Congenital and hereditary skin diseases in cats. Skin pigmentation in animals

The condition of the skin and coat is the first thing owners and veterinarians pay attention to when they see a cat. This is a good indicator of your pet's health. But not every owner knows how to react if the color of the skin or hair suddenly changes.

With various anomalies, both darkening and discoloration of the integument can be observed. Sometimes a change in color is caused by congenital causes, but more often it is the result of external factors or diseases affecting the body.

Local hyperpigmentation

In young animals, spotted melanosis (black spots) occurs, which does not cause any problems other than a cosmetic defect and does not require treatment. In medicine, such lesions are called lentigo.

The breed predisposition is noted in red-colored cats, regardless of the length and quality of the coat. Small uniform black spots 1-9 cm in diameter appear in kittens under the age of 1 year. Most often they are found in the lips and nose, on the gums and eyelids.

Many animals grow dark hair in places that have been shaved (for example, for surgery). Also, dark hair grows at the site of inflammatory alopecia after successful treatment of skin problems. The hair can then return to its normal color after the next cycle of the hair follicle.

In older animals, tumor processes must be excluded. Many different neoplasms can look like pigmented lesions:

• melanoma;
• basalioma;
• mastocytoma.

Acromelanosis in cats

In cats of some breeds, the color of the coat is regulated by special heat-labile enzymes. In other words, the synthesis of melanin in such animals depends on the ambient temperature. Heat promotes the appearance of blond hair, and cold - dark.

Breeders should know this feature when preparing pets for the exhibition. Color change under the influence of temperature is characteristic of cats with "painted" paws:

• Himalayan;
• and some other breeds.

It is known that in these breeds the darkening of the coat increases with age, which is especially noticeable in some colors (color-point).

Hypopigmentation (lightening)

There are several genetic diseases in cats that result in a lack of pigment in the hair and skin. They are quite rare and not treatable:

• In blue-smoky cats with yellow eyes, this is Chediak-Higashi syndrome. This disease causes not only discoloration of the coat, but also partial albinism of the eyes, photophobia and cataracts.
• Siamese cats (more often females) have vitiligo. In young animals, progressive patchy depigmentation of the nose, lips, eyelids, paw pads, and perianal area is observed. Although such cats cannot be used for breeding, vitiligo does not prevent pets from leading a full life.

Acquired lack of pigment can occur under the influence of any factors that destroy melanocytes:

• trauma;
• burns;
• frostbite;
• or a fungal infection of the skin;
• the use of certain medications (glucocorticoids).

Formidable cancers - lymphoma, squamous cell carcinoma - can look like vitiligo.

Other causes of color change

Changes in coat color are especially noticeable on cats of a “radical” suit - or.

• Black cats can fade in the sun, due to which the fur becomes brown, reddish.
• The same effect is observed with a lack of certain amino acids in the pet's diet (tyrosine, phenylalanine).
• Too little copper in food causes hair discoloration.
• In addition, cats, like people, can go gray with - this is most noticeable on dark colors.

All free range cats are affected. At the same time, the color of the skin changes, becoming dark. This is a real tan, enhanced production of melanin as a protection against aggressive radiation.

In light colored animals, the real problem is redness or yellowing of the coat in areas that are exposed to saliva or tears. These are dark lines on the muzzle, typical of Persians, or darkening of the paws with excessive grooming.

• An increased intake of copper and carotenoids (natural dyes) causes an undesirable darkening of light colors.
• Another micronutrient that affects coat color is iodine. They are rich in algae (kelp is often included in cat food). Iodine enhances the red color and can be very beneficial for red or chocolate colored pets. But black and white cats should not be given kelp - a rusty tint will appear.

Ways to improve pigmentation

The fight for the perfect coat color is mainly for those who exhibit their young pets in order to participate in breeding. For each color, special shampoos and conditioners have been developed to enhance the natural color of the coat. This washing is especially important for white cats, which should not have a hint of yellowness.

For white and black individuals, special coloring powders are used before the exhibition. They can be dry or liquid. For especially problematic areas in white cats (chin, tear ducts), gels with a whitening effect have been developed:

• All Systems;
• Super whitening gel.

Touching up is a harmless trick of breeders, giving an effect for no more than a day. To correct the color for a long time, use special food additives.

Suitable for red hair:

• complex Beafar Algolit with seaweed (Beaphar Algolit Vitamin & mineral food supplement);
• GAC-carotene (GAC-carotin) - pure carrot granules containing carotene - provitamin A.

Conclusion

Although the change in coat color is almost always undesirable from an aesthetic point of view, it is usually a completely harmless phenomenon. The color does not always change for life and can return to the previous one after a molt - it depends on the root cause.

Another thing is when a change in skin or coat color is accompanied by alarming signs - itching, inflammation, systemic disorders. In this case, you need to show the pet to the veterinarian as soon as possible and undergo a series of studies to establish an accurate diagnosis.

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Seeing these photos, it's hard to believe your eyes. Is such an incredible color really another victory for breeders? Or is it the result of the skill of cat groomers? It turned out not!

Vitiligo in Scrappy's cat

The owner of the amazing cat Scrappy and his veterinarian believe that the cause of the miracle is an unusual disease that causes a violation of the production of black melanin pigment in certain areas of the skin. The so-called feline vitiligo is extremely rare, but in the human world this disease is far from new.

In the UK, for example, it is fixed in one person out of 100, but in animals, like this black cat, for example, vitiligo is very difficult to find.

At birth, Scrappy was jet black. And it stayed that way for seven years. And then either the sun fell in love with him, or on the contrary, a snowball powdered it. Medicine still cannot identify the exact causes of the disease, although there are prerequisites for believing that the process of disrupting the production of melanin starts after severe stress, with intoxication, and some injuries.

What happened to Scrappi is unknown, but the main thing is that vitiligo did not affect the cat's well-being and his character. He is still kind and affectionate, even though now he is a real star! On Facebook, Scrappy has 60 thousand subscribers, and passers-by do not let him pass. But before they shied away - they say, a black cat, unfortunately.

Despite the unprecedented interest of people in the manifestations of vitiligo in cats - Scrappy's photos on the Web prove this - and the fact that a predisposition to the disease can be inherited, we hope that no one will ever think of breeding a breed of this color. Still, this is a miracle of nature, and miracles should remain unique.

Vitiligo is an acquired skin disease characterized by the destruction of melanocytes and is accompanied by melasma (skin discoloration) and/or leukotrichia (hair discoloration). The exact causes of the development of vitiligo in cats and dogs have not yet been determined, there are several theories with multiple pathophysiological mechanisms. In humans, vitiligo is a multifactorial disease in which different loci of chromosomes (at least 16) may be responsible for the development, they are mostly responsible for the regulation of the immune response, and some of them are also associated with other autoimmune diseases. The study of the pathogenesis of vitiligo in cats and dogs is less advanced than in human medicine, however, when examining 17 dogs of the Belgian Tervuren breed, antibodies to melanocytes were found (in healthy individuals they were not). Also, antibodies to melanocytes have been found in a study of vitiligo in a small number of Siamese cats.

In general, scientists have concluded that the development of vitiligo is caused by some genetic abnormalities that make melanocytes more susceptible to antibody attack and oxidative damage from free radicals.

Clinical signs

Vitiligo is rare in dogs and even rarer in cats. In dogs, vitiligo has been described with possible hereditary transmission in breeds such as the Belgian Tervuren, Rottweiler, Old English Cattle Dog. Cases of vitiligo in dog breeds such as Collie, Doberman Pinscher, Giant Schnauzer, Bullmastiff, Newfoundland, German Shepherd Dog and Dachshund have also been described with the development of diabetes in adulthood. There is speculation that some cases described as idiopathic leukotrichia or nasal depigmentation are actually forms of vitiligo, so the list of predisposed dog breeds can be expanded. In cats, vitiligo has only been described in Siamese breeds, but it is believed that the previously described disease, periocular leukotrichia, is also a form of vitiligo. In Siamese cats with vitiligo, the disease has a slight sexual predisposition to develop in females.

The characteristic localization of lesions in vitiligo of cats and dogs is the nose, lips, buccal mucosa, facial folds and fingertips. Vitiligo externally manifests itself in the form of symmetrical patches of leukoderma and leukotrichia (discoloration of the skin and hair). In most cases of vitiligo, the disease is not characterized by an inflammatory response from the body, but transient erythema and the appearance of crusts may be noted, especially with regard to the development of secondary. Lesions often appear at a young adult age of the animal, pigment loss progresses over several months or years (the latter is rare). In some cases of vitiligo in cats and dogs, spontaneous regression of the lesions may occur, but most often the loss of pigment is permanent.

Diagnosis and differential diagnosis

The diagnosis of vitiligo in cats and dogs is established on the basis of characteristic clinical signs and pathological examination of skin biopsies. On histopathological examination, the epidermis is characterized by a pronounced decrease in the number of melanocytes or their complete absence.

The list of differential diagnoses for vitiligo may include nasal depigmentation, autoimmune lesions (eg, systemic lupus erythematosus), alopecia areata, and post-inflammatory or post-traumatic depigmentation.

Treatment

No reliable treatment for vitiligo has been described in dogs and cats, and a small percentage of the disease may spontaneously regress. With unproven efficacy, ultraviolet irradiation of affected areas can be used in conjunction with the administration of the amino acid L-phenylanine (locally or systemically), this type of treatment is characterized by low cost and a minimum of side effects. In fact, vitiligo in small pets is regarded as a cosmetic defect that does not require treatment.

Valery Shubin, veterinarian, Balakovo

Sourced from www.merckmanuals.com

Cats can be born or inherited with several types of skin conditions. Most of these diseases are very rare, and some are more commonly transmitted among cats of certain breeds.

Hereditary skin diseases in cats.

Aplasia cutis(Aplasia cutis, Epitheliogenesis imperfecta) - the disease can be described as a lack or absence of skin. This is a hereditary disease of unknown nature, in cats, fortunately, is rarely observed. In a sick kitten during fetal development, skin does not form in some areas or even over the entire surface of the body. As a result, the kitten is born with ulcers or no skin on some parts of the body. The disease can be fatal if it affects a large area of ​​the skin. If the affected area is small, surgical correction is possible.

Hereditary lack of hair (alopecia) in cats. A kitten may be born completely or partially hairless. Wool may be lost later as it develops. Such a defect may be accompanied by deviations in the structure of teeth, claws, eyes, as well as skeletal disorders and developmental defects. Hairless breeds of cats, such as the Sphynx, were bred to specifically perpetuate this mutation. All cats with abnormal hair development are prone to infections of the hair follicles (follicles) and inflammation caused by foreign particles entering the hair follicles.

Albinism. It is rare in cats. True albinism is always associated with pink or pale pupils, visible defects, and an increased risk of skin damage from sunlight. Albinism should be distinguished from extreme white spotting (when white spots cover the entire surface of the coat). Some cats with a pigmentation disorder called pieboldism (white spots or black and white blotches) or with a dominant white gene are prone to abnormalities in the nervous system, as well as deafness in one or both ears. About 75% of white cats with both blue eyes are deaf. Areas of the skin of cats with a lack of pigment or white with piebaldism are badly affected by exposure to the sun, in such cats, due to the sun, it is even possible to develop skin cancer, especially if the cat is short-haired and in areas with thin hair (like on the ears).

Lentigo. Lentigo is a pigment spots that form on the skin of cats. Usually observed in red (or with red spots on the face) cats. The first spots appear on the lips and eyelids at the age of about one year. Later, additional pigment spots form on the nose and lips. Lentigo spots are not precancerous and have no medical implications.

Vitiligo. Vitiligo is manifested in the disappearance of pigmentation in certain areas of the cat's skin. Although vitiligo is not noticeable at birth, this disorder is inherited by cats. Visible vitiligo usually becomes a "youthful" age. Affected cats develop discolored patches on their skin, sometimes the coat and nails can also discolor in these patches. Most of these spots are on the face, especially the bridge of the nose and around the eyes. The discolored areas may gradually become cloudy and decrease, although their complete disappearance rarely occurs. Vitiligo does not cause health problems. Treatments for vitiligo in humans are not suitable for cats, and there is no suitable treatment for vitiligo in cats.

Defects in the structural integrity of the skin in cats.

Some skin diseases are based on genetic defects that disrupt the structural integrity of the cat's skin.

Cutaneous asthenia(Cutaneous asthenia, also known as dermatosparaxis or Ehlers-Danlos syndrome) is a group of diseases characterized by impaired collagen production. Affected cats have very flabby, unusually stretchy and brittle skin, with loose joints and other connective tissue dysfunctions. These disorders are most common in Himalayan cats and domestic shorthair cats. For Himalayan cats, the disease is genetically recessive. In some lines of domestic shorthairs, disease genes are dominant.

Signs of cutaneous asthenia include fragility of the skin (from birth), poor resistance to damage that does not heal well with thin scars, sagging skin, hematomas (blood clots), and fluid-filled tumors or cysts (hygroms).

Diagnosis is made by a combination of signs, measurements of skin elasticity and laboratory analysis of the collagen structure of cat skin samples. In the initial diagnosis of cutaneous asthenia, veterinarians try to exclude other diseases (not hereditary) that could cause skin fragility. Typically, cutaneous asthenia is not life-threatening for the cat, although older animals develop hanging skin folds and extensive scarring is often present on the skin.

Epidermolysis bullosa(Epidermolysis bullosa syndromes) - a group of congenital hereditary defects in the area between the dermis and the epidermis of the skin. Minor skin trauma leads to the separation of the dermal and epidermal layers of the skin and the formation of blisters, which soon burst, forming shiny, flat ulcers. Skin lesions can be observed from the birth of a kitten, in the first week of life. The most severe injuries are usually found on the paws, face, mouth and genitals. In most cases, the manifestations of this disease are fatal.

Epidermolysis bullosa is most commonly seen in Siamese, shorthair domestic and Persian cats.

Multisystemic skin diseases in cats.

porfiria(or porphyrin disease) is a congenital disorder in the synthesis of hemoglobin and its offal in the blood of a cat. Symptoms of this disease in cats are:

• Photodermatitis (allergy to the sun) - inflammation of the skin after exposure to sunlight;
• Reddish-brown tint to teeth, bones, and urine;
• growth retardation;

Abnormal photophobia, characteristic of this disease in other animals, is not observed in cats. Laboratory tests of the urine are usually done to confirm porphyria, sometimes biopsies of skin samples are also used.

Congenital and hereditary skin tumors in cats.

Abnormal growth and spread of mast cells in the skin (benign hereditary cutaneous mastocytosis) is most common in young Siamese cats. This is a rare congenital disease in which the skin thickens and takes on a tree bark-like appearance. The disease is accompanied by intense itching. Treatment includes drugs to relieve itching and prevent the cat from causing damage to the skin.