Conjunctivitis in dogs is one of the most common eye problems seen in consultation and, although it usually has a good prognosis, it should not be taken lightly. If you have noticed your dog with a red eye, with discharge or rubbing its face with its paw, the membrane that lines the eye and the inside of the eyelids (the conjunctiva) is very likely inflamed.
What is conjunctivitis in dogs?
The conjunctiva is a thin mucous membrane that lines the inner surface of the eyelids and the part of the eye that is not the cornea. Its job is to protect and lubricate the eye. When it becomes inflamed, we talk about conjunctivitis: the tissue turns red, swells and produces more secretion, giving rise to that characteristic discharge.
It is not a single disease, but rather a sign that something is irritating or affecting the eye. That is why identifying the cause is so important: conjunctivitis can be mild and resolve in a few days, or be the first sign of a more serious eye problem that needs specific treatment.
Symptoms of conjunctivitis in dogs
The signs are usually quite visible and appear in one or both eyes. These are the most frequent:
- Red eye: the white of the eye and the inside of the eyelids turn red due to inflammation.
- Discharge: it can be clear and watery, or thicker, yellowish or greenish if there is an infection.
- Excessive tearing: the eye waters more than usual and the area below the eye appears damp.
- Swollen eyelids: the dog may have the eye half-closed or find it hard to open fully.
- Discomfort and itching: it rubs its face with its paw or against furniture, carpets or the floor.
- Frequent blinking or sensitivity to light in some cases.
If you notice that your dog keeps the eye closed, finds it very painful or the redness comes with changes in the cornea (whitish areas or a cloudy appearance), do not wait: it may be a more serious condition that requires prompt assessment.
Causes of conjunctivitis
The causes are very varied, and the treatment depends on them. The most common are:
- Foreign bodies: sand, dust, seeds or small grass awns that lodge under the eyelid and irritate the eye. They are very common after walks in the countryside.
- Allergies: to pollen, dust, cleaning products or certain environments. They usually affect both eyes and are sometimes related to skin diseases in your pet.
- Infections: bacterial or viral, sometimes associated with other respiratory processes.
- Environmental irritants: smoke, unsuitable shampoos, very dry air or wind.
- Eyelid and eyelash problems: poorly positioned eyelashes or eyelids that fold inwards and continually rub against the eye.
- Lack of tears: insufficient tear production (dry eye) leaves the eye unprotected and favours inflammation.
Determining the origin is key for the treatment to work, since allergic conjunctivitis, an infectious one and one caused by a foreign body are approached in very different ways.
Types of conjunctivitis
According to its cause and characteristics, it is usually classified into several types:
Serous conjunctivitis
The mildest. It presents with watery, clear discharge, a slightly red eye and tearing. It is usually due to environmental irritants or the start of an allergic process.
Purulent conjunctivitis
The discharge is thick, yellowish or greenish, which indicates a bacterial infection. The discharge tends to build up in the corner of the eye and stick the eyelashes together.
Follicular and allergic conjunctivitis
Associated with allergic reactions or chronic stimulation of the conjunctiva. It usually affects both eyes and presents with itching, redness and persistent tearing. In dogs with underlying allergies, these conditions can coincide with other problems such as otitis in dogs.
“Eyes can't wait. With a red or weepy eye, or one your dog won't open properly, it's best to have it checked soon.”
Treatment of conjunctivitis in dogs
Treatment always depends on the cause, so the first step is a veterinary diagnosis. In consultation, the eye is examined, the presence of foreign bodies or ulcers is ruled out and, if necessary, tests are carried out such as measuring tear production or staining the cornea.
From there, the most common options include:
- Eye cleaning with saline solution or specific solutions to gently remove the discharge.
- Eye drops or ointments with antibiotic, anti-inflammatory or artificial tears, as appropriate.
- Treating the underlying cause: removing the foreign body, controlling the allergy or correcting the eyelid problem.
- An Elizabethan collar to stop the dog from scratching and worsening the lesion.
It is very important not to self-medicate the animal: using leftover eye drops at home, products meant for humans or another pet's treatment can mask the problem or, in some cases, make it worse, especially if there is a corneal ulcer.
Prevention
Although it cannot always be avoided, some simple habits help reduce the risk and detect problems in time:
- Check your dog's eyes regularly and clean the discharge with a damp gauze, always from the inner corner outwards and with a different gauze for each eye.
- Avoid strong draughts, letting the dog put its head out of the car window and dusty or smoky environments.
- Keep check-ups and the vaccination and deworming schedule up to date.
- After walks in the countryside, check that no seeds or grass awns are left in the eyes.
- In breeds prone to eye problems, be extra vigilant and consult at any change.
When to see the vet
Mild conjunctivitis may seem trivial, but it is always advisable to consult if the signs do not improve in one or two days, affect both eyes or recur frequently. There are situations in which the visit should not be delayed: if the eye is very painful, the dog keeps it closed, there is abundant discharge, the cornea looks cloudy or whitish, or you suspect a foreign body has got in.
Eye problems can progress quickly, and a condition that starts as a simple irritation can turn into a more serious lesion. That is why, in the face of intense pain or a sudden deterioration in vision, the most prudent thing is to seek attention without delay; our 24h veterinary emergency service is available to assess these situations when they cannot wait.
We can help you at Clínica Veterinaria Somo
If your dog has a red eye, discharge or shows eye discomfort, at Clínica Veterinaria Somo, in Somo (Cantabria), we can examine its eye, identify the cause and prescribe the most appropriate treatment. You can contact us or call us on 942 51 00 66 to book an appointment and look after your dog's eye health.
Types of conjunctivitis at a glance
This table summarises, based on the information above, the three types according to their discharge and usual cause.
| Type | Discharge and usual cause |
|---|---|
| Serous | Watery, clear discharge; environmental irritants or the start of an allergic process |
| Purulent | Thick, yellowish or greenish discharge; bacterial infection |
| Follicular and allergic | Itching and persistent tearing; allergic reactions or chronic stimulation |
Assess each case with your vet; the right treatment depends on each animal's age, weight, health status and history.
Frequently asked questions
Is conjunctivitis in dogs contagious to people?
Most canine conjunctivitis does not transmit to people. Even so, it is advisable to wash your hands after applying the treatment or cleaning the eye and to avoid sharing towels or gauze. If there are other animals at home, ask your vet whether there is any risk of spreading it between them.
Can I clean my dog's eye with chamomile or tap water?
It is not the best option. Chamomile can irritate the eye further and tap water is not sterile. The safest thing is to use saline solution or a specific eye solution and, when in doubt, to consult before applying any product.
How long does conjunctivitis take to heal in dogs?
It depends on the cause. Mild, well-treated conjunctivitis usually improves in a few days, while those linked to allergies, infections or eyelid problems take longer and sometimes require maintenance treatment. Following the vet's instructions and completing the treatment is key to avoiding relapses.
Is a red eye the same as conjunctivitis?
Not always. A red eye is a sign that can be due to conjunctivitis, but also to other conditions such as ulcers, glaucoma or foreign bodies. That is why, with a persistent red eye, a veterinary assessment is advisable to confirm the real cause.
