Issue Description In UDS the autoimmune reaction is directed
against the melanocytes (the pigment-producing cells) of both skin and
eyes (iris). The disease causes severe uveitis but early diagnosis and
therapy may prevent serious vision loss. In the the skin it most
commonly causes depigmentation (Vitiligo) of the periocular region,
lips and nose. Other Names VKH Syndrome, Vogt-Koyanagi-Harada Syndrome, UDS
Causes Vogt-Koyanagi-Harada-like syndrome (VKH) is a
rare, idiopathic and autoimmune disease in dogs. The exact cause of
this syndrome is still unknown both in people and dogs.
in other autoimmune diseases there are several causes that may trigger
the syndrome (e.g. stress). It is also speculated that the
immune-reaction is initially triggered by a virus, but there is no
Although the condition has been reported in many different breeds of
dogs, UDS is predisposed in following breeds and their crosses:
The disease is more common in male dogs than female dogs. The age of
onset ranges form 13 months to 6 years.
Symptoms Often the first noticeable sign of UDS is
uveitis. The skin and hair changes typically follow within three to
six months after the eye disease has begun. The changes in hair colour
are seen in some 90% and depigmentation of skin is seen in some 50% of
the affected dogs.
Skin and hair abnormalities are caused
by vitiligo, a depigmentation of skin areas, which seems to be present
in almost every affected dog. The most typical areas of vitiligo are
periocular region, nose and lips. Sometimes also palate, footpads,
vulva, scrotum and anus are affected.
The hair changes are
whitening of patches of hair and hair loss. The skin and hair changes
are mainly a cosmetic concern but sometimes erythema, ulceration, and
crusting of skin is present. Pruritus may be a feature and
lymphadenopathy is common.
Dogs with UDS have various
degrees of uveitis involving iris, ciliary body and choroids. The
uveitis may be very painful and the changes may appear as bloodshot
eyes, constricted pupils, cloudy eyes or changes in eye color.
Conjunctivitis will often be followed by a detached retina, which
shows as a milky blue surface on the eye ball. Unlike in the human
disease, deafness and meningitis are not a feature in dogs.
Diagnosis The best way to confirm this diagnosis is by a
skin biopsy (the lip is said to be the best location). Treatment,
however, is focused on the eye disease as this has the most serious
outcome - blindness - while the skin disease is generally cosmetic.
Treatment Because the eye disease has the most serious
outcome (blindness) and the skin disease is typically only a cosmetic
concern, treatment then focuses on the eye disease. As in other
autoimmune diseases, the primary goal of therapy is to suppress the
body's immune response with large doses of systemic
glucocorticosteroids such as prednisone. To prevent blindness,
on-going immune suppression is needed and more potent drugs like
Cytoxan, Azathioprine or Imuran are used if steroids fail. Continued
topical treatment is also needed, usually with steroid-containing eye
drops or steroid injection. Controlling eye pain may also be required.
In cases where vitiligo has occurred, protecting the affected areas
e.g. with sunblocks may be necessary to prevent the sunburn and
squamous cell carcinoma that may follow.
Prognosis Prognosis is poor overall. The uveitis tends to
recur and may result in permanent blindness due to cataract and
retinal degeneration after long term separation or inflammation. Even
vigorous therapy may not control the situation. 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
In patients in whom inflammation is controlled,
useful vision may be retained and melanosis of the skin may recur.