Vitiligo or Leucoderma in Pets & Livestock
This is an auto immune disorder, which is rare in dogs, cats, horses. It is an uncommon skin condition that can cause the skin to lose its pigmentation this process called as depigmentation. Vitiligo is a condition that skin turns into white. Even for humans also face this situation. Although this condition is painless and need not to be worry. In this condition the dog looks like white patchy under skin.
VITILIGO CAN BE DEFINED AS A RARE AUTOIMMUNE DISEASE thought to selectively destroy epidermal melanocytes, leading to loss of pigment in the affected area (Paterson, 2008). Clinically this leads to patchy areas of depigmented skin (leukoderma) or hair (leukotrichia). The disease is uncommon in the dog and rare in the cat.
Vitiligo is a skin condition characterised by spontaneous loss of melanin has been described in several animals. Vitiligo or leukoderma progress slowly and condition is uncommon in buffaloes. Etiology of vitiligo is unknown occur in dark and brown skinned varieties of buffaloes. ( Cockrill, 1974). Vitiligo is a skin condition due to deficiency of copper. Abnormal hair pigmentation may be occur due to decreased tyrosinase activity resulting in decreased conversion of tyrosine to melanine.
The disease is causing heavy economic losses to animal owners due to substantial reduction in market value. Leukoderma means loss of normal skin pigmentation (Radostits et al., 2007). It may be congenital or acquired. Congenital or hereditary leukoderma develops due to lack of melanocytes or failure of melanocytes to produce melanin or failure of transfer of melanin to epidermal cells. It can also be acquired through loss of existing melanin or melanocytes (depigmentation). The exact mechanism of depigmentation of skin includes breakdown in the conversion of tyrosine to melanin because of reduced tyrosinase activityresulting in achromotrichia and leukoderma in copper deficiency (Underwood, 1977). Leukoderma is a common skin disease of man in tropical countries (Manson-Bahr, 1960), however it is rare in domestic animals. The clinical cases of chronic skin disease in buffalo characterised by whitish discolouration of skin and refractive to the acaricides, antibiotics, antihistaminics and corticosteroids are being reported by field veterinarians and animal owners from Marathwada region of India. The disease is causing heavy economic losses to animal owners as it is reducing the market value of buffaloes by 50 to 60 percent due to misbelieves amongst people that the consumption of milk from affected buffaloes is hazardous for human health and few people are of strong opinion that leprosy may be contracted from drinking of milk and eating of flesh of affected buffaloes.
Vitiligo is a progressive disease of skin in which melanocytes are gradually destroyed causing depigmentation. It is most commonly acquired hypomelanosis in human. Elephant, horses, dogs, poultry and buffaloes are animal species in which Vitiligo has been recorded. In buffaloes depigmentation starts around brisket and and may extend up to neck, abdomen, and flanks. In majority of cases hypomelanosis starts with destruction of melanocytes first in epidermal compartment and latter in follicular reservoir where most melanocytic stem cell are sitiuated. (Alain Taieb). The ultrastructural skin changes seen in animal closely resemble human cases (R.cerundolo et el.).
The aetiology of Vitiligo is unknown, but auto-immune, neural, self destruct, growth factor defect, and copper deficiency (P.N.Takker and Randhawa) hypothesis have been suggested. The treatment of vitiligo in human may take as long as six to eighteen months. Topical cortico-steriods and immunomodulators, ultra voilet A and narrow band ultra voilet B depigmentation, skin grafts are commonly used to treat human cases. No treatment for animal have been recommended, perhaps due to absence of cutaneous or systemic pathology except unsightly appearence. Vitiligo is an uncommon skin condition that causes skin to lose its natural pigment, a process called depigmentation. In addition to affecting the skin, vitiligo can also cause hair to turn white. Like humans, dogs and cats can develop vitiligo. Although your dog or cat may start to look a little funny with patches of white skin and fur, there is no need to worry. Vitiligo is painless and won’t bother your pet at all.
Pathogenesis
Antimelanocyte antibodies were demonstrated in 17 Belgian Tervuren dogs with Vitiligo and in none of 11 normal dogs of that breed. Similarly, three affected Siamese cats with Vitiligo had antimelanocyte antibodies while four normal Siamese cats did not (Naughton and others, 1986). There has beenv little information on the pathogenesis in companion animals since this article was published. A case of generalised Vitiligo has been described in a dog with primary hypoadrenocorticism (Malerba and others, 2015). The authors concluded that dogs with immunemediated disease might develop other manifestations of this group of disorders including a combination of Addison’s disease/Vitiligo. There is also a recent case report of depigmentation associated with the administration of toceranib in a Bernese mountain dog (Cavalcanti and others, 2017).
Clinical features
- There is no sex predilection.
- More commonly seen in young dogs.
- Lesions occur mainly on the nose
- Any breed may be affected, but there are some predisposed breeds. These include the Belgian Tervuren, German shepherd, Collie, Rottweiler, Doberman pinscher and Giant Schnauzer (Hnilica and Patterson, 2017).
- Lesions in the cat are similar but rarer, with Siamese cats predisposed.
Causes of Vitiligo in Dogs and Cats
No one understands exactly what causes melanocytes to be altered or damaged in the absence of trauma, resulting in vitiligo’s characteristic lightened patches.
The most likely causes include:
- Genetics–a hereditary condition in dogs that have a familial history of the disorder
- Autoimmune disease in which a dog’s tissues are damaged by its immune system
While any dog, including mixed breeds, can develop vitiligo, certain dog breeds may be at a higher risk of developing it, including-
- Belgian Tervuren
- German shepherd
- Doberman pinschers
- Rottweilers
- German shorthaired pointers
- Old English sheepdogs
- Miniature dachshunds
- Giant schnauzers
- Collies
- Beauceron shepherds
- Newfoundlands
- Bernese mountain dogs
The skin contains cells called melanocytes that produce melanin, the pigment that gives skin its color. Vitiligo occurs when melanocytes are destroyed or die off.
Sometimes, vitiligo can be caused by an autoimmune disease. Autoimmune diseases cause the immune system to attack the body instead of foreign substances. With vitiligo, an autoimmune disease attacks and destroys melanocytes.
Other potential causes of vitiligo are stress, exposure to toxins, and neurologic disease. The stress may be due to an underlying medical condition that’s causing discomfort.
Types of Vitiligo
Vitiligo can be categorized into two main types:
- Focal vitiligo affects only one area. In dogs, vitiligo that affects only the nose is called “snow nose.”
- Generalized vitiligo causes multiple white patches in random or symmetric patterns across the body. In cats, generalized vitiligo can become so extensive that it produces a “cobweb” or “snowflake” appearance of white fur.
Symptoms of Vitiligo
In dogs and cats, vitiligo starts at a young age and progressively destroys melanocytes. As the melanocytes die off, the skin in the affected area turns white or pink. The fur covering the affected skin also turns white.
Vitiligo commonly affects the face first, particularly the nose. Other areas of the face that might lose pigment include the lips and the area around the eyes.
Vitiligo that spreads beyond the face can affect the footpads and other parts of the body. The full extent of the spread, if any, will occur within three to six months of the first appearance of vitiligo. Once the affected areas turn white, they might stay that way, re-pigment, or even wax and wane.
If you have a cat, take note that vitiligo is more easily noticeable in black cats but can affect cats of any color.
Inflammation, skin lesions, and dander are rare in body areas affected by vitiligo.
Diagnosis
If you notice your dog or cat’s fur is suddenly starting to turn white, take your pet to your veterinarian for further examination. It will be important to determine if there is a medical condition causing the depigmentation.
During the appointment, let your veterinarian know when you first noticed the vitiligo and where it first appeared on your pet’s body. Because stress may cause vitiligo, tell your veterinarian if your pet has been more stressed than usual at home.
After taking a close look at your pet’s skin and fur, your veterinarian will perform a few diagnostic tests. She will take a blood sample to rule out medical causes of vitiligo. Your veterinarian will also take a skin scraping from an affected area and look at the skin sample under the microscope. To get an even closer at the skin, your veterinarian might take a skin biopsy, which would show a lack of melanocytes in the affected area.
Treatment and Management
Currently, there are no available treatments for vitiligo that will re-pigment your pet’s affected skin and fur. However, because vitiligo causes no discomfort, your dog or cat will be just fine living the rest of his or her life with this condition.
There are several management options for vitiligo that you can discuss with your veterinarian. For example, some veterinarians recommend increasing exposure to the sun to stimulate production of new melanocytes. If blood tests revealed a medical cause of your pet’s vitiligo, your veterinarian will prescribe treatments for that medical condition. Reducing stress, whether by making the home environment less stressful or treating the underlying medical condition, may improve vitiligo.
If the sight of white patches is bothersome to you, consider asking your veterinarian to tattoo the areas of depigmented skin.
It has been suggested that supplementing a pet’s diet with omega-3 fatty acids and vitamin C can help manage vitiligo. However, to date, there is little research evidence to support nutritional supplementation for dogs and cats with vitiligo. Talk to your veterinarian about supplementing your pet’s diet.
It’s certainly understandable if it takes you some time to adjust to your dog or cat’s new look. Just remember that the new look is completely cosmetic and doesn’t have to change just how much you love and care for your pet.
Treatment
There is no effective treatment protocol for a dog with vitiligo, but concerned pet owners sometimes try treatments that have been used in people with the same skin disorder.
Topical immunosuppressive medications and ultraviolet phototherapy are two options that can be discussed with your veterinarian, but the results are usually unimpressive.
Since vitiligo is not a painful disorder and it does not interfere with a dog’s daily life, most pet owners opt not to pursue treatments, especially since they are costly, lack efficacy, and may even be dangerous to a dog’s health
Animals like Buffaloes are treated with copper sulphate @ 8 gm orally once in a week for 4-8 weeks and the white patches slowly regresses after supplimentation.
DR RB SHAW,LUCKNOW
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