Red Eyes in Cats

Key takeaways

Red eyes occur in cats when there is a change of color in the white part of the eyeball. Typically, redness indicates that an underlying condition has stimulated the blood vessels to bring more blood to the eye.

  • Red eyes are a common symptom, and one that is associated with a wide range of conditions
  • The most common underlying conditions for red eyes in cats are conjunctivitis, uveitis, and glaucoma
  • Some of the causes for red eyes are mild and do not affect overall health or eyesight, but others are serious and life-threatening
  • Immediate veterinary care is required in cases where red eyes are accompanied by signs of severe pain or vision loss
  • Diagnostic tools include physical examination, ophthalmological examination, blood work, urinalysis, infectious disease testing, and diagnostic imaging
  • Treatment is highly variable depending on the underlying cause
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A closer look: Red Eyes in Cats

Red eyes are a very common symptom in cats. It is a highly variable symptom and warrants veterinary attention to diagnose the underlying cause and plan treatment.

In many cases, the conditions associated with red eyes are mild, and resolve with minimal treatment. In some cases, red eyes indicate serious health conditions that require emergency veterinary care in order to prevent permanent loss of eyesight. In very serious cases, red eyes indicate life threatening conditions.

**Immediate veterinary care is warranted in cases where red eyes are accompanied by emergency symptoms.

Emergency veterinary care is required if red eyes are accompanied by:

  • Signs of pain including hiding, avoiding interaction or play, changes in behavior including aggression, and excessive sleeping
  • Sudden vision loss (seen as bumping into objects and unwillingness to move)

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Possible causes

There are many conditions associated with red eyes. In some cases, the redness is caused by dysfunction or injury to the eyeball or surrounding structures, including.

In other cases, systemic or infectious disease is the underlying cause.

Risk factors

Red eyes vary in severity based on a number of factors.

In some cases, such as with an injury or most tumors, the redness develops in one eye. In other cases, such as with systemic illnesses, poisoning, or viruses, both eyes are affected.

While some cases may present with red eyes as the only ocular symptom, other cases may be accompanied by squinting, tearing, or signs of pain.

The onset of red eyes may be sudden such as with poisoning, whereas in other cases the eyes may get progressively redder over time as with uveitis or conjunctivitis.

In some cases, redness of the eyes does not return following treatment, such as with an injury or certain infections. Sometimes the redness comes and goes regularly, such as seasonal allergic responses to pollen. In other cases, redness occurs repetitively and does not resolve without surgical treatment, such as with eyelash or eyelid disorders.

Testing and diagnosis

Due to the wide range of possible underlying conditions that leads to red eyes, veterinary care is beneficial to diagnose the specific cause and determine a treatment plan.

Diagnostic tools are chosen based on the specific symptoms that are present in each case. These may include:

  • Physical examination
  • Ophthalmological examination
  • Bloodwork
  • Infectious disease testing
  • Diagnostic imaging (X-ray, ultrasound, CT, MRI)
  • Urinalysis
  • Cytology (the examination of cells under the microscope)
  • Biopsy

Treatment varies widely, and depends on the diagnosis. These include:

  • Benign neglect
  • Elimination of allergens
  • Topical medications such as medicated eye drops or ointments
  • Oral medications including antibiotics, antivirals, and steroids
  • Pain medications
  • Surgery
  • Hospice care

Note: it is not safe to administer topical medications or eye drops to cats without veterinary guidance. Many human medications and over the counter remedies are toxic to cats.

Similar symptoms

Red eyes can be mistaken for redness and swelling of the skin around the eyes or of the eyelids. It is also possible to mistake masses in or around the eyes for redness of the eyeball itself.

Associated symptoms

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