, disorders of the eyelashes or eyelids, or the presence of a foreign body under the eyelid. In cases where swollen eyes are accompanied by other symptoms such as sneezing, welts, weight loss, fever, or skin irritation, it is likely that the cause is systemic, meaning that it is affecting other parts of the body. Possible causes in this case include infections, or allergic reactions.
In cases where the cat has been stung near the eye by a bee or a wasp, the severity depends on whether the cat is allergic to bee or wasp stings.
Cats who appear to have an allergic reaction to insect stings need urgent veterinary attention. Any cat with vomiting, difficulty breathing, and collapse needs emergency veterinary attention.
Testing and diagnosis
Diagnostic tools to investigate eye swelling include physical and ophthalmic (eye) examination.
Ophthalmic examination includes:
- Examination of the back of the eye using an ophthalmoscope
- Schirmer test (to identify tear production by the eye)
- Pressure testing (to determine the pressure of the eyeball)
- Fluorescein stain (to check the surface of the eyeball for damage)
Referral to a specialist may be required.
Treatment depends on the underlying cause, and may include:
- Wound care
- Antibiotics, anthelmintics, antifungals or antivirals
- Pain relief
- Dental care
- Surgery, possibly including removal of the eye
Sleepy cats or cats suddenly facing bright light often hold their eyelids partially closed. Some cats have naturally puffy eyes. Both of these circumstances can be mistaken for swollen eyes.