Issue Description A cataract is a clouding that develops in the
crystalline lens of the eye or in its envelope, varying in degree from
slight to complete opacity and obstructing the passage of light.
Cataracts typically progress slowly to cause vision loss and are
potentially blinding if untreated.
Causes Cataracts can be hereditary or due to old age.
Inherited conditions are the most common cause of cataracts and may be
present at birth or develop when the animal is very young. They can
also be caused by injury, or illness such as diabetes. If your pet's
cataracts are due to an underlying condition, such as diabetes,
treating the condition may diminish the cataracts.
Symptoms Age of Onset The age at which a dog develops cataracts is
very important in classifying the type of cataract. The age of onset
is particularly important for determining if the cataracts are the
result of a hereditary trait in certain breeds of dogs.
Congenital Cataracts These are cataracts that are present at birth.
These cataracts usually occur in both eyes. Despite the fact that the
animal is born with them, they are not necessarily inherited.
Infections or toxins may cause the formation of these cataracts in
unborn puppies. Primary congenital cataracts such as those found in
Miniature Schnauzers are, however, inherited.
Developmental Cataracts Developmental cataracts are those that develop
early on in life. As with congenital cataracts, they may be inherited
or caused by outside sources such as trauma, diabetes mellitus,
infection, or toxicity. Inherited cataracts at this age are more
common in several breeds including Afghan Hounds and Standard Poodles.
Senile Cataracts The cataracts that occur in dogs over six years
of age are called senile cataracts. They occur much less frequently in
dogs than in humans. Nuclear sclerosis, which is not considered to be
a medical problem, is often confused with cataracts at this age.
Inherited Cataracts Inherited cataracts in the dog may occur
independently or in association with other ocular disease. Some of the
breeds that appear to develop inherited cataracts along with their age
of onset are listed below. If a dog is diagnosed with inherited
cataracts, the dog should obviously not be used for breeding because
of the likelihood of perpetuating the disease in the offspring.
Trauma Trauma from an automobile accident, or
penetration of a thorn, shotgun pellet, or other object may damage the
lens and a cataract may develop. These types of cataracts usually only
occur in one eye and can be treated successfully with surgical
Treatment There is no effective medical treatment for
cataracts. Cataracts are not painful, but when your pet has trouble
navigating due to vision loss, his sight can be restored to near
normal through surgery. A veterinary ophthalmologist will surgically
remove the lens, replacing it with a plastic or acrylic prosthetic
lens to allow for more focused vision. Cataract surgery generally has
a 90-95% success rate, but it is also a very delicate procedure that
requires extensive postoperative care by the pet owner.
After surgery, your pet will have to wear a protective collar
(Elizabethan Collar) until his eye heals and you will need to keep him
quiet and calm. Your pet will also require eye drops to be
administered several times a day for a few weeks.
your veterinarian can decide if cataracts are affecting your pet's
vision enough to warrant surgery.
Cataract surgery is a
highly successful procedure, but there are risks. Chances of the pet
having improved vision after surgery are high for most patients
(90%-95%). But 5% to 10% of dogs will not regain good vision due to
complications, and may actually be permanently blind in one or both of
the operated eyes.
Scar Tissue All dogs develop some intraocular scar tissue.
Excessive scar tissue will limit vision.
Glaucoma Glaucoma (increase in eye pressure) occurs in
30% of all dogs who have cataract surgery, usually within the first 24
hours after surgery. Most of these pressure increases are temporary
and quickly resolve with treatment. Glaucoma not only can cause
complete vision loss, but also may require the need for additional
medications or surgery. It can be painful and cause loss of the eye if
Retinal Detachment While re-attachment is sometimes possible, the
success rate is low and this complication usually results in complete
Intraocular Infection While it is rare, it can cause loss of the eye
(i.e. surgical removal of the eye) as well as complete vision loss.