Conjunctivitis in Dogs

Overview:

Conjunctivitis is common disease in dogs. It is defined as inflammation of the conjunctiva, which is the pink membrane which covers the front of the eyeball & the inside of the eyelids. Conjunctivitis can affect one eye (unilateral) or both eyes (bilateral) & covers a broad range of possible conditions which cause conjunctival inflammation which can be acute or chronic, infectious or non-infectious.

It is extremely important to seek veterinary care when it comes to eye conditions. Failure to do so could result in loss of vision.

Causes of conjunctivitis:

Viral & bacterial infections are the most common cause of conjunctivitis in dogs. Conjunctivitis may occur as a secondary result of another disease. Below are some possible causes;

• Viral infections such as canine distemper.

• Bacterial infections such as Staphylococci spp. and Streptococci spp.

• Keratoconjunctivitis sicca (KCS/dry eye) - This is an inflammation of both the cornea & the conjunctiva & sicca means dry. This is caused by a lack of tears reaching the surface of the eyes which is caused by trauma, inflammation of the conjunctival glands & ducts, scarring etc.

• Allergies (plants, pollens etc)

• Foreign object (grass seed, hair, eyelash)

• Irritants (eg; smoke, fumes, dust)

• Injury (scratch)

• Anatomical abnormalities such as

• Parasites.

• Fungal infections.

• Tumours.

• Idiopathic (no known cause).

What are the symptoms of conjunctivitis?

• Ocular discharge. This will vary depending on the cause of the conjunctivitis. It may either be clear & watery or thick, containing mucus or pus.

• The conjunctiva becomes red & swollen, often with a meaty appearance.

• Blinking.

• Squinting.

• Pawing & rubbing at the eye.

• Third eye protrusion.

• The dog may also show signs of upper respiratory infection such as sneezing, nasal discharge.

How is conjunctivitis diagnosed?

Your veterinarian will perform a physical examination including looking closely at the eyes & type of  discharge (watery, thick etc.) & obtain a history from you. He may be able to diagnose the cause based on signs & symptoms.

He may wish to perform some tests including;

• Conjunctival swab - Your veterinarian may take an eye swab from an infected dog which will be sent to a laboratory for testing. There are several tests which can be performed, including PCR (polymerase chain reaction), Immunofluorescent assay (IFA) or bacterial culture. 

• Fluorescein staining - This is a die which is used to stain & demonstrate ulcerations of the cornea.

How is canine conjunctivitis treated?

Treatment depends on the cause of conjunctivitis.

• Mild cases of conjunctivitis may only require flushing of the eye with a saline solution.

• Purulent conjunctivitis requires eye irrigations & warm soaks to loosen crusted eyelids.

• Antibiotics or eye ointment applied several times a day to treat bacterial infections.

• Antiviral eye medications for viral conjunctivitis.    

• L-Lysine has been shown to suppress viral replication and inhibit cytopathogenicity.

• If allergy is the cause, anti-inflammatories may be prescribed.

• If a foreign object is the cause, removal should solve the problem.

• Anti-fungal medications for fungal diseases.

Please note:

The medical articles on this site have not been written by a veterinarian & should not be considered a replacement for a veterinarian visit. The articles are provided for informative purposes only & should not be used for  the diagnosis or treatment of any medical condition. 

Always seek immediate veterinary advice for any problems (health or behavioral) in your pets. 

While great care has been made in the creation of these articles, we cannot guarantee the accuracy or omissions on these pages. If in any doubt whatsoever, seek professional medical advice.