Dog VKH Syndrome
Vogt-Koyanagi-Harada-like Syndrome is an immune mediated disease with severe autoaggression against melanocytes that are the pigment producing cells of the skin and eyes (iris). Named after the three scientists who detected this disease in humans, the VKH-Like syndrome appears in canines. Also known as Uveodermatologic Syndrome (UDS or UV Syndrome), this disease appears more commonly in males. Dogs suffering from UDS include Nordic breeds, Samoyed, Siberian Husky, Alaskan Malamute, Saint Bernard, Old English Sheepdog, Irish Setter, Golden Retriever, Chow Chow, Shetland Sheepdog, and Akita.
UDS causes severe Uveitis, the inflammation of the uveal tract. Uveitis is one of the Akita’s worst diseases and can result in blindness.
The cause of UDS is unknown, as yet. The age of onset may range from thirteen months to six years.
Symptoms and Diagnosis
One of the most prominent symptoms of UDS is Uveitis. The canine may experience painful and/or bloodshot eyes. As the eyes bulge with internal pressure, the retinas can detach, leading to acute blindness. Signs include diminished vision, cloudy eyes, constricted pupils and changes in eye color. Chronic Uveitis may involve cataract formation or development of glaucoma that can also result in blindness. Hair loss can occur around eyes, muzzle and anus. The mucus membranes may seem crusty.
Three to six months after the eye disease starts, dogs can experience a loss of pigmentation. Whitening of coats affects 90% of dogs. Poliosis may begin within two weeks of Uveitis and may take several months to develop as it affects the face. Vitiligo or whitening of the skin, as on the eyelids, footpads, lips, nose and scrotum appears on 50% of dogs. Exposure to sunlight may worse symptoms.
Diagnosis involves a skin biopsy in which speed is of the essence. Through prompt diagnosis, effective treatment can be applied to uveitis. Severe conjunctivitis may be a starting point after a sudden stressful event. The severity can differ between individual dogs.
Treatment of UDS can focus on the eye disease. Oral and topical treatment includes corticosteroids and prednisone to suppress inflammation. Controlling eye pain is also a focus. Continued treatment may involve steroid-containing eye drops or steroid injection. Preventing blindness may call for immune suppression and azathioprine. A detached retina can reattach and offer some sight restoration.
Canines may suffer recurrent attacks of Uveitis that will damage the retina. The degree of sign restored will gradually reduce. Long-term treatment can act as prevention. Treatments may include immunosuppressive and cytotoxic drugs. The side effects of drugs can make the canine more susceptible to other infections and affect its ability to deal with minor surgery.
Treating auto-immune disease is not a cure, but a way of suppressing of the clinical symptoms. Treatment may allow the canine to enjoy a reasonable quality of life. Dog owners should ensure regular monitoring. With no DNA marker yet detected, this disease and the side effects of drugs will continue to claim the lives of dogs.