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Exfoliative Dermatoses in Dogs

Exfoliative dermatoses refers to a group of skin disorders that can be traced to one or more underlying disorders, which share the common symptom of scaling skin, but may vary in severity and treatment methods. Therefore, exfoliative dermatoses is not the primary diagnosis, but the main descriptor. It is typically due to excessive or abnormal shedding, excessive accumulation of skin cells, or a loss of the cells' ability to adhere to each other.

This condition can affect dogs of any breed or age, but there are some breeds that are reported to be more prone to it. Cocker spaniels, West Highland white terriers, English springer spaniels, basset hounds, Irish setters, Doberman pinschers, Labrador retrievers, Alaskan malamutes, Siberian huskies, chow chows, poodles, Yorkshire terriers, whippets, Great Danes, salukis, Italian greyhounds, standard poodles, Akitas, Samoyeds, and golden retrievers.

If your dog is pregnant, you will need to make your veterinarian aware immediately, as some medications for the skin can have an impact on the developing fetus.

Symptoms and Types

• Scales may be seen as fine particles, such as dandruff, or in sheets (coarse scale)
• Greasy or dry accumulation of surface skin cells, as seen in dandruff
• Excessive scaling due to shedding of skin cells
• Itchiness
• Accumulations may be found throughout the hair coat or in certain localized areas
• Filling of hair follicles with oil and skin cells
• Accumulation of debris around the hair shaft
• Excess scales and crust on the nasal planum and footpad margins – may lead to cracking of skin and bacterial invasion
• Hair loss (alopecia)
• Skin infections characterized by presence of pus
• Rancid fat odor
• Nails may also be affected

Causes

• In some cases the exact cause remains unknown (idiopathic seborrhea)
• Vitamin A deficiency in some cases (cocker spaniels)
• Zinc deficiency in some cases (Alaskan malamute, Siberian husky, large breed puppies)
• Abnormal skin and hair follicle development
• Thickening of skin due to unknown cause
• Inflammation of sebaceous glands (glands that produce oils in the hair coat)
• Congenital defects in normal replacement of shedding of skin cells
• Allergy (pollen allergy, flea bite allergy, food allergy etc.)
• Parasitic infestation (cheyletiellosis, demodicosis, mange)
• Skin infections
• Hormonal disorders
• Age related (seen in older dogs due to natural alterations associated with aging)
• Nutritional disorders and reactions (malnutrition, feeding generic food)
• Diseases of immune system, where the body’s immune system attacks its own skin (pemphigus)
• Diabetes melitus
• Tumors of the skin

Diagnosis

You will need to give a detailed history of your dog’s health, and the onset and nature of the symptoms. In order to find the underlying cause for the skin disorder, your veterinarian will perform several tests. Because there are so many possible causes for this condition, your veterinarian will most likely use differential diagnosis. This process is guided by deeper inspection of the apparent outward symptoms, ruling out each of the more common causes until the correct disorder is settled upon and can be treated appropriately.

Standard tests will include a complete blood count, biochemistry profile, and urinalysis, which are often within normal range unless there is a concurrent disease that is associated with the blood, such as hyperthyroidism, bacterial infection, fungal infection, or cancer.

To evaluate the skin, the following procedures may be required:

• Skin scrapings, which will be sent to lab for fungal, bacterial cultures
• Skin biopsy
• Skin allergy – intradermal skin testing
• Testing for ectoparasites (skin parasites)
• Food elimination trial may be used if a food ingredient is suspected