| In short : Discovering that his dog has one or two red eyes is a frequent reason for veterinary consultation. If simple conjunctivitis is often suspected by the owners, the red eye can conceal much more serious pathologies directly threatening the vision of the animal. Here are the key points to make the difference: – Conjunctivitis (benign but to be treated): It generally affects both eyes, is accompanied by clear or purulent secretions, but does not alter the deep comfort or the vision of the dog. – Signs of ophthalmological urgency (high gravity): A closed or kept half-closed eye (blepharospasm), sharp pain (the dog is rubbing his head to the ground or leaking light), an eye that changes color (opaque, blue or white appearance) or a change in the size of the pupil should alert immediately. – The classic error: self-medication. Using an old opened eye drops or a human ophthalmic ointment without diagnosis can be dramatic (for example, applying a corticosteroid on a corneal ulcer can perforate the eye). |
The dog’s eye is an extremely fragile and complex organ. Faced with a red eye, it is sometimes difficult for an owner to make sense of things between a small temporary irritation and a eye condition severe requiring surgical or medical treatment as soon as possible.
Because some eye diseases can progress to blindness (loss of sight) in the space of 24 to 48 hours, it is essential to know how to spot severity signals. This guide helps you decode the symptoms to adopt the right reflex.
1. Conjunctivitis: the most common condition
The conjunctivitis corresponds to the inflammation of the conjunctiva, the membrane which lines the inside of the eyelids and the white of the eye.
Common causes
In dogs, it is rarely of primitive viral or bacterial origin. It is most often secondary to:
- Environmental irritation (dust, smoke, wind, swimming in the sea or in the pool).
- An allergy (to pollens, mites).
- The presence of a benign foreign body (dust, blade of grass).
- A lack of tear production (dry eye).
Typical symptoms
The eye is red, the inside of the eyelids is swollen (chemosis) and flows are observed. These secretions can be transparent and aqueous (allergy/irritation) or thick, yellowish to greenish (bacterial superinfection). Generally, the dog does not show intense pain and keeps the eye open.
2. Ophthalmological emergencies: when should you worry?
Several serious pathologies share the symptom of the red eye. If you observe any of the following signs, an emergency veterinary consultation is required.
Corneal Lulcer
This is a wound on the transparent surface of the eye (the cornea), often caused by a cat’s claw, bramble or a spikelet (dry grass) lodged under the eyelid.
- The unmistakable sign: The dog keeps the eye firmly closed permanently due to intolerable pain. He flees the light (photophobia) and the eye cries profusely.
glaucoma
Glaucoma is a sudden increase in pressure inside the eye due to a defect in eye fluids. It’s an absolute emergency.
- The unmistakable sign: The eye is very red, the pupil can remain dilated (in mydriasis) even in the light, and the cornea takes on a bluish or opaque appearance. The dog suffers from a severe headache, can prostrate and refuse his food. Without treatment in a few hours, the retina is destroyed and the eye becomes blind.
luveitis
It is an inflammation of the internal structures of the eye (Luvée). It can be the sign of a more serious general disease (infection, immune disease).
- The unmistakable sign: The eye is red, painful (half-closed), and the pupil often appears abnormally small (enosis/myosis) compared to the healthy eye. The color of Liris may seem altered.
Summary table: Conjunctivitis vs Medical Emergency
| observed symptoms | Classical conjunctivitis | ophthalmic emergency |
| eye opening | Normally open or light blink. | permanently closed or kept half-closed. |
| pain level | Moderate discomfort, occasional scratching. | sharp pain, the dog moans or rubs his head. |
| Aspect of the cornea | transparent and shiny. | opaque, veiled, white or bluish. |
| pupil size | identical and reactive to light. | asymmetrical (a bigger or smaller one). |
| drainage | Fluid or purulent (yellow/green). | Mainly clear and abundant tears. |
Good reflexes while waiting for the veterinarian
If your dog’s eye is red:
- Never put human eye drops or leftover treatment: This is the golden rule. Many eye drops contain corticosteroids. If they relieve allergic conjunctivitis, they prevent the healing of an ulcer and can lead to the perforation of the eye and its permanent loss.
- Clean with saline only: Use a sterile compress (not carded cotton that leaves fibers) soaked in sterile saline to cleanse secretions from inside to outside.
- Prevent the dog from rubbing: If your dog sucks on his eye with his paw, install a collar (or an inflatable collar) immediately to prevent him from stomping the cornea with his claws.
FAQ: Your Frequently Asked Questions
What is a spikelet and why is it dangerous for the eye?
Lepillet is a dry harpoon-shaped herb that breaks away from the grasses in summer. Due to its structure, it always progresses towards the front and infiltrates frequently under the dog’s third eyelid. It rubs the cornea with each blink, creating deep and painful ulcers. Only a veterinarian can remove it using fine forceps after local or general local anesthesia.
My dog has a red blood spot in the whites of the eye, is it serious?
A bright red spot located on the white of the eye (the sclera) often corresponds to a subconjunctival hemorrhage (a small vessel that burst). This can occur after a violent effort, a brutal play, a trauma or a coughing episode. If the eye is not painful and the dog behaves normally, it is generally not an emergency, but it requires checking to rule out a clotting disorder or hypertension.
Why do dogs with a flattened face (brachycephalic) have red eyes more often?
Races like the Bulldog, the Pug or the Shih Tzu Have very shallow eye sockets, which makes their eyes “exorbited” and very exposed to external aggressions (wind, dust). In addition, their eyelids sometimes do not close completely during sleep (lagoophthalmia), which dries the cornea, creates chronic keratitis and permanent redness.