My dog, Misty, was diagnosed with cataracts. I hope to educate fellow dog guardians about common eye problems in dogs.
Dr. Mark, U of Missouri Veterinary Medicine grad with 40+ years working with dogs, exotics and livestock
Dog Eye Problems
Eye problems are common medical nuisances that occur in canines as much as in humans. They cause tremendous annoyance to the dog and the owner and can even cause blindness when not attended to. In certain cases, it may not occur to owners that their dogs have problems.
Always seek the advice of your veterinarian to keep your dog's eyes healthy.
The Experience of a Senior Dog
As often as they do in us, cataracts occur very often in senior pets aged six and over. I could not understand why my miniature schnauzer, Misty, kept bumping into things until I brought her to a vet, and a transparent film over her eyes was seen. She was diagnosed with a cataract and is pending removal as we wait to bring her for her next appointment. If left there, it could cause blindness. Later in this article, I will discuss the nature of cataracts, especially those caused by diabetes.
Dog Eye Diseases
Symptoms of Eye Problems in Dogs
Eye problems in dogs can be very obvious, but owners must be more conscious of them. We often just subscribe our dog’s actions to “doggy” behavior and do not take them very seriously. Their behavior is dismissed as just being “cute” and not an actual problem. How does a dog show us when its eyes are causing discomfort?
Pain in the Eyes
A dog tells us when it is suffering pain when it squints, tears, or shows sensitivity to light. Other symptoms will include sensitivity to touch as well. The nictitating membrane, or the third eyelid in dogs, protrudes when a dog’s eyes are experiencing any of the conditions that will be discussed later. This is a sign that a canine’s eyes are suffering severe pain.
Eye conditions in dogs are usually accompanied by discharge. The type of discharge will usually determine the kind of problem the dog has with its eyes. A painless discharge signals conjunctivitis. Any discharge accompanied by pain or whining should alert an owner to corneal or inner eye problems.
Film Over the Eye
An opaque film over the eyes signals problems with the third eyelid or nictitating membrane. When the nictitating membrane appears, the eyeball has sunken into its socket, or the eyeball has been pulled back into its socket because of severe pain.
When a dog experiences cloudiness over the eye, it is a sign of keratitis, glaucoma, or uveitis. A buildup of fluid in the cornea, known as corneal edema, will also give the eye an unclear appearance. Signs of pain usually accompany these.
When the dog does not show signs of pain, cataracts are probably the cause. The dog is not necessarily blind but probably has some difficulty seeing with clarity.
Changes in Eye Pressure
Changes in eye pressure mean that dogs may develop “hard” or “soft” eyes. These are a result of eye diseases in the inner eye. Hard eyes with an inner pupil would mean glaucoma. Soft eyes with small pupils indicate uveitis.
Irritation of the Eyelids
The irritation of the eyelids results from diseases that cause swelling, crusting, itching, or hair loss. These are conditions related to hormonal excess or deficiency. Skin problems in dogs will be discussed in another article.
Bulging or Sunken Eyes
These occur due to tumors, glaucoma, or even abscesses behind the eyeball, pushing the eye out of its socket. A sunken eye occurs with dehydration, weight loss, eye pain, and tetanus. Some breeds, such as Pugs, have eyes that normally bulge somewhat.
Eye Diseases That Are Common in Dogs
What are some of the eye conditions that are prevalent in dogs? Here are some that arise often, plaguing dogs and their owners.
- Cherry Eye
- Uveitis or the “Soft Eye”
1. Cherry Eye
What Is Cherry Eye?
A dog that has a Cherry Eye usually has a red lump at the corner of the eye. This happens when there is a prolapse of the nictitans gland, a gland beneath the third eyelid that helps lubricate the eye. Such prolapse causes the third eyelid to protrude or “fall out.”
The cause of this condition is not fully known but has been thought to be a weakness in the eye tissue that holds the membrane in place.
Genetics has also been thought to play a role, with breeds like Sharpeis, Bulldogs, Beagles, and Boston Terriers reportedly having a higher incidence of the condition.
The condition is not painful but can cause dry eyes because the glands cannot produce tears. Irritation because of exposure can result.
There are two options for treatment. The third eyelid can be either replaced or the tear gland removed. Vets used to remove glands many years ago, but with the importance of tear production, especially in the latter part of the dog’s life, most opt to replace the eyelid instead. The veterinarian will offer the best course of treatment.
What Is Conjunctivitis?
Conjunctivitis, or “pink eye,” as it is less technically known, is the inflammation of the pink membrane that covers the front of the eyeball and inside of the eyelids. It can be acute, chronic, infectious or noninfectious.
Conjunctivitis is divided into two types, serous and purulent. Serious conjunctivitis is a mild condition in which the conjunctiva looks pink and swollen. The discharge is clear and watery. Common causes include wind, dust and allergens. Serious conjunctivitis becomes purulent when thick secretions crust the lids, and the discharge contains mucus or pus.
The third eye, as mentioned above, will usually protrude when there is conjunctivitis. The dog will usually experience blinking, squinting and be pawing at his eye.
Conjunctivitis may be caused by:
- Bacterial infection
- Anatomical Abnormality
Treatment differs based on the severity of the case. Mild cases of conjunctivitis merely require the flushing of the eye with saline or topical ointments with mild steroids. Purulent or more serious conjunctivitis may require eye irrigations. Antibiotics may be given to combat eye infections. Anti-inflammatories may be given to combat inflammation.
Note: Do not give anti-inflammatories to dogs with infections, as this can cause the infection to get even worse!
What Is Glaucoma?
A serious eye condition, glaucoma leads to blindness when not treated. It arises because the fluid in the eye is produced faster than it can be removed. It leads to intraocular pressure or pressure within the eye. When the pressure is too high, it causes degenerative changes to the optic nerve.
Glaucoma can be acute or chronic, depending on how quickly the signs develop. An eye with acute glaucoma develops suddenly and is very painful, causing the dog to squint and tear. The affected eye is harder than the other, causing the dog to have a fixed blank look. Glaucoma causes your dog to have chronic migraine.
Chronic glaucoma develops over time. It is chronic when the eyeball slowly begins to protrude due to the developing mass behind it.
Glaucoma can be primary (hereditary) or secondary (resulting from another disease).
Hereditary glaucoma affects breeds like Basset Hounds, Samoyeds, Beagles, and Cocker Spaniels. In 50% of cases, one eye is soon affected after the first.
Secondary glaucoma can arise from other eye diseases like cataracts, uveitis, and tumors.
Acute glaucoma is an emergency that needs to be treated immediately, or it can cause blindness. The dog needs to be rushed to the veterinary hospital. Doctors usually administer the drug mannitol intravenously through a drip or use inhibitors that block the enzyme that produces the fluid building up behind the eye. Some may give the inhibiting drugs orally together with drugs like Xalatan.
What Are Cataracts?
A cataract occurs when the dog’s eyes turn opaque and cause him to have blurred vision. Cataracts should be removed as early as possible to prevent them from the possible complication of glaucoma and eventual blindness. Dogs of all ages and breeds can develop cataracts, but they are more commonly found in cocker spaniels, poodles, miniature schnauzers, terriers, and golden retrievers.
Cataracts can result from old age, trauma or secondary complications from diseases like glaucoma. Most often, they result because of an inherited condition. They can, therefore, be present at birth or develop when a dog is very young.
Cataracts can also result as a secondary complication of diseases such as diabetes. A small consolation is that dogs with cataracts have higher surgical success rates.
A visit to a veterinarian is essential once a pet owner notices that its eyes are turning blush grey. The vet will recommend the additional steps for treatment or surgery.
5. Uveitis or the “Soft Eye”
Uveitis is a condition when a dog's uvea becomes inflamed. The "uvea" is a portion of the dog eye comprised of the iris, ciliary body, and choroid. Uveitis can lead to dramatic decrease in eye pressure, resulting in something called “soft eye.”
It is painful and accompanied by a red eye, severe tearing and squinting, the third eyelid protruding and avoidance of light. The pupil reacts slowly to light because it is too small.
If left untreated, the dog suffers from a sunken eye and eventual blindness.
Uveitis comes about when the iris becomes inflamed. The iris works like the shutter on a camera, blocking the pupil from excess light. When it becomes inflamed, there is a drastic decrease of pressure within the eye because of a reduction in the fluid that maintains this pressure. This fluid is produced by the structure of the eye known as the ciliary body.