Vogt-Koyanagi-Harada Syndrome (VKH Syndrome) is an autoimmune disease in humans where one’s own defence against infection, the T-cells, attack the melanin-forming cells (melanocytes) in the body. Melanin is what gives colour, or pigment, to our hair, skin and parts of our eyes. Since we don’t yet understand how this occurs in dogs, it is most often called VKH-Like Syndrome, or given an altogether different name, Uveodermatological Syndrome (UDS). It is a disease that can be found in a wide range of canine breeds.
The first symptoms occur in the eyes of the dog. A condition called Uveitis, or inflammation of the eye. This inflammation is very painful due to pressure and bulging of the eye. Very bloodshot-looking eyes sometimes can be seen. It may eventually cause partial blindness or total blindness in most dogs, but not all. This happens as a result of the retina becoming detached or other eye complications developing such as cataracts or glaucoma. If caught early enough, the eyes can be treated with proper medication and blindness may be prevented. The next symptom to appear is the whitening of the hair or coat. It is auto-immune related, with hereditary implications. It is felt that any type of stress can trigger the disease. Symptoms are depigmentation, hair loss, and blindness. Sometimes there are no warnings, sometimes there are, like the depigmentation and conjunctivitis (whites of the eye). Conjunctivitis will often be followed by a detached retina, which shows as a milky blue surface on the eye ball. Without treatment, blindness will follow. The dog suffers great pain.
It has also been reported that dogs have been known to lose their nails. The disease affects mucous membrane areas such as the eyelids, mouth, anus, vulva and sometime the pads of the dog’s feet. There is a definite visible loss of pigmentation in these areas, often started by crustiness or blisters. The severities of the symptoms vary from dog to dog. An interesting point to note is that many dogs are often stricken at 18 to 20 months.
A Shiloh Shepherd who was once entirely black, aside from his paws, has turned almost completely snow white due to VKH/UDS
There is no cure for VKH-like syndrome, or UDS. It is believed to be a flaw in the genes. But there are treatments used simply to make the patient more comfortable and obtain a better quality of life. They are mostly focused on the eye symptoms since that can result in blindness. The pigment changes, like the hair turning white, are generally only cosmetic. Steroid drugs are often used as treatment.