Your cat just came on from outside, and he’s squinting his right eye. On closer inspection, the eye also looks a bit red and cloudy. A quick search online tells you it might be a corneal ulcer. Let’s look at this painful condition and what your vet will do.
What Is a Corneal Ulcer?
A corneal ulcer is also referred to as an erosion in the cornea. The cornea is a membrane that covers the surface of the eye. The cornea has three main layers: the epithelium, the stroma, and Descemet’s membrane. There are three main classifications of corneal ulcers:
- Superficial
- Deep
- Descemetocele
What Are the Signs of a Corneal Ulcer in Cats?
Corneal ulcers tend to be quite painful. Think of a time when you got an eyelash on your eye. It’s painful, so you might see signs associated with pain:
- Blepharospasm or squinting
- Pawing at the face or rubbing the face on the ground or furniture
- They might also blink quickly or keep their eye closed
The cornea may look cloudy because fluid accumulates in the stroma. You might also see an apparent defect in the cornea. The conjunctiva could become inflamed and red, so an increased tear drainage from the affected eye could appear.
What Are the Causes of a Corneal Ulcer in Cats?
Your cat can develop a corneal ulcer from a variety of causes. Trauma is the most likely cause. Cats might have traumatic injuries to the eye from:
- Scratches from a catfight
- Leaves or thorns when wandering outside
- Rubbing their face against the side of your chair or couch
Caustic injuries can also lead to corneal ulcers. Chemicals like shampoos that get into cats’ eyes can irritate the cornea. Certain viral infections, such as feline herpesvirus, can contribute to the formation of corneal ulcers, and even bacterial infections are possible causes.
Dry eye, or keratoconjunctivitis sicca, is associated with decreased tear production in your cat’s eyes. Without the protective tear film, your cat could develop keratitis or corneal ulcers, so teasing the dry eye is essential.
Diagnosing a Corneal Ulcer in Your Cat
Your veterinarian might be able to see a corneal ulcer with the naked eye if it is large or deep, but typically, your vet will need to perform a test called a fluorescein eye stain. A drop of a stain is placed on the eye. This stain adheres to the edge of an ulcer and glows bright yellowish green under a black light.
This test helps visualize the size of the defect on the corneal surface. It allows your veterinarian to track how the ulcer is healing.
A downside to this test is that if your veterinarian needs to measure your dog’s tear production or get a culture sample, those tests are typically done first. In fact, eye stain will invalidate a Schirmer tear test to measure tear production because you’re adding a liquid to the eye’s surface.
How Do I Care for a Cat With a Corneal Ulcer?
There are several ways that corneal ulcers are treated in pets, depending on how extensive the ulcer is.
Antibiotics
Your veterinarian will likely prescribe antibiotic drops or an ointment to be applied regularly to the eye to treat an infection if it is present or prevent an infection while the ulcer heals. Antibiotic drops such as tobramycin must be used every few hours because they don’t last long on the eye’s surface. (Blinking and normal tears will clear them.) Ointments will last longer but must be applied about every six hours.
Do not use antibiotics with a steroid added to the mix (unless your veterinarian has a specific reason for using these). The steroid drops can make your cat’s corneal ulcer worse.
Pain Relief
Pain relief is essential when dealing with an ulcer. Ophthalmic atropine is useful and long-acting.
In some circumstances, such as significant ocular inflammation or other trauma, your veterinarian may prescribe an oral anti-inflammatory medication. Examples include Onsior (robenacoxib) and Metacam (meloxicam).
Other Treatment
Your veterinarian might collect a small blood sample to create a serum for your cat’s eye. You’ll need to follow directions on how often to apply it and when in the regimen you’ll need to use it (before or after antibiotics, how frequently).
Surgery
Some corneal ulcers are so extensive that surgery is needed to repair the injury. Your veterinarian or ophthalmologist will likely need to perform a surgical repair with a descemetocele. As part of the procedure, the veterinarian will usually make a flap and suture some of the third eyelid over the defect.
A keratectomy is another procedure that might be needed, especially if your cat’s corneal ulcer isn’t healing normally. During this procedure, dead corneal tissue is gently debrided from the eye.
Other Notes on Treatment
Your cat should wear an e-collar while being treated for a corneal ulcer. This device will help prevent your cat from rubbing its eye. Your veterinarian will likely suggest regular recheck appointments until your cat’s corneal ulcer is resolved. These appointments are essential because a non-healing ulcer needs more intensive management and may require surgery.
Frequently Asked Questions (FAQ)
How long does it take for a corneal ulcer to heal in cats?
Simple or superficial corneal ulcers usually only take several days to heal, roughly three to five.
More complex ulcers may need surgical correction and could take several weeks to heal.
What antibiotics are used to treat corneal ulcers in cats?
Commonly used ophthalmic antibiotics in cats include:
- Bacitracin-Neomycin-Polymyxin
- Terramycin
- Tobramycin
Some cats are sensitive to certain antibiotics, so you’ll want to monitor them closely. Contact your veterinarian if your cat’s eye is worsening or not improving.
Conclusion
Corneal ulcers generally need a helping hand to heal. These ocular injuries can infect quickly, so ophthalmic antibiotics are often needed. Surgery may also be required, so take your cat to the vet at the first sign of squinting.
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Featured Image Credit: New Africa, Shutterstock