Canine Cataracts

One of the most common problems affecting thedeveloping cataracts is very crucial in identifying
eyes of dogs is canine cataract. While caninethe type of cataract. The age of onset may help
cataract presents at different ages, and in variousto determine if the cataracts are hereditary or
forms, in general they can affect all dog breeds.trauma induced.
Recent research carried out by veterinaryCONGENITAL CATARACTS
scientists has shown that certain types of canineCongenital dog cataracts present at birth.
cataracts are more common in specific breeds.Congenital cataracts usually occur in both of the
Dog cataracts are very widespread, anddogs eyes. Although one might think that
unfortunately there is still a lot that we do notcongenital cataracts are inherited this is not
know about this condition.necessarily the case as puppies may be
This article covers some of the different formssusceptible to infections and/or toxins while still in
of dog cataracts and gives details of the likelythe womb.
age of onset.DEVELOPMENTAL (EARLY ONSET) CATARACTS
The word “cataract” actually means 'toDevelopmental cataracts start early in a pup’s
break down.' The breakdown referred to is thelife and may either be inherited or caused by
disruption of the natural arrangement of the lenssomething in the dogs environment. Inherited
fibers within the eye itself. This disruption resultscataracts at an early age are more common in
in a form of oxidation and a loss of transparencybreeds such as Standard Poodles, Afghan Hounds
to the lens. To the pet’s owner a dog’sand certain terrier breeds.
cataract often appears to have a milky whiteSENILE (LATE ONSET) CATARACTS
appearance. There is however a condition knownCataracts that occur in dogs over the age of 6
as nuclear sclerosis which has a similar appearanceyears are referred to as senile cataracts. Nuclear
to that of cataract. In many situations the milkysclerosis can often be confused with senile
eye of the dog is not due to canine cataracts, butcataracts.
to a condition that is known as 'nuclear sclerosis.'INHERITED CATARACTS
Nuclear sclerosis is a change that takes place inInherited cataracts in dogs may occur on their
the lens of older dogs. It manifests itself physicallyown or may present simultaneously with other
as a graying of the lens of the eye. It typicallydiseases of the eye. Obviously a dog that is
occurs in both of the dogs eyes simultaneouslydiagnosed with inherited cataracts should not be
and usually occurs in dogs that have reached sixused for breeding.
years of age or more. While its appearance isTRAUMA INDUCED CATARACTS
worrisome Nuclear sclerosis does not greatlyTrauma resulting from; a head injury, scratch or
affect the vision of the dog and treatment is notpuncture to the eye surface, shotgun pellet, may
generally recommended.damage the lens, resulting in cataract. These
HOW DOG CATARACTS DEVELOPcataracts can be very aggressive in their
All canine cataracts develop in a similar fashiondevelopment; within days of the given trauma the
although there are various causes. A normal dogwhite milky appearance may be visible to the
eye is actually maintained in what is referred toowner or tending veterinarian.
as a dehydrated state. That is to say it consistsDIABETIC INDUCED CATARCTS
of 66% water and 33% protein. There is anWhen there is excess sugar in the eye fluids,
intricate sodium water pump system in the lensthere is excess sorbitol produced. Sorbitol pulls
that maintains the all important water/proteinwater into the lens which in turn disrupts lens
balance. When this intricate water pump system inclarity and causes the cataract. Fructose is also
the lens is damaged, the balance alters and extraproduced from the excess glucose and also
water moves into the lens. This is accompaniedcontributes to the problem. Unfortunately these
by an increase in the percentage of insolublecan be very aggressive cataracts and can induce
protein. These changes result in the cataractblindness in a matter of weeks or months in the
formation and the associated loss ofaffected dog.
transparency.This article is free to republish provided the
AGE OF ONSETauthors resource box remains intact.
The age at which a dog shows signs of