Eye disorders in the Siberian Husky are serious and should not be understated or overlooked. They may occur in any eye color. 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 spay or neutered.
Hereditary or juvenile cataracts (JC) are manifested by opacity in the lens of a young dog as early as 3 months of age. The eye with the cataract(s) has a cloudiness of the lens of the eye. The purpose of the lens is to focus the rays of light so that they may form 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.
One or both eyes may be affected and the cataracts may not appear in both eyes at the same time. It is not uncommon for a cataract to develop in one eye months before the other eye shows the effects of the disease. 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. Recent DNA research indicates that juvenile cataracts may be carried by a recessive gene.
Non-hereditary cataracts affect aged or senior dogs or may result from injury, inoculation reactions, eye infections, or systemic infections.
Corneal dystrophy (CD) affects the cornea or the outer transparent portion of the eyeball. In most cases, Siberian Huskies with this disorder have an abnormal collection of lipids in the clear cornea of the eye which results in a hazy or crystalline opacity.Corneal dystrophy is usually seen in young adult dogs and may affect females more than males. Vision may be affected and no effective therapy for the condition exists at this time. Recent genetic tests are suggesting that a recessive gene with variant expression transmits this disorder.
Progressive retinal atrophy (PRA) affects the retina, the light-sensitive inner lining of the posterior part of the eyeball. The retina contains two types of specialized cells called rods and cones. The rods are necessary for sight in dim light or night light, and the cones are utilized in in bright light vision. The Siberian Husky has a unique type of PRA that is only found in Siberians and man. This type of PRA is called XLPRA (X Linked PRA) since it is transmitted through the "XX" chromosome of the female. It will cause a loss of night vision followed by a loss of day vision, eventually blindness. The recessive gene for XLPRA is situated on the "X" chromosome of the female. Females who inherit a defective gene on the "X" chromosome from one parent and a normal gene on the other "X" chromosome from the other parent, will not be seriously affected. They will be carriers with very subtle retinal defects and no loss of vision. The male puppy from a carrier dam will receive either a defective gene or a normal gene, depending on what chromosome was copied in the DNA replication. If he has the defective gene, the dog will be affected with PRA since males carry an "XY" chromosome. The disease in males can be devastating with loss of vision as early as 5 months of age.
How are eye defects diagnosed?
Accurate diagnosis of eye defects requires the expertise of a board certified veterinary ophthalmologist who is equipped by knowledge and training to distinguish hereditary eye diseases from non-hereditary eye disorders. The American College of Veterinary Ophthalmologists (ACVO)is the national governing board for the certification of veterinary ophthalmologists. Since 1974, the SHCA has encouraged local breed clubs to support eye clinics, which make eye examination more convenient and affordable to breeders and dog owners. Today, thanks to the devotion and support of local area clubs, eye clinics are common throughout the country and are available to all breeders.
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.