Canine Conjunctivitis: How to Recognize Symptoms and Act Appropriately

At first, red eyes in dogs often seem harmless. But there can be many underlying causes for a red or watery eye—from simple irritation to an eye condition requiring treatment. That is why it is important to recognize the typical signs of conjunctivitis and not ignore changes in the eye.

What is conjunctivitis in dogs?

With conjunctivitis, medically known as conjunctivitis, the conjunctiva of the eye becomes inflamed. This is a mucous membrane that, among other things, lines the inside of the eyelids.

Conjunctivitis is one of the more common eye conditions in dogs and can affect one or both eyes. The inflammation can occur independently or develop as a side effect of another illness.

Important: A red eye does not automatically mean that it is conjunctivitis. Other eye diseases can also cause similar symptoms. That is precisely why the cause should be determined as clearly as possible.

Conjunctivitis in dogs: Typical symptoms

Conjunctivitis in dogs can manifest through various changes in the eye. Red and watery eyes are particularly common. The conjunctiva can also appear swollen, and discharge may form.

Your dog's behavior may also change. If the eye itches or is painful, it may blink more frequently, squint, or try to rub it with its paw.

Typical symptom	How it may manifest
Reddened conjunctiva	The mucous membrane around the eye appears significantly redder than usual.
Watery eyes	The eye produces increased tears, which may run down the fur below the eye.
Eye discharge	Watery, mucous, or yellowish discharge may form in the eye.
Swollen eyelids	The lids may be swollen and partially cover the eye.
Frequent blinking	Your dog blinks noticeably often or squints the affected eye.
Rubbing the eye	In the event of itching or an uncomfortable feeling, your dog may try to rub its eye with its paw.
Sensitivity to light	Bright light can be uncomfortable, causing your dog to keep the affected eye closed more often.

Not every one of these symptoms has to occur. The severity of the symptoms can also vary. Especially in cases of severe pain, significant clouding of the eye, or if your dog keeps the eye closed continuously, one should not assume it is just a simple case of conjunctivitis. In these cases, a prompt veterinary examination is important.

Causes of conjunctivitis

Conjunctivitis can have many different causes. For example, external irritants such as dust, sand, or drafts play a role. A small foreign object that gets into the eye can also irritate the sensitive conjunctiva.

Additionally, allergies as well as infections with bacteria, viruses, or fungi are potential triggers. In some dogs, anatomical features also favor the development of conjunctivitis. These can include, for example, certain eyelid abnormalities or hairs that grow in the wrong place and permanently irritate the eye.

A dry eye can also be associated with conjunctivitis. Therefore, especially with recurring complaints, it is important not only to treat the inflammation itself but also to look for its cause.

Risk of infection with conjunctivitis

Whether conjunctivitis in a dog is contagious depends on its cause. If the inflammation is caused by dust, a foreign object, or an allergic reaction, there is no risk of contagion.

It can be different with an infection caused by pathogens. Bacterial or viral diseases can generally be transmissible. Therefore, whether and how contagious a specific conjunctivitis is cannot be judged solely by the red eyes.

If your dog has contact with other dogs and simultaneously shows clear eye problems, it makes sense to avoid close contact with other animals as a precaution until a veterinary diagnosis is made.

Treatment and supportive measures

The right treatment depends on what triggered the conjunctivitis. In the case of irritation from dust or a foreign object, a different treatment is necessary than for a bacterial infection, an allergy, or a dry eye.

A veterinary examination can therefore clarify what is behind the symptoms. Depending on the cause, special eye drops or eye ointments may be used. For bacterial infections, antibiotic preparations may be necessary, while for allergy-related inflammation, a different therapy may be appropriate.

At home, you can mainly support your dog by making sure the eye is not subjected to further irritation. If possible, prevent it from scratching or rubbing the eye with its paw. You can carefully clean the eye area with a clean, damp cloth if necessary.

However, you should not use medications or eye drops from your own human first-aid kit on your own initiative. The eye is sensitive and incorrect treatment can worsen the condition.

The right time to visit a veterinarian

In the case of a noticeable change in the eye, a veterinary check is generally recommended. This is especially true if the symptoms are pronounced or do not disappear quickly.

This is because there can also be more serious conditions behind a red eye. Glaucoma or inflammation inside the eye, for example, can also lead to redness, pain, and squinting, and must be treated quickly. Injuries to the cornea can also cause similar symptoms.

You should therefore be particularly vigilant if your dog is squinting its eye tightly or not opening it at all, shows obvious pain, has heavy or bloody discharge, or shows a cloudy, gray, or bluish change in the eye. Your dog should also be examined by a veterinarian quickly after an eye injury or in the case of sudden vision loss.

Prevention and eye care

Not every case of conjunctivitis can be prevented. Nevertheless, you can pay attention to a few things to expose your dog's eyes to as few unnecessary irritants as possible.

Dust, strong drafts, and foreign objects can irritate the sensitive eye area. After walks, you can carefully check your dog's eye area as needed and remove visible dirt with a clean, damp cloth.

For dogs with recurring eye problems, a veterinarian should also check whether, for example, an allergy, a dry eye, or an anatomical abnormality is the root cause.

Frequently asked questions about conjunctivitis in dogs

Can conjunctivitis in dogs heal on its own?

Mild inflammation caused by external irritants can sometimes resolve on its own. However, this does not apply to every form of conjunctivitis. Since other eye diseases can also cause similar symptoms, a persistently red or painful eye should be examined by a veterinarian.

What helps with conjunctivitis in dogs?

What actually helps depends on the cause. In the case of a bacterial infection, for example, special antibiotic eye drops or ointments may be necessary, while for an allergic cause, other treatment is required. Supporting measures include keeping the eye area carefully clean and preventing the dog from rubbing its eye.

Is a dog with conjunctivitis allowed to go outside?

With mild inflammation, short walks are generally possible. However, strong wind, dust, and pollen can place additional strain on the irritated eye. In cases of severe pain, pronounced light sensitivity, or a significantly worsened general condition, the cause should be clarified by a veterinarian first.

Is conjunctivitis transmissible from dogs to humans?

That depends on the cause of the conjunctivitis. Inflammation triggered by dust, allergies, or other non-infectious irritants is not transmissible from dog to human. With infectious causes, the transmission of pathogens can generally be possible, although this depends on the specific pathogen. In the case of an unclear or potentially infectious condition, good hygiene measures such as thorough hand washing after contact with the eyes are sensible.