TL;DR: A cat’s eye swollen shut is usually a sign of significant pain or injury and requires veterinary evaluation within 12 to 24 hours to prevent potential vision loss.
What does it mean when my cat's eye is swollen shut?
When a cat's eye is swollen shut, it is typically a sign of blepharospasm (involuntary squinting) caused by pain or severe inflammation. This condition can stem from various underlying issues, including:
- A corneal ulcer (a scratch on the surface of the eye)
- Conjunctivitis
- Feline herpesvirus flares
- A foreign object stuck under the eyelid
Because cats are naturally stoic, a closed eye is a significant indicator that they are experiencing discomfort.
Is my cat having a medical emergency if their eye is closed?
The urgency level for a swollen eye is Medium. While it may not be immediately life-threatening, eye conditions in felines can deteriorate rapidly, potentially leading to permanent vision loss if left untreated. You should aim to have your cat seen by a veterinarian within 12 to 24 hours. Seek care as soon as possible if the swelling is accompanied by:
- Foul-smelling discharge
- Visible blood
- Lethargy
- Refusing food
How can a photo of my cat's eye help with veterinary triage?
Capturing a clear, high-resolution photo of the affected eye can be a vital tool for your veterinary team. A visual allows a professional to assess the following:
- The color and consistency of the discharge
- The degree of eyelid swelling
- The presence of any obvious trauma or foreign bodies
This information helps the triage assistant determine whether your pet needs an urgent emergency slot or if the situation can be managed during regular business hours, ensuring your cat receives the appropriate level of care quickly.
Clinical Context (Merck Veterinary Manual)
Swollen eyelids causing the eye to be shut in cats can stem from several causes including trauma, presence of corneal foreign bodies, and neoplasia. Traumatic proptosis, often resulting from blunt trauma, involves the globe luxating from the orbit, with eyelid spasms preventing retraction, and secondary orbital hemorrhage and swelling further displacing the globe. Corneal foreign bodies, commonly organic material but also sand, metal, or glass, elicit blepharospasm and tearing, potentially leading to secondary iridocyclitis. Eyelid and conjunctival tumors, frequently malignant in cats, such as squamous cell carcinomas (especially in white cats with nonpigmented eyelid margins), adenocarcinomas, fibrosarcomas, neurofibrosarcomas, and basal cell carcinomas, can also cause swelling. If the blink response is impaired due to swelling, a temporary tarsorrhaphy is often necessary to protect the cornea. In all cases, rapid diagnosis and treatment are needed to maintain vision.
Chapter: Ophthalmology, Emergency
Source: The Merck Veterinary Manual, 11th Edition (Page 1696)