TL;DR: Redness in a cat's eyes is a sign of inflammation that typically requires a veterinary exam within 24 hours, though immediate emergency care is necessary if your cat shows signs of pain, cloudiness, or pupil changes.
What does it mean if the whites of my cat's eyes are red?
Redness in the whites of your cat's eyes (the sclera) is a sign of inflammation or irritation. This condition, often referred to as 'red eye,' occurs when blood vessels in the eye become enlarged. It can be caused by a wide range of issues, from simple allergies and conjunctivitis to more serious underlying conditions like feline herpesvirus, glaucoma, or corneal ulcers. Because cats are masters at hiding discomfort, redness is often one of the first visible signs that something is wrong.
Is redness in my cat's eyes considered a medical emergency?
- The urgency level for eye redness is generally Medium, meaning you should schedule a veterinary appointment within 24 hours.
- Eye issues can progress rapidly and may lead to permanent vision loss if treatment is delayed.
- Seek emergency care immediately if the redness is accompanied by visible cloudiness or a change in pupil size.
- Immediate attention is required if your cat is squinting, rubbing, or pawing at the eye in obvious pain.
How does sending a photo help a veterinarian triage my cat's red eye?
- A clear, well-lit photo allows a professional to assess the severity of the inflammation remotely.
- Photos help veterinarians identify foreign bodies, signs of trauma, or specific types of discharge.
- This visual information helps prioritize your cat's case, ensuring they receive the appropriate level of care as quickly as possible.
Clinical Context (Merck Veterinary Manual)
In cats, redness in the eye often manifests as a congested and red conjunctiva, indicating anterior uveitis (iridocyclitis). This condition is frequently associated with systemic diseases such as feline infectious peritonitis, toxoplasmosis, feline immunodeficiency virus, and feline leukemia virus. Other pathogens like feline herpesvirus 1, Chlamydia, and Mycoplasma can cause acute and recurrent conjunctivitis. Anterior uveitis presents clinically with photophobia, pain, blepharospasm, corneal edema, reduced intraocular pressure, and miosis. Ocular lesions associated with feline infectious peritonitis commonly include retinal changes such as cuffing of the retinal vasculature, granulomatous changes, retinal hemorrhage or detachment, and uveitis. Given the potential for systemic involvement, prompt veterinary attention is crucial.
Chapter: Ophthalmology
Source: The Merck Veterinary Manual, 11th Edition (Page 1699)