Abnormal Skin Formation in Dogs

Keratinization is generally divided into primary and secondary disease. Primary keratinization is usually seen within the first year of life, and can be caused by genetics and nutritional deficiencies. Primary idiopathic seborrhea refers to a condition of keratinization that cannot be explained by a known cause.

Most cases of abnormal skin formations fall under secondary keratinization, which can be caused by infections, allergies, and internal conditions such as cancer, and endocrine, autoimmune and skin disease.

Abnormal formations of skin are generally due to a disruption in normal skin growth. When the cells behave abnormally due to this disruption, keratinization occurs that causes changes in the skin and hair. Crusting and scaling skin can be accompanied by itching, hair loss, and ulcers as the skin tears open and becomes infected.

Abnormal skin formations can affect the skin, hair follicles, and even the claws. Commonly affected areas include the eyes, ears, mouth, nose, elbows, genitals, and anal areas. Less common areas can include the armpits, footpads, and on the back. Symptoms of keratinization include:

• Reddened and inflamed skin
• Itchy skin
• Scaly skin that can be mild to severe, affecting large patches of skin
• Crusty skin 
• Thickened or leathery skin
• Skin ulcers
• Greasy or smelly skin patches
• Blisters and pustules that can rupture 
• Acne 
• Skin tumors or other growths 
• Darkened patches of skin
• Dry or greasy hair coat
• Brittle hair strands
• Hair loss
• Dandruff
• Brittle or rough claws that can break easily

Types

Due to the highly genetic nature of primary keratinization, there are many types that have been classified. Types of primary keratinization include:

• Color dilution alopecia
• Follicular dystrophy 
• Ichthyosis, commonly affecting Terriers breeds, Golden Retrievers, Doberman Pinschers, and Cavalier King Charles Spaniels 
• Sebaceous adenitis, commonly affecting Akitas, Hungarian Vizslas, Standard Poodles, and Samoyeds 
• Lichenoid psoriasiform dermatosis 
• Schnauzer comedo syndrome
• Epidermal dysplasia 
• Hereditary nasal parakeratosis, affecting Labrador Retrievers
• Acne
• Nasodigital hyperkeratosis
• Zinc responsive dermatosis, commonly affecting Alaskan Malamutes, Samoyeds, and Siberian Huskies 
• Vitamin A responsive dermatosis, affecting American Cocker Spaniels
• Fatty acid deficiency

The normal process of skin growth can be disrupted, causing the abnormal skin growth seen in keratinization. Reasons why the skin cells may grow abnormally include:

• Genetic defect
• Vitamin deficiency
• Parasitic infection, such as Sarcoptes, Demodex, or Cheyletiella
• Bacterial infection
• Fungal infection, such as ringworm 
• Allergic response, including to food, fleas, and contact allergies
• Auto-immune disease, such as the pemphigus complex or systemic lupus erythematosus
• Endocrine disorder, such as hypothyroidism or Cushing’s disease
• Cancer, such as lymphoma

In order to discover a cause, your veterinarian will examine your dog’s abnormal skin areas during a physical exam. Relay to the vet any other kinds of symptoms you may have seen in your dog, as these can help point to the reason behind the keratinization. Factors such as the age and breed of your dog can narrow down possible diagnoses, as can any recent exposures to allergens, infections or parasites. Your vet may also inquire about your dog’s diet.

A urinalysis and blood testing can reveal the presence of infectious agents, as well as measure blood glucose levels, cholesterol, and other chemicals. Scrapings, smears, and cultures taken from skin samples can verify the presence of any types of infections and diseases. A skin biopsy may be performed, which can help to diagnosis many types of infections, cancers, and autoimmune diseases. If you have noticed a growth on your dog, monitoring and taking notes on its appearance and size can help in determining whether it is malignant or benign, as well as point to a possible cause. 

A diagnosis is generally made based on the physical appearance of the abnormal skin and the results of testing. A diagnosis of an idiopathic keratinization disorder can be made after other conditions are ruled out.

Once the cause for the keratinization has been diagnosed, therapy attempts to treat the underlying cause while treating the skin. 

A vitamin deficiency can be treated with vitamin supplementation, with results seen in up to three months. Infections are treated with oral or topical medications to control the fungus, parasites or bacteria. A medicated dip can also be prescribed to kill off infectious agents on the skin. Any allergies that may be the cause need to be identified. Diets may need to be changed to eliminate the food allergen, flea treatments can reduce exposure to flea bites, antihistamines can help to stop the allergic response, and immunotherapy can arm the immune system to fight the allergen. 

Auto-immune diseases are treated with immunosuppressive drugs, along with antibiotics and medicated baths if a bacterial infection is also present. Hormonal imbalances resulting from endocrine malfunctions can be treated with medications, and sometimes, surgical removal of any adrenal tumors. Growths that are cancerous are generally removed. Other cancer therapies can include immunotherapy, chemotherapy, and radiation. 

To treat and soothe the skin, topical shampoos, creams and lotions are prescribed. They may contain omega-3 and omega-6 fatty acids, antiparasitics or antifungals, ethyl lactate, tar, sulfur, salicylic acid, emollients, or other ingredients. These topical treatments can control infections, moisturize the skin, decrease oily secretions, normalize the skin cell turnover rate, remove dead skin cells, and reduce skin scaling, all of which promote normalized skin growth.

The recovery of abnormal skin formations in your dog will depend on the reason behind the abnormal growth. Primary keratinization that is genetic cannot be cured, but can be successfully managed with consistent bathing in specialized shampoos. Many other infections and conditions can be successfully treated. Severe internal conditions, such as cancer and autoimmune disease, may carry guarded prognoses, depending on your dog’s particular condition. 

Prevention of infections can occur through limiting or eliminating your dog’s exposure to infectious agents. Keep your dog away from sick animals, and quarantine any new animals until cleared with a clean bill of health. Dogs who have hereditary primary keratinization should not be bred.