What is conjunctivitis in dogs?

Conjunctivitis is a common condition where the conjunctiva (the thin membrane covering the whites of the eyes and lining the insides of the eyelids) becomes inflamed. It can be infectious or non-infectious and is usually fairly easy to treat, although occasionally it can be caused by a more serious health condition.

What causes conjunctivitis in dogs?

Conjunctivitis can be classified according to whether or not it is infectious:

• Infectious conjunctivitis
  • This is caused by a viral or bacterial infection and is potentially contagious. It may start in one eye but then spread to the other.
  • Underlying problems such as dry eye can predispose to infectious conjunctivitis.

• Non-infectious conjunctivitis – possible causes include:
  • Allergies
  • A foreign body in the eye e.g. a grass seed
  • Dry eye (reduced tear production makes the eyes inflamed and sore)
  • Corneal ulcer – these can cause the conjunctiva to become inflamed
  • Eyelash problems - sometimes eyelashes grow in the wrong place or at the wrong angle – these can sometimes irritate the conjunctiva, causing it to become inflamed.
  • Eye diseases including glaucoma

What are the symptoms of conjunctivitis in dogs?

The symptoms can include:

• Red eye
• Discharge from the eye
• Dog rubbing at the eye
• Closing the eye or blinking more than usual

If you have any concerns about your dog’s eyes, then please contact your vet.

How is conjunctivitis in dogs diagnosed?

The vet will normally be able to diagnose conjunctivitis based on an examination of your dog’s eyes. They will want to rule out other problems such as corneal ulceration and dry eye. Ulcers can be checked for using a special dye in the eye, while dry eye is ruled out by measuring the tear production using special paper strips placed under your dog’s lower eyelid. They will also check the eye(s) thoroughly to check for a foreign body or an eyelash growing in the wrong place.

How is conjunctivitis in dogs treated?

The treatment will depend on the underlying cause. For instance, if there is a foreign body within the eye this will need to be removed. Most cases, however, respond well to medication eye drops or ointment, although recurrent conjunctivitis would warrant further investigation.  Your dog may need a buster collar while they are recovering to prevent self-trauma.