Keep eye on our pet’s eyes
By Dr. Daniel Eubanks, Special Writer
Comparative anatomy tells us we humans are unmistakably similar to our evolutionary predecessors.
Some anatomical likenesses are obscure and require some imagination. For instance, our fingernail and a horse’s hoof are actually dramatic variants of the same tissue.
The canine and feline eye, however, remain remarkably similar to our own. Even the slit-like pupil of the cat’s eye is merely a functional modification, not an anatomical one.
Like the anatomy, the disorders of dog’s and cat’s eyes are very much the same as our own.
The vast majority of our pet’s ocular problems involve the exterior tissues of the eye — the conjunctiva and the cornea.
The conjunctiva is a thin mucous producing membrane that covers the underside of the eyelids and reflects back onto the white sclera of the eyeball. It provides protection and lubrication for the eye.
The most common disorder of the conjunctiva is inflammation or conjunctivitis — similar to “pink-eye” in people. In dogs, conjunctivitis is almost never contagious, frequently not even affecting both eyes of the same patient.
Feline viral respiratory infections can have an ocular component, and this conjunctivitis would be considered contagious to other cats.
Most conjunctivitis is caused by environmental irritants — dust, molds, pollen, wind, etc. Allergy is often involved, but not necessarily. Remember, our pet’s eyes are much closer to the ground and subject to a lot more airborne debris.
Bacterial infection is usually secondary to the inflammation and, therefore, not considered to be contagious.
As the pet’s owner and best friend, you should be aware of signs of ocular disease as the pet cannot verbally communicate. Signs of conjunctivitis are exactly the same as with our own eyes — redness, discharge and sometimes pain.
Eye pain in pets is heralded by squinting and sometimes rubbing the eyes with their paws on upholstery or carpet.
The cornea is the transparent cover in the center of the eye directly overlying the iris — the pretty blue or brown inner structure. The cornea is avasuclar (no blood vessels) but highly innervated. Corneal lesions are serious as they can lead to perforation or permanent scarring, resulting in loss of vision.
Most of our pet’s corneal problems are due to injury. Abrasions, lacerations or puncture due to foreign body or fighting are common. Chemical irritants such as soaps and insecticidal dips can cause inflammation of the cornea or keratitis.
Chronic irritation from various structural abnormalities of the eyelids can wreak havoc on the cornea.
The consistent sign of these corneal abnormalities is intense pain. Often, opacity can be seen as a cloudy or whitish lesion on the otherwise totally clear, transparent cornea.
KCS is an ocular disease seen in our pets as well as humans. The acronym stands for keratoconjunctivitis sicca, literally translated as inflammation of both cornea and conjunctiva caused by dryness. If the lacrimal (tear) glands cease to produce tears, the tissues dry out and become inflamed.
Signs are still the same — ocular discharge and chronic pain. The cornea can ultimately become inflamed. The cornea can ultimately become opaque with pigmented scar tissue and subsequent blindness.
Diseases of the interior structures of the eye are either encountered less frequently or not often addressed. Glaucoma and cataract are relatively common. Intraocular lesions such as retinal degeneration, etc., are less frequently diagnosed and even less often addressed.
Veterinary ophthalmology specialists (board certified, advanced degree) are readily available these days, and they tend to most of the complicated internal disorders, including surgery for glaucoma and cataracts.
Eyeballs can be spooky things, especially at Halloween. Most folks shy away and prefer not to even look at them too closely.
The purpose of this article is to alert you to the signs of ocular illness in pets — redness, discharge and pain exhibited by squinting or rubbing. These are dependable indicators of a problem that should be examined.
Eye problems are usually prioritized at most veterinary clinics.

