Diagnosing a Cat Eye Discharge

Cat eye discharge is not a disease but a symptom of eye infection or eye disorder. Healthy eyes should be bright and free from discharge or redness. In order to treat pets suffering from eye discharge, it's necessary to understand various eye conditions or bodily ailments that cause discharge. Eye discharge that's visible after the cat wakes from sleep is a common feature. However prolonged eye discharge or discharge that's accompanied by inflammation requires medical intervention.

Common Causes of Cat Eye Discharge

  • Abnormal eye formation
  • Conjunctivitis
  • Corneal ulcers
  • Glaucoma
  • Trauma

Diagnosis of Cat Eye Discharge

In order to diagnose eye discharge, the vet will perform an ophthalmic examination to detect any changes in the cornea or internal chambers of the eye. A known test to determine tear production is known as the Schirmer tear test. During this test the vet will place a Schirmer test strip on the lower lid of the eye to stimulate tear production. Tears will be collected on the strip and measured against a standard. Another diagnostic test that confirms abrasions, ulcers or corneal damage is a fluorescein stain test. To perform this test, the vet will insert a few drops of orange stain and allow the eye to rest for a few minutes. The stain is then washed off in order to examine the eye. The stain outlines or adheres to corneal ulcers and abrasions after washing the eye, thus detecting abnormalities. In addition to fluorescein testing, the vet may perform a corneal scraping test to analyze the sample of cells under a microscope.

Other Tests

Pets suspected of upper respiratory illnesses will be tested with specific blood tests and fecal exams to rule out the condition. CT scans and other X-rays will also confirm diagnosis. The vet will evaluate the cat's medical history and consider the risk of eye disease due to genetic factors. Since eye discharge is caused by certain common conditions, it's important to understand these diseases in order to diagnose and treat pets promptly.

Abnormal Eye Formation

Pets that are born with eye deformities or inverted eyelids often suffer from eye discharge. An inverted eyelid can cause internal eye irritation and cause increased tear production or eye infection. Eye discharge that's thick or tinted in color is an indication of eye infection.


Conjunctivitis is also known as cat pink eye. It's an inflammation of the conjunctiva due to chemical irritants or allergens present in the environment. In addition, fungal infections or viral diseases cause conjunctivitis. Most pets suspected of conjunctivitis are tested for feline immunodeficiency virus.

Corneal Ulcers

Corneal ulcers occur when the cells in the cornea are damaged or lost. Ulcers develop due to several eye conditions such as keratoconjunctivitis, trauma or presence of foreign bodies. Pets suffering from corneal ulcers have mucus like eye drainage from the eye.


Cats suffering from glaucoma have high eye pressure. The pet's eye pressure is determined with a tool known as a tonometer. Glaucoma develops due to a decrease in drainage of aqueous humor in the eye. The condition often accompanies other eye disorders and pets require prompt diagnosis from a veterinary ophthalmologist to expedite treatment.


Eye discharge may also occur due to accidental eye damage or the presence of foreign bodies or objects in the eye.

In order to treat cats for eye discharge, the vet will have to determine its underlying cause. Any symptoms of eye disease should be diagnosed and treated promptly to prevent eye damage.