Enucleation of the Eye in Cats and Dogs: What Is It, and How Can You Prepare Your Pet?

What Is Enucleation of the Eye in Cats and Dogs?

A cat or dog who has a painful and non-visual (blind) eye that isn’t responding to medical treatments may benefit from having the eye removed to promote comfort. The procedure for removing an eyeball is called an enucleation.

During an enucleation, the patient is under general anesthesia so that they don’t feel anything. Some veterinarians may also put medication such as lidocaine or bupivacaine behind the eye to further numb the area.

The area around the eye is shaved, and then the eye is surgically removed. The eyelids, the third eyelid, and any tear-producing structures are also removed.

The skin around the eye is sutured shut so the animal looks like it’s always winking (blinking if it’s both eyes).

Enucleation is a common procedure in both dogs and cats, and most general practitioners can perform the surgery.

Types of Enucleations of the Eye in Cats and Dogs

Veterinarians do enucleation of the eye in cats and dogs in two ways:

• A transconjunctival enucleation involves making an incision in the pinkish-white tissue directly around the globe (eyeball) and then methodically cutting around the back of the eye to remove the eyeball.

  • This approach decreases the amount of tissue that is lost, so there is usually less sinking of the tissue into the orbit (eye socket) after healing occurs. There's also usually less bleeding with this approach.

• A transpalpebral enucleation involves cutting directly through the eyelids and around the eyeball. More tissue is removed, so this approach is preferred for suspected eye infections or cancers.

If the eye and all soft tissue such as muscles are removed, this is called exenteration, not enucleation. Exenteration may be recommended if there is a large tumor in the eye socket.

Anatomy of the Eye in Cats and Dogs

The globe (eyeball) is held into the orbit (eye socket), by various muscles, which attach toward the back of the eye.

The optic nerve, which attaches to the back of the eye and travels through a hole in the skull to the brain, carries signals to the brain to produce vision.

Blood vessels travel with the optic nerve to supply blood to the eye.

The eye is attached to the eyelids by the conjunctiva, a thin membrane made of mucous tissue.

Dogs and cats also have a third eyelid at the inner corner of their eye, which plays an important role in tear production.

During most enucleation procedures, the globe and all tear-producing structures are removed.

All muscles, the optic nerve, and vessels to the eye are severed during the procedure. The stumps of the muscles and a stump of the optic nerve are left behind.

Why Would a Cat or Dog Need Enucleation of the Eye?

Generally, enucleation is recommended for pets with a painful, non-visual eye or for pets with cancer in their eye. Other reasons a cat or dog would need enucleation of an eye include:

• Glaucoma that is unresponsive to treatment

• Trauma to the eye that has led to perforation of the eye or serious damage

• Infection within the eye that’s not responding to medications

• An eyeball that has shriveled following a destructive disease (such as a condition called phthisis bulbi) and is chronically inflamed

• The eyeball has come out of its socket (a condition called proptosis), and there is significant damage to the globe, the muscles, or the optic nerve

Benefits of Enucleation of the Eye in Cats and Dogs

The primary benefit of this procedure is that it removes a source of pain.

In many cases, the eye is already non-visual, so no additional vision loss occurs.

In cases where the eye is still visual, you and your veterinarian have to weigh the benefits of vision against the ongoing pain your pet is experiencing.

If there are medications that can decrease your dog’s pain or slow the progression of eye disease, consider these before moving on to removing the eye.

For some conditions, advanced surgeries performed by an ophthalmologist are better options than removing the eye.

For example, early surgical management of cataracts can lead to lifelong ocular comfort and preserve vision, while untreated cataracts can eventually lead to glaucoma and the need to remove the eye.

Effectiveness of Enucleation of the Eye in Cats and Dogs

Keeping in mind that enucleation is meant to reduce pain, enucleation of the eye in cats and dogs is highly effective.

With proper post-operative management, most dogs do very well after surgery, even if both eyes have been removed. About 90% of pet parents of dogs who’ve had both eyes removed are satisfied with the results and feel their dog is in less pain and has a better life after the surgery.

Cost of Enucleation of the Eye in Cats and Dogs

The cost of an enucleation surgery varies depending on:

• Your geographic location

• Whether one or both eyes are being removed

• The type of clinic where your pet is getting the procedure done

• The diagnostic tests performed beforehand

• Your pet’s size

• The surgical approach used

Surgery can range from $475 to $2,000. For routine enucleations in a private practice, the cost is usually on the lower end of the range.

Preparation for Enucleation of the Eye in Cats and Dogs

When preparing for the surgery, your focus should be on preparing your home for your pet’s recovery.

Your veterinarian will usually instruct you to fast your pet overnight before the procedure to reduce the risk of vomiting and aspirating (inhaling the vomit) during anesthesia.

Most veterinarians allow pets to drink water up until the time of surgery, but it’s important to confirm this with your veterinarian.

At the hospital, your pet will likely have a catheter placed in their vein to administer fluids and medications directly into their bloodstream.

They will be sedated, and the area around their eye will be shaved and cleaned. An endotracheal tube will be inserted into their windpipe to assist with breathing, if needed.

In case your pet becomes anxious at the hospital, talk to your veterinarian before the appointment about using an anti-anxiety medication such as trazodone or gabapentin.

Complications of Enucleation of the Eye in Cats and Dogs

Common complications of enucleation in cats and dogs include:

• Surgical site infection

• The incision breaking open (dehiscence)

• Bleeding from the surgical site

• Pain associated with the surgical site

If for some reason the surgeon doesn’t remove all secretory tissues, the pet may develop cysts or drainage. This is uncommon and can typically be corrected with a second procedure.

The nerves going to the eyes are connected to one another, so the surgeon must use a gentle technique when removing one eye to avoid causing injury to and potential blindness in the other eye.

The risk of damaging the other eye during an enucleation is quite low.

As with any procedure involving anesthesia, there is a risk of rare adverse events due to the nature of surgery.

These can include reactions to anesthetic medications, seizures, aspiration pneumonia, cardiac arrest, or death.

Anesthetic-related death occurs in just one in 1,000 cats and one in 2,000 dogs undergoing general anesthesia in primary care clinics.

Post-Op Care and Recovery for Enucleation of the Eye in Cats and Dogs

If your pet was blind before the procedure, they’re likely already used to navigating your home while blind.

However, if your pet is newly blind, expect them to have an adjustment period of at least a few days.

The surgical site itself should heal within 10 to 14 days.

Your veterinarian may use sutures that dissolve under the skin, or they may have you come in after the incision has healed to remove external skin sutures.

Avoid getting the surgical site wet during this healing period.

You will need to keep a recovery cone on your pet during recovery to prevent them from causing injury to the surgical site.

Note that doughnut-type recovery cones are often insufficient for this procedure because your pet can rub their face on furniture and other objects.

Your pet will likely be on pain medications for the first few days after surgery. For dogs, you can expect an NSAID like carprofen.

Cats may be prescribed pain medications such as robenacoxib and buprenorphine. Your veterinarian will determine the appropriate pain management plan.

You can help your pet navigate your home by:

• Not moving furniture around

• Keeping food and water bowls in predictable locations

• Putting bells on other animals in the home so your pet can hear them approach

• Speaking to your pet before approaching or touching them

• Covering sharp edges, removing obstacles from the ground, and blocking off stairs

• Never leaving your pet outside unattended

• Taking your pet on the same familiar path for leashed walks (especially for dogs)

Alternatives to Enucleation of the Eye in Cats and Dogs

Enucleation of the eye in cats and dogs is typically recommended after medical treatments have been unsuccessful.

It’s considered after other medical and surgical treatments have not provided sufficient relief or are not feasible due to financial constraints.

While not a true alternative, some veterinarians may offer a prosthetic globe to replace the eye for pet parents who are concerned about their pet’s appearance after surgery.

It’s not common for veterinarians to substitute the removed eye with a false eye, but some veterinarians may perform an ocular implant.