Retinal Dysplasia is a congenital (i.e. present at birth) but non-progressive disorder of the eye in which the retina develops abnormally, causing folds or clumps (known as rosettes) to develop or in the most severe cases, detachment of the retina.
The retina is the lining at the back of the eye that captures light and transmits it as electrical signals to the brain. The brain then interprets the electrical signals into images; in effect the retina acts as a camera for the brain. The retina is formed of two layers which should develop together. If the layers do not develop together folds or “rosettes” will form and this can result in varying degrees of visual impairment, from mild impairment that’s barely noticeable, through to very definite blind spots and in the most severe cases, blindness.
Retinal Dysplasia Disorder can either be inherited or acquired:
1. Inherited Retinal Dysplasia: This condition can be inherited via a genetic defect passed on from one or both of the puppy’s parents.
A number of breeds have a predisposition to genetic inheritance of Retinal Dysplasia and these include, but are not limited to: Afghan Hound, Airedale Terrier, Akita, American Cocker Spaniel, American Water Spaniel, Australian Cattle Dog, Australian Shepherd, Australian Terrier, Basenji, Beagle, Bedlington Terrier, Belgian Malinois, Belgian Sheepdog, Border Terrier, Brittany, Bull Mastiff, Cardigan Welsh Corgi, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Clumber Spaniel, Collie (rough And Smooth), Doberman Pinscher, English (British) Bulldog, English Cocker Spaniel, English Springer Spaniel, English Toy Spaniel, Field Spaniel, German Shepherd, Golden Retriever, Gordon Setter, Great Dane, Havanese, Irish Wolfhound, Labrador Retriever, Maltese Terrier, Mastiff, Newfoundland, Norwegian Elkhound, Old English Sheepdog, Pembroke Welsh Corgi, Poodle (Toy, Miniature and Standard), Puli, Rottweiler, Saint Bernard, Samoyed, Schnauzer (Miniature, Standard and Giant), Sealyham Terrier, Shih Tzu, Soft Coated Wheaten Terrier, Sussex Spaniel, Tibetan Spaniel, Tibetan Terrier, West Highland White Terrier, Yorkshire Terrier
In most breeds the defective gene is believed to be passed on in an Autosomal Recessive inheritance pattern, which means that if the defective gene is inherited from only one parent then the offspring won’t develop Retinal Dysplasia but they will be a carrier and will pass on the defective gene to their own offspring. If both parents have the defective gene, the offspring will develop Retinal Dysplasia.
2. Acquired Retinal Dysplasia: This condition can be acquired as a result of a viral infection, such as canine herpes, being contracted by the mother during pregnancy. It can also be acquired as a result of damage or trauma to the puppy’s eye before it is born. In addition, there is believed to be some correlation between Vitamin A deficiency and Retinal Dysplasia but this isn’t certain and hasn’t been confirmed scientifically.
Retinal Dysplasia comes in three forms:
- Focal or Multi-Focal Dysplasia:
This is the mildest form of dysplasia in which folds or rosettes develop in one or more areas of the inner retinal layer. As the puppy grows and develops, these folds may become less severe, however the dog could still be left with some visual impairment, such as blind spots. The degree of impairment will vary from dog to dog.
- Geographic Dysplasia:
This form of Retinal Dysplasia is characterised by horseshoe shaped lesions to the retina. Unlike the folds in Focal Dysplasia, these lesions will not lessen over time. Geographic Dysplasia results in more severe visual impairment and even blindness.
- Complete Retinal Dysplasia:
This is the most severe form of Retinal Dysplasia, where the two layers of the retina do not come together at all resulting in detachment of the retina. Dogs with this condition are completely blind.
There are no obvious signs of Retinal Dysplasia Disorder, but puppies with significant impairment to their vision may exhibit the following signs that all is not well:
- continually bumping into objects, particularly in low light situations
- reluctance to go into darkened rooms and other areas around the home
- reluctance to go up or down stairs
- reluctance to go outside after dark
If your dog shows any of these symptoms it is best to have their eyes checked by your vet.
Note: Puppies with mild retinal dysplasia may show no overt signs of vision impairment at all.
Diagnosis of Retinal Dysplasia Disorder:
The only way to confirm if a dog has Retinal Dysplasia Disorder is by an examination with an opthalmascope, which should be carried out by a qualified vet. The opthalmascope will allow the vet to see any unevenness, folds, lesions, and so forth in the retina.
Note: the disorder may not be properly detectable until the dog reaches 6 months of age, when the retina is fully developed.
Treatment of Retinal Dysplasia Disorder:
There is no treatment for Retinal Dysplasia Disorder, however it is a non-progressive and non-painful condition. This means that the level of visual impairment a dog is born with will remain for the rest of that dog’s life, but they will adapt and they will amaze you with how well they manage by using their remaining senses to compensate for their impaired vision.
Prognosis (Long Term Outcome):
Dogs with this condition can lead perfectly happy, healthy lives with just a few adjustments to allow for their disability, such as not moving furniture around, using stair gates, using scent markers and various other steps that are discussed in more detail in the “Living with a Blind Dog” section of this website.
Further information and recommended reading:
Dog Retinal Dysplasia Disorder
Retinal dysplasia refers to a disorder in which the cells and layer of retinal tissue did not develop properly. It is usually a nonprogressive disease and can be caused by viral infections, drugs, vitamin A deficiency, or genetic defects. The disorder can be inherited, or it can be acquired as a result of a viral infection or some other event before the pups were born. Read more….
For more detailed information on this condition the following websites are well worth a visit:
- Wikipedia.org – Retinal Dysplasia
A basic, but quite useful, description of Retinal Dysplasia in dogs
- eHow.com – Retinal Dysplasia in dogs
A really easy to read article on Retinal Dysplasia in Dogs
- Pets4Homes.co.uk – Retinal Dysplasia in Dogs
A good, easy to read article on Retinal Dysplasia in dogs.
***Probably the best article to read for those who don’t want too much technical jargon but who need to understand exactly what Retinal Dysplasia is***
- Provet.co.uk – Retinal Dysplasia
A good description of Retinal Dysplasia without too much technical jargon. Small font size makes it a bit tough on the eyes but it’s laid out well, so it’s actually quite easy to read – and there’s always the zoom function on your computer if you’re struggling with the font size
- upei.ca – Retinal Dysplasia
A straightforward, easy to follow article on Retinal Dysplasia in dogs. Strikes a good balance between detail and technical jargon. Plenty of information, but not too technical for those of us who want to understand Retinal Dysplasia but don’t have a technical background. It also contains a really useful drawing of the structure of the eyeball to aid understanding of the disorder