Bulging Eyes in Cats

What Is Bulging Eyes in Cats?

The orbit is the eye socket where the eyeball, or globe, and associated tissues (glands, nerves, vessels, and those muscles responsible for eye movement) are housed.

The orbit is considered a fixed space. That means anything that would increase its volume or affect the eyeball would cause displacement—often causing the globe to be pushed forward, resulting in a “bulging” eye. This can often be described as one of the following:

• Buphthalmos—the globe is in a normal position but is enlarged; this is often attributed to glaucoma. One or both eyes can be affected. 

• Exophthalmos­—the globe itself is normal-sized but protrudes forward. Usually only one eye is affected.

• Proptosis—sudden, often traumatic, displacement of the globe, which is displaced outward from the eye socket. As a result, the eyelid gets trapped or stuck behind the globe.

Orbital disease is the umbrella term for anything that would affect this area. Cats have more bone surrounding their orbit, so the disease is less common than in dogs and often requires some form of surgical treatment.

If bulging eyes are noted, have your cat examined immediately by a veterinarian. This is considered an emergency, and since there are multiple causes of eye protrusion, treatment would vary based on diagnosis. 

Symptoms of Bulging Eyes in Cats

The main symptom of cats with bulging eyes is that the eye itself bulges or protrudes outward from the globe.  Cats can also exhibit other symptoms associated with this condition or as a result, including:

• Third eyelid protrusion
• Blindness
• Dull appearance to the cornea, often associated with dry eye
• Conjunctiva (white of the eye)
• Chemosis, or swelling, of the conjunctiva
• Difficulty closing the eyelids
• Periorbital swelling (i.e., swelling of the associated tissues)
• Discharge from the eye or surrounding skin might be commonly mistaken for a draining wound
• Sneezing and/or drainage from the nose
• Absent ocular reflexes
• Asymmetry to the face and sinuses
• Pain upon opening the mouth, often associated with inflamed gums and tissues in the back of the mouth
• Local lymph node enlargement
• Neurologic deficits
• Fever
• Decreased or absent appetite
• Lethargy, lack of energy

Severe symptoms may include:

• Hyphema, commonly seen as a “red eye” where the eye is filled with blood
• Pain especially when touched
• Normal to dilated pupil
• Surrounding abrasions and/or fractures with or without hemorrhage
• Other signs associated with head trauma such as coma, seizures
• Epistaxis (nosebleed)

Causes of Bulging Eyes in Cats

Bulging eyes in cats can be due to various underlying conditions including: 

• Abscess formation, caused by bacterial infection, fungal infection, or foreign bodies

• Inflammation or autoimmune disease

• Vehicular trauma or trauma experienced from falling, fighting, dog attacks, or abuse (it’s important to note that given a cat’s anatomy, severe trauma is often required to cause proptosis)

• Disease

• Dental disease; tooth root abscess

• Cancer

• Swelling of salivary glands

Bulging eyes can occur in any cats of any breeds, however, younger, unneutered male cats may have a higher incidence of trauma-related proptosis due to territorial and mating behavior.

How Veterinarians Diagnose Bulging Eyes in Cats

After a complete physical exam, your veterinarian may perform a more in-depth ophthalmic exam followed by orbital palpation to determine if the globe is able to be pushed back in. Ocular tests may be performed, such as a Schirmer Tear Test to measure tear production, a fluorescein eye stain to look for corneal ulcerations and abrasions, or an intraocular pressure (IOP) test to measure pressure within the eye. 

Symptoms can mimic other diseases, so your veterinarian may recommend basic blood work like a complete blood cell count (CBC), internal organ function screening, blood pressure, FeLV/FIV/HWT testing, thyroid evaluation, and urinalysis.  The results from these tests provide a baseline and can also aid surgical and anesthetic planning and rule out other conditions.

Additionally, your veterinarian may examine the oral cavity looking for any signs of dental disease, such as infected teeth, swelling of the gums or tissues, or discharge.

Your vet may refer you to a veterinary ophthalmologist for specialized procedures such as an ocular ultrasound or CT and MRI to look at structures behind the eye, assist with surgical planning, and to aid in diagnosis. X-rays of the chest coupled with X-rays or ultrasound of the abdomen may be done to look for evidence of tumor spread (metastasis).

Treatment of Bulging Eyes in Cats

Treatment for bulging eyes in cats may be surgical (proptosis, cancer, dental disease, trauma, foreign body) or medical (infectious, inflammatory) depending on the diagnosis. 

For any displaced eye, the sooner it can be put back in the place the better. However, given a cat’s orbital bony structure, if proptosis is the underlying cause, it usually carries a less favorable outcome due to the severity of trauma encountered, and enucleation is often performed. Enucleation is the surgical removal of the eyeball and its associated tissues. Enucleation is often performed in cases where:

• The eye has ruptured

• Three or more eye muscles are ruptured or torn

• The eye has filled with blood

• A tumor is diagnosed

• The pet parent is unable or cannot commit to potential long-term care

In some cases, the eye can be salvaged but the prognosis for vision is poor. In these cases, once the cat is stabilized, they are anesthetized and surgical replacement of the globe back into the orbit is performed. A temporary tarsorrhaphy (surgical closure of the eyelids) is performed, and frequent ocular (and oral) medications are then administered to aid swelling, inflammation, pain, and infection. 

Consultation and treatment of cancer with a veterinary oncologist for chemotherapy and radiation therapeutic recommendations may be necessary, depending on the diagnosis.   

Recovery and Management of Bulging Eyes in Cats

After surgery, your cat should be kept in a calm and stress-free environment with time given for a chance to acclimate, especially for those cats who underwent an enucleation. 

Partially blind cats can still have a good quality of life with little inconvenience to their pet parents.  Sutures will most likely be present, which will need to be removed in a few weeks. It’s also normal for there to be some swelling and bruising, which should dissipate after a few days. Your cat will be sent home with medications and an e-collar or recovery cone to prevent their scratching or rubbing at the incision.  

Follow your veterinarian's advice and reach out if there are any concerns or further symptoms noted. Sometimes there is residual bleeding or draining from the surgical site, which will need to be addressed. Your veterinarian may recommend compresses to help with the swelling, along with recommendations for exercise restriction or cage rest.

For cats that underwent a tarsorrhaphy or other procedure, recovery will be dependent on their case. Weekly follow-up visits will ensure proper tension of the temporary sutures, along with monitoring for any signs of recurrence of vision. A complete recovery may take several months and some conditions can take longer to see improvement. Medications will vary and may be given frequently during recovery. Your cat may require a special diet or at least need soft food for the first few weeks without any access to chew toys, especially if they underwent a dental procedure. 

Long-term complications can occur, such as dry eye or corneal ulceration. Follow-up appointments and tests may also be required.

Prevention of Bulging Eyes in Cats

Early diagnosis and treatment are key and often minimize pain and discomfort and provide a better prognosis. Monitor your cat closely for any changes to the eyes, and if so, have them examined right away.  Keeping your cat indoors, away from high-energy dogs and cats, and providing it with routine medical and dental care can lessen the chances of developing eye protrusion.