The correct name for this disease in dogs is Uveo-Dermatological Syndrome or UDS, but because of the strong similarity to an auto-immune disease in humans it is more often known as VKH (VKH being the initial letters of the three scientists Vogt, Koyanagi and Harada who discovered the disease in humans). VKH in humans
In human beings Vogt-Koyanagi-Harada Syndrome results in the whitening of hair (poliosis), depigmentation of skin (vitiligo), internal inflammation of the eye (uveitis), painful hearing and meningitis. It is therefore sometimes referred to as “uveominingoencephalic syndrome” and it primarily affects 30-40 year old people with black or heavily pigmented skins. The cause is not completely understood, but auto-immune reactions to pigment containing cells, nerve tissues and retinal cells are considered to be important. Neurological signs usually precede the uveitis, and blindness due to retinal detachment may occur. The uveitis may persist for years, and cataract (lens opacity) and glaucoma (high fluid pressure within the eye) will cause blindness in such patients. Alopecia (loss of hair), poliosis and vitiligo develop 2-3 weeks after the uveitis has appeared. Treatment can be very difficult.
VKH in animals
In addition to pigs and chickens, the list of dog breeds affected by a very similar disease includes the Samoyed, the Irish Setter, the Golden Retriever, the Chow-Chow, the Shetland Sheepdog, the Siberian Husky, the Old English Sheepdog and the St Bernard, as well as the Japanese Akita. The neurological features of human VKH are not seen, the lesions being restricted to the skin, hair and eye (vitiligo, poliosis and uveitis). The term VKH is thus not entirely appropriate, and “uveodermatological syndrome” is preferred. The incidence of the disease in the Akita would appear to be increasing both in the USA and in the UK though accurate incidence figures are unknown.
VKH, or Uveo Dematological Syndrome, is one of the worst diseases found in Akitas. It affects eyes, with most (though not all) dogs eventually becoming blind. Most often it seems to start with a severe conjunctivitis and often follows a sudden stressful period. The affected eyes are extremely painful, bulging with internal pressure, and the retinas detach, resulting in many cases in permanent blindness. However, as with many diseases both in humans and animals, the degree of severity varies from individual to individual. For reasons that are not understood, the retina in dogs is more resilient than in humans and if treated quickly with the appropriate drugs, can reattach and a reasonable degree of sight can be restored. Since this can recur at irregular intervals, the retina will be damaged on each recurrence, and therefore the degree of sight restored will gradually be reduced. It also affects the skin, with loss of pigmentation, and hair loss around the eyes, muzzle, anus and these mucous membrane areas can also become “crusty”.
In dogs, the disease itself is not life threatening, but blindness is not unusual. The uveitis varies in severity and prompt diagnosis can result in relatively effective treatment. Acute blindness is due to retinal detachment, whereas chronic uveitis can lead to blindness as the result of cataract formation or the development of glaucoma. Poliosis and vitiligo usually begin within 2 weeks of the uveitis, but it may take several months to develop. Poliosis involves the face, and the eyelids, the nose, the lips, the scrotum and the footpads may be involved in vitiligo. Occasionally, the vitiligo may involve the whole body, and the depigmentation areas may ulcerate. Loss of hair may occur, but not all patients will be involved.
As with humans the precise nature of the cause of the disease is unknown, although VKH is believed to be caused by a recessive gene, but until a DNA marker is found this is not yet proven. Treatment can be difficult. Speedy and prompt diagnosis is essential, and many vets will refer the patient to an ophthalmic specialist who is more familiar with the disease. Topical and systemic corticosteroids are usually used. Long-term treatment is often essential to prevent recurrent attacks, and other treatments involving immunosuppressive and cytotoxic drugs may have to be tried. It is important to remember that canine patients undergoing treatment for auto-immune disease are very often not going to be cured but rather have the clinical signs of the disease suppressed by use of the drugs. The aim of this treatment is to ensure a reasonable quality of life for the dog, but a great deal of ongoing owner dedication is required in the management.
The drugs used are themselves not without side effects; many will reduce the dog’s ability to deal with minor surgery, make the animal more susceptible to other infections or produce side effects which cannot be controlled and therefore make their use unsuitable in that particular patient. Regular monitoring is essential for the dog’s continued wellbeing. Veterinarians will advise regarding suitable monitoring regimes. It is really important to observe these and to take your dog back to the vet when requested to do so. In many cases, euthanasia is the result of the side effects of the drugs rather than the direct effects of the disease itself.
“The literature indicates a breed disposition but the mechanism of inheritance remains unknown at this time. Awareness of the disease should lead to prompt treatment with, hopefully, the prevention of blindness. At this moment the avoidance of affected animals in breeding programmes is a sensible step.” – Prof. PGC Bedford
Around the world
Dogs in England who have/had this disease share many relations in common with dogs in other countries. Affected dogs have also been found in South Australia, Queensland, Sweden, United States and Canada (New Zealand currently appears to be unaffected though there are related dogs there too.) The disease was first seen in Akitas in America, and is on the increase there. It is understood that Akitas in Japan are also known to have VKH, but we don’t have any details.
Until a DNA marker can be found then dogs around the world will continue to die from this horrid disease or from the side effects of medications used to control it. For some time a small group of people – Alison Blair in New Zealand, Bea Pitts in England, and Les Ray in Australia, have been working together to raise awareness of VKH with an ultimate goal of helping to raise funds and DNA samples for research. Through their efforts arrangements have been made for blood samples from affected and/or related dogs to be donated to the Animal Health Trust at Newmarket, Suffolk, England. DNA will be extracted from the blood samples and frozen ready for use when research begins.
The sudden untimely death of Alison Blair has caused many people around the world to express a need to do something to honour her memory. It was Alison’s dearest wish that researchers in England be permitted the opportunity to make a start where researchers at UC Davis in California left off earlier in 1999 and researchers from both sides of the Atlantic have already met and collaboration has been promised – all that prevents them from proceeding is lack of funding.
With this in mind, and with Alison’s dearest wish at heart, the Alison Blair Memorial Fund has been started, to raise funds for research into VKH in Akitas. Anybody wishing to donate to this fund should note that all payments should be made in pounds sterling payable to “Alison Blair Memorial Fund” at the following bank address:
|Bank Sorting Code:||05-03-57|
|Account Name:||Alison Blair Memorial Fund|
|Bank:||Yorkshire Bank plc|
|1 Market Place|
|Cannock WS11 1BT|
Alison was someone who probably did not know the impact she made on many people around the world. We often go about our daily routines – answering emails, discussing causes, not realising how our words and deeds do matter. If you want to donate to the Alison Blair Memorial Fund, please send your cheque today. Let’s hope we can carry on a small part of her wishes to help our beloved breed and those affected by VKH.