What are some of the causes of Dry or Flaky Skin on Dogs?
Sometimes it is as simple as just dry skin on your dog, but other times the causes can be quite serious. There are many different causes of dry skin. It's a long list and can be difficult to diagnose.
Here is a list of different causes for dry skin:
Black Hair Follicular Dysplasia/Alopecia/Dystrophy
This is a rare hereditary disease in dogs with different hair colors. It's more common in Bearded Collies, Basset Hounds, Salukis, Beagles, Dachshunds, and Pointers. The Symptoms are loss of dark or black hair only. The symptoms appear between 3 and 6 weeks of age and sometimes causes scaling. The diagnosis is clinical signs and biopsy. Treatment includes shampoos for scaling.
Canine Distemper (Hard Pad Disease)
With vaccinations, canine distemper has become rare in many areas, foot pad lesions are common in this disease. Symptoms: Puppies may develop impetigo; thickening of the end of the nose and foot pads; also see other signs of illness associated with distemper. Diagnosis: History of no vaccination, physical exam, blood tests to detect antibody response to viral infection. Treatment: Supportive treatment; may be fatal or result in permanent problems.
Castration Responsive Dermatosis
More common in young unneutered dogs, and in Chows, Samoyeds, Keeshonden, Alaskan Malamutes, Miniature Poodles, and Pomeranians. Symptoms: Symmetrical hair loss in genital area and neck; hair loss may progress onto trunk; skin may appear darker; sever scaling; hair color may fade; coat is similar to a puppy coat. Diagnosis: Physical exam and history; eliminate other causes; blood tests for hormone levels. Treatment: Castration
Cheyletiella (Rabbit Fur Mite) mange
Infection with the Cheyletiella mite Symptoms: Itching, Scaliness; some hair loss, if sever. Skin scrapping and microscopic examination the mite is often very difficult to find. Treatment: Pyrethrin, Permethrin
Cushing's Disease (Hyperadrenocorticism)
Caused by an increase in corticosteroids in the body, either due to increased production by the body or as a side effect of high doses or prolonged therapy with corticosteroids. Symptoms: Hair loss, thinning of skin, hyper pigmentation, easy bruising, seborrhea, comedones (black heads), may see calcinosis cutis; lethargy, increased thirst and urination, pot-bellied appearance. Diagnosis: Adrenal gland function tests, urinalysis, chemistry panel, CBC Treatment: If due to glandular tumors, selegiline, o,p-DDD (Mitotane) or surgical removal of tumor; if due to high steroid doses, withdrawl use of steroids slowly.
Demodectic mange (Red mange, Puppy mange)
Infection with the Demodex mite occurs when the immune system is deficient. Symptoms: Hair loss, Scaliness, redness, pustules, ulcers, sometimes itching, darkening of skin. Diagnosis: Skin Scraping and microscopic examination Treatment: No Steroids!! Amitraz (Mitaban) dips
Dermatomyositis
Some breeds predisposed; cause unknown; aggravated by trauma and UV light. Symptoms: Redness, scaling, crusting, hair loss, and scarring on face, ears, and tail; atrophy of muscles involved in chewing. Diagnosis: Skin biopsy Treatment: Minimize trauma and exposure to UV light; Vitamin E, fatty acids, short term use of prednisone, oxpentoxifylline; some severe cases do not respond to treatment, and euthanasia may be considered.
Epitheliotrophic Lymphoma (Mycosis Fungoides)
Rare cancer of T lymphocytes seen in older dogs. Symptoms: Can take multiple forms; redness with itching and scales; ulcers and loss of pigment; one or more nodules; oral ulcers Diagnosis: Needle or other biopsy Treatment: Poor response to treatments. which include chemotherapy, surgical removal, retinoids, fatty acids.
Flea Allergy Dermatitis (Flea Bite Hypersensitivity)
Severe reaction by the animal to the saliva of the flea. Symptoms: Intense itching, redness, hair loss, papules, crusts, and scales; sometimes development of infection or hot spots. Diagnosis: Presence of fleas; reaction to intradermal testing Treatment: Flea Control in the environment and on the dog; steroids and antihistamines for the itching.
Hypothyroidism
Decreased production of thyroid hormones; most common hormonal disease affecting the skin in dogs. Symptoms: Hair loss, dry and brittle hair, seborrhea; secondary bacterial and yeast infections; lethargy, obesity, slow heart rate; changes in skin pigmentation may occur. Diagnosis: Thyroid gland function tests, chemistry panel, CBC. Treatment: Lifetime thyroid supplementation.
Lchthyosis (Fish Scale Disease)
Very rare. Symptoms: Excessive thickening and crusting of skin and foot pads; seborrhea; odor; symptoms start in puppies. Diagnosis: Biopsy Treatment: Difficult to treat; intense, lifetime management required, treat seborrhea, retinoids
Impetigo (Bacterial Infection or Pyoderma)
Usually affects puppies less than one year of age; often a Staph infection. Symptoms: Localized area of small pustules especially on the abdomen, crusts, curcular areas of scaling. Diagnosis: History and physical exam; bacterial culture; skin scraping. Treatment: Topical hydrogen peroxide; chlorhexidine, or benzoyl peroixide shampoos; anibiotics, if serious; puppies usually outgrow it. Note: The above treatments sometimes makes it worse and doesn't always clear it up.
Leishmaniasis
Caused by a parasite of blood cells; can be transmitted to people who develop a very severe disease. Symptoms: Hair loss, scaling, ulcers on nose and ears, sometimes nodules; many other non-skin related signs. Diagnosis: Identify the organism in blood or biopsy; blood tests Treatment: Because it causes severe disease in people, and treatment of dogs is not curative, euthanasia may be performed.
Lupus Erythematosus
Caused by a parasite of blood cells; can be transmitted to people who develop a very severe disease Symptoms: Skin lesions may include thickening or ulcers of the foot pads, scaling, and recurring bacterial infections with pustules. Diagnosis: Special blood tests (LE test); biopsy Treatment: Prednisone and other immunosuppressive drugs; treat underlying infections.
Malassezia
Usually follows some other underlying disease. Symptoms: Itching, redness, hair loss, greasy scales; if chronic, develop hyperpigmentation Diagnosis: Skin scraping/smear and microscopic examination culture Treatment: Treat underlying disease; oral ketoconazole; miconazole shampoos
Nasodigital Hyperkeratosis
Thickening of nose and footpads may be due to underlying diseases such as lupus, distemper, or zinc responsive dermatosis; in other cases cause unknown Symptoms: End of nose becomes thickened dry and rough; foot pads thicken and crack making it painful to walk. Diagnosis: History, physical exam, biopsy, look for underlying diease Treatments: Treat any underlying diease; remove excess thickening, soak areas and apply Retin-A
Pelodera Dermatitis
Accidental infection with larvae from a non-parasitic worm that lives in straw and other organic material. Symptoms: Affects areas of the skin touching the ground; intense itching, redness, hair loss, papules, crusts, and scales. Diagnosis: Skin scraping and microscopic examination Treatment: Remove bedding; mild antibacterial shampoo; steroids if necessary to control itching
Pituitary Dwarfism
Hereditary condition in which the pituitary gland does not produce the necessary hormones. Symptoms: Young puppies fail to grow; dogs retain puppy coat and condition progresses to hair loss over much of the body; thin skin, scales and secondary infections Diagnosis: Special blood testing for the presence of certain hormones. Treatment: Hormone replacement therapy
Ringworm
Infection with several types of fungus. Symptoms: Hair loss, scaliness, crusty areas, pustules, vesicles, some itching; can develop a draining nodule called a "kerion" Diagnosis: Culture Treatment: Miconazole, lime sulfur dips; oral griseofulvin or itraconazole
Sarcoptic Mange
Infection with the Saracoptic mite Symptoms: Intense itching and self-trauma, hair loss, papules, crusts, and scales Diagnosis: Skin Scraping and microscopic examination - the mite is often very difficult to find Treatment: Amitraz (mitaban) dips; ivermectin
Sebaceous Adenitis
Sebaceous glands are destroyed, cause unknown; certain breeds more susceptible Symptoms: Short-haired breeds; Circular areas of hair loss with fine scale; Long-haired breeds: More widespread hair loss and scale, hair mats easily; may see itching in all breeds Diagnosis: Clinical signs, breed, skin, biopsy Treatment: Antiseborrheic shampoos, fatty acid supplements; in more severe cases, steroids, retinoids
Seborrhea
Can be primary (inherited) or secondary (resulting from other disease processes such as allergies, hypothyroidism) Symptoms: Scales; depending upon the type, may have a dry or oily coat; odor; some scratching; may see hair loss Diagnosis: Blood tests, skin scrapings, etc., to find underlying cause Treatment: Treat underlying cause if present; antiseborrheic shampoos; fatty acid suppliments
Solar Dermatosis
Skin reaction to sunlight, especially unpigmented skin; most common on noses of Collies, Shelties, and similar breeds Symptoms: Redness, hair loss, and scaling on nose and ears, later crusts and ulcers Diagnosis: History, Breed, physical exam, skin biopsy Treatment: Must avoid further sun exposure, especially 9am-3pm; sunblock; steroids; tattoo nose or apply black ink
Testosterone Responsive Dermatosis (hypoandrogenism)
More common in old neutered dogs, and in Afghans. Symptoms: Dull, scaly, dry coat, seborrhea; hair loss in genital and anal areas progressing onto trunk Diagnosis: Physical exam and history; eliminate other causes; response to therapy Treatment: Testosterone replacement therapy
Vitamin A Responsive Dermatosis
May not be due to an actual deficiency of Vitamin A, but does respond to increased levels of Vitamin A in the diet; more common in Cocker Spaniels Symptoms: Seborrhea, odor, hair pulls out easily; pads of feet thickened; thick scales on chest and abdomen, especially around nipples Diagnosis: Clinical Signs, breed, skin biopsy Treatment: Lifetime treatment with Vitamin A
Zinc Responsive Dermatosis
Three types: 1. in Huskies and Malamutes; 2. in rapidly growing puppies of large breeds; 3. in English Bull Terriers Symptoms: Crusting and scaling; redmess, hair loss, sometimes oily skin, secondary backterial infections common Diagnosis: History, breed, physical exam, skin biopsy Treatment: Correct any dietary deficiency, medicated shampoos, treat secondary infections.
References and Further Reading:
Birchard, SJ: Sherding RG (eds.) Saunders Manual of Small Animal Practice. W.B. Saunders Co. Philadephia, PA 1994. Greene, CE (ed.) Infectious Diseases of the Dog and Cat W.B. Saunders Co. Philadelphia, PA 1998