Post by muskyhusky on Oct 17, 2008 14:43:46 GMT -6
Progressive Retinal Atrophy (or PRA)
There are many inherited eye disorders in all breeds of dogs but the most prevalent ones in the Siberian Husky are Juvenile Cataracts (commonly referred to as JC), Corneal Dystrophy (or CD) and Progressive Retinal Atrophy (or PRA)
Even with years of study, breeders have not been as fortunate with the eradication of inherited eye disorders and their causes as with Hip Dysplasia. The only thing breeders have available is the ability to examine our breeding stock and not use those animals who are afflicted. The one thing we are sure of is that these three disorders are definitely inherited and afflicted dogs should not be bred. We will try to explain, in basic term, each of these three eye disorders.
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Juvenile Cataracts (JC) - Called "juvenile cataracts" to differentiate them from the "old age" type cataract or from the degenerative type that results from injury, inoculation reactions or systemic disease. The eye with the cataract(s) has a cloudiness of the lens of the eye in a relatively young dog. The purpose of the lens is to focus the rays of light so that they may forma an image on the retina. If the lens becomes cloudy then less light can enter the eye and the sight will slowly diminish as the cataract becomes larger.
This type of cataract will show up at an early age and in most cases is inherited. One or both eyes may be affected and the cataracts may not appear in both eyes at the same time. At this time there is no proof that eye color has any bearing on the likelihood of developing juvenile cataracts. Many dogs with juvenile cataracts can lead normal lives well into their older senior years before the cataracts impair their vision dramatically. Unfortunately, in some instances the cataracts are severe enough to cause blindness at a young age.
Corneal Dystrophy (CD) - This eye disorder affects the cornea and causes a gray haze and/or needle-like crystals to form in the cornea, eventually spreading across the surface of the eye and sometimes totally obscuring the vision of the dog. As with JC, both eyes may not become affected at the same time and the disorder does not discriminate with regard to age.
Progressive Retinal Atrophy (PRA)- The retina has two types of cells, the rods which are used for sight in darkness and semi-darkness and the cones which are used in bright light such as daylight. PRA affects the retina and there are two types of PRA, primary retinal dystrophy and central progressive atrophy. Both forms of PRA can occur at any age.
The most common type of PRA is primary retinal dystrophy in which dogs first lose their night vision as the rod cells atrophy, followed by their loss of day vision as the cone cells deteriorate. This particular type of PRA is progressive and will eventually result in total blindness.
With central progressive atrophy the dog has better dim light vision than bright light vision because it causes a blind patch in the central field of vision. With this type of PRA the dog may bump into large unmoving items such as furniture but they can see moving objects very well. This form of PRA is also progressive and while total blindness may not occur, the severity of the disease may cause problems for the dog and family and will be the cause of many adjustments as the dog grows older.
There is no known "cure" for the eye disorders described once the dog becomes afflicted. Medical intervention may help with some forms of eye disorders but not all.
Responsible breeders will have all their breeding stock examined by a Certified Canine Ophthalmologist on a yearly basis and any dog who is shown to be afflicted will be removed from their breeding program. Breeders are willing to show you proof of a recent eye examination and/or CERF or SHOR registration.
www.offa.org/index.html
There are many inherited eye disorders in all breeds of dogs but the most prevalent ones in the Siberian Husky are Juvenile Cataracts (commonly referred to as JC), Corneal Dystrophy (or CD) and Progressive Retinal Atrophy (or PRA)
Even with years of study, breeders have not been as fortunate with the eradication of inherited eye disorders and their causes as with Hip Dysplasia. The only thing breeders have available is the ability to examine our breeding stock and not use those animals who are afflicted. The one thing we are sure of is that these three disorders are definitely inherited and afflicted dogs should not be bred. We will try to explain, in basic term, each of these three eye disorders.
--------------------------------------------------------------------------------
Juvenile Cataracts (JC) - Called "juvenile cataracts" to differentiate them from the "old age" type cataract or from the degenerative type that results from injury, inoculation reactions or systemic disease. The eye with the cataract(s) has a cloudiness of the lens of the eye in a relatively young dog. The purpose of the lens is to focus the rays of light so that they may forma an image on the retina. If the lens becomes cloudy then less light can enter the eye and the sight will slowly diminish as the cataract becomes larger.
This type of cataract will show up at an early age and in most cases is inherited. One or both eyes may be affected and the cataracts may not appear in both eyes at the same time. At this time there is no proof that eye color has any bearing on the likelihood of developing juvenile cataracts. Many dogs with juvenile cataracts can lead normal lives well into their older senior years before the cataracts impair their vision dramatically. Unfortunately, in some instances the cataracts are severe enough to cause blindness at a young age.
Corneal Dystrophy (CD) - This eye disorder affects the cornea and causes a gray haze and/or needle-like crystals to form in the cornea, eventually spreading across the surface of the eye and sometimes totally obscuring the vision of the dog. As with JC, both eyes may not become affected at the same time and the disorder does not discriminate with regard to age.
Progressive Retinal Atrophy (PRA)- The retina has two types of cells, the rods which are used for sight in darkness and semi-darkness and the cones which are used in bright light such as daylight. PRA affects the retina and there are two types of PRA, primary retinal dystrophy and central progressive atrophy. Both forms of PRA can occur at any age.
The most common type of PRA is primary retinal dystrophy in which dogs first lose their night vision as the rod cells atrophy, followed by their loss of day vision as the cone cells deteriorate. This particular type of PRA is progressive and will eventually result in total blindness.
With central progressive atrophy the dog has better dim light vision than bright light vision because it causes a blind patch in the central field of vision. With this type of PRA the dog may bump into large unmoving items such as furniture but they can see moving objects very well. This form of PRA is also progressive and while total blindness may not occur, the severity of the disease may cause problems for the dog and family and will be the cause of many adjustments as the dog grows older.
There is no known "cure" for the eye disorders described once the dog becomes afflicted. Medical intervention may help with some forms of eye disorders but not all.
Responsible breeders will have all their breeding stock examined by a Certified Canine Ophthalmologist on a yearly basis and any dog who is shown to be afflicted will be removed from their breeding program. Breeders are willing to show you proof of a recent eye examination and/or CERF or SHOR registration.
www.offa.org/index.html
