Dermatoses, Depigmenting Disorders
Skin infections and disorders causing loss of skin color are common issues in various dog breeds. Dermatoses, which refer to skin diseases, encompass bacterial infections and genetic conditions affecting the skin. While some dermatoses are primarily cosmetic, causing loss of pigmentation in the skin and hair coat, they are generally not harmful.
German Shepherds are prone to bacterial skin infections affecting the lips, eyelids, and nostrils. Additionally, German Shepherds, Collies, and Shetland Sheepdogs have a predisposition to lupus, an autoimmune disorder where the body mistakenly attacks its own skin and organs. Specifically, they may develop discoid lupus, a form of lupus that affects only the skin, typically on the face.
Chow Chows and Akitas are susceptible to an autoimmune skin disease characterized by inflammation, crusting, and pus-filled lesions. A rare syndrome affecting Akitas, Samoyeds, and Siberian Huskies leads to inflammation in the front part of the eye, particularly the iris, accompanied by pigment loss in the skin of the nose and lips.
Doberman Pinschers and Rottweilers may experience a condition marked by symmetrical loss of skin pigmentation and a white hair coat, predominantly on the face and nose. Seasonal loss of pigment in the nose’s tough, hairless skin can occur in Siberian Huskies, Alaskan Malamutes, and Labrador Retrievers. St. Bernards and Giant Schnauzers may suffer from arterial inflammation in the nasal philtrum, the area between the sides of the upper lip extending to the nose.
Symptoms and Types
- White hair, medically termed as leukotrichia
- Partial or complete absence of pigment in the skin, referred to as leukoderma
- Skin reddening, known as erythema
- Loss of the skin’s top layer, termed as erosion or ulceration, depending on the depth of tissue loss
Causes
- Bacterial skin infections, with commonly affected areas including:
- Lips
- Eyelids
- Nostrils
- Fungal skin infections
- Contact hypersensitivity (allergies)
- Predominant impact on facial skin
- Redness and pus on the face and ears
- Presence of crusting scabs and pus on the skin
- Loss of skin and hair color following skin inflammation
- Loss of color on the nose and lips, accompanied by vision impairment
- Seasonal depigmentation of the nose
- Inflammation of the arteries in the nasal philtrum (front of the nose, above the upper lip)
- Albinism (genetic)
- Vitiligo (smooth white patches on the skin due to loss of pigment)
- Severe cases involving skin and internal organs
- Autoimmune diseases, often linked to genetic predisposition, including:
- Systemic lupus erythematosus
- Discoid lupus erythematosus
- Pemphigus foliaceus
- Pemphigus erythematosus
- Uveodermatologic syndrome
- Hormonal disorders
- Reactions to medications
Diagnosis
Upon observing your dog’s condition, the veterinarian will conduct a comprehensive physical examination, considering the history of symptoms and potential triggering incidents, such as recent infections. Providing a detailed health history and outlining the onset of symptoms will be essential. To gather more information, your veterinarian will order various tests, including a blood chemical profile, a complete blood count, an electrolyte panel, and a urinalysis. Blood samples may also be assessed for autoimmune factors.
As part of the physical examination, skin samples and scrapings will be collected and sent to a laboratory for bacterial and fungal cultures. If a skin biopsy reveals the separation of skin cells (acantholysis), it serves as a diagnostic indicator for pemphigus. Direct immunofluorescence of skin samples, using fluorescent dyes, can be employed to highlight antibodies. Additionally, fluid samples may be taken from your dog’s joints to investigate the presence of lupus. These diagnostic measures contribute to a comprehensive understanding of your dog’s condition.
Treatment
Unless lupus has led to multiple organ dysfunction, outpatient treatment is typically suitable for your dog. If a bacterial or fungal infection is diagnosed, your veterinarian will prescribe antibiotics. Immunosuppressive medication is commonly administered for autoimmune disorders. In cases where your dog’s eyes are affected, your veterinarian may recommend consulting a veterinary ophthalmologist. It’s important to refrain from using any topical medications or ointments unless specifically prescribed by your veterinarian for your pet’s condition.
Living and Management
For dogs diagnosed with systemic lupus erythematosus, discoid lupus erythematosus, or pemphigus erythematosus, it’s crucial to shield them from sun exposure. Apply water-resistant sunscreen with an SPF greater than 30 to depigmented areas of your dog’s skin before outdoor activities. Replace plastic or rubber dishes, especially if they have rough edges that could cause abrasions.
If your dog’s skin condition deteriorates, promptly contact your veterinarian, as it may indicate underlying issues such as a spreading infection. Your veterinarian will schedule follow-up appointments as needed to monitor your dog’s skin condition. Animals receiving immunosuppressive medications for autoimmune diseases should undergo frequent blood tests for monitoring purposes.