VOGT-KOYANAGI-HARADA-LIKE SYNDROME IN DOGS
(ALSO CALLED “UVEODERMATOLOGIC SYNDROME”)
True VKH syndrome is a human disease, well described for nearly a century. A similar disease in the dog has been described but since we do not know the relationship between the canine and human disease, we are hesitant to call the canine version “VKH syndrome” as well. Until we know what is really going on in the dog, we will leave it at VKH-LIKE syndrome or, more accurately, “uveodermatologic syndrome.”
A syndrome is a collection of symptoms. In humans, VKH syndrome consists of the following:
Deep inflammation of the eye tissues (a process called “uveitis”) leading to at least artial blindness. Approximately 70% of people with VKH syndrome become blind and it is usually the inflammation in the eyes which appears first.
Human with VKH syndrome, note whitening of the skin
- Premature whitening of the hair (present in 90% of affected people).
- Whitening of the skin (present in 50% of affected people)
- Inflammation of the membranes of the nervous system (a process called “meningitis”). This leads to deafness in about half of the people affected with VKH syndrome.
Affected people are typically of Mediterranean, Hispanic or Asian descent. There are numerous links for more information regarding this condition in humans. Here is a place to start:
The syndrome in the dog includes:
- Uveitis leading to blindness which, as in humans, is usually the first sign to show. The owner would notice that the eyes seem painful and/or bloodshot. The patient may bump into things and show diminished vision. The pupils are classically constricted and the eye may seem cloudy or may seem to change color from normal.
- Whitening of the coat, sometimes confined to the face (present in 90% of affected dogs) This typically begins 3-6 months after the eye disease has started.
- Whitening of the skin, usually most obvious on the nose, lips, eyelids, footpads, and scrotum (occurs in 50% of affected dogs).
Unlike the human disease, deafness/meningitis is not a feature. The most detrimental part of the syndrome is blindness.
Uveodermatologic syndrome is an immune-mediated disease where the body inappropriately attacks its own melanocytes (the pigment-producing cells). These cells seem most prevalent in the skin, retina, and uveal tract of the eye. It is speculated that the immune-reaction is initially triggered by a virus though research is on-going.
- Male dogs are affected more than female dogs.
- Nordic breeds and Akitas are primarily affected.
The best way to confirm this diagnosis is by a skin biopsy (the lip is said to be the best location). Treatment, however, is focussed on the eye disease as this has the most serious outcome (blindness) while the skin disease is generally cosmetic
Uveitis, is most literally inflammation of the uveal tract of the eye. The uveal tract consists of the iris (colored portion of the eye), the ciliary body (the area inside the eye from which the lens is suspended, and the choroid (the vascular coating of the inside of the eye). The treatment for uveitis due to VKH syndrome is the same as for other causes of uveitis.
Thanks to the Animal Ophthalmology Clinic, Ltd. for these pictures. For the complete case study of Sheila, click here.
Uveitis, whether it is caused by VKH-like immune mediated inflammation or something else, is treated by suppression of the inflammation. This means corticosteroids (such as prednisone) orally as well as topically. VKH-like syndrome will require on-going immune suppression to prevent blindness and since long term steroid use is undesirable therapy often switches to azathioprine. Topical therapy is also necessary; steroid containing eye drops or injections of steroids into the conjunctival membranes are commonly used.
With aggressive treatment some dogs are able to regain some vision but, in general, vision cannot be preserved and a more realistic goal is to control the eye pain. Blind dogs still have good quality life as long as pain is controlled. For more information on living with a blind dog visit www.blinddogs.com and sign up for the newsgroup. There is also a blook by Caroline Levin entitled Living with Blind Dogs: A Resource Book and Training Guide for the Owner's of Blind and Low-Vision Dogs. To order it from Amazon.com, click below.
Page last updated: 9/6/2011