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Alopecia |
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Simply put, alopecia is the loss or absence of hair. The hair loss may be localized or may be complete.
Causes are wide ranging including, but not limited to:
- Genetic
- Endocrine problems (such as hypothyroidism,
alopecia X and Cushing's Disease)
- Nutrition (iodine or selenium deficiency)
- Parasites or bacteria
- Immune-mediated disorders (like Lupus erythematosus)
- Stress
- Corticosteroids
Samoyeds as a
breed are at an increased risk for post-clipping alopecia, alopecia X
and sebaceous adenitis.
| Post-clipping alopecia is a common condition found primarily in sled dogs (Samoyeds, Siberian Huskies and Alaskan Malamutes), Keeshonds and Chow Chows. After the hair is shaved closely, like when shaving the hair for venapuncture, surgery or wound management, regrowth is delayed for up to 6 to 12 months. Two theories are proposed as to why this occurs in sled dogs: |
- The hair no longer insulates the skin and the blood vessels constrict causing loss of blood flow to the hair follicles. This may be an adaptive mechanism to reduce the loss of heat from the exposed skin area in harshly cold climates.
- Loss of the hair may cause a drop in temperature in the area that adversely affects the blood supply to the area.
Hair that eventually grows back in may be darker in color.
References:
- Mordecai Siegal (Ed.) The UC Davis Book of Dogs. 1995, HarperCollins Publishers.
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| Alopecia X is a catch-all phrase
that has been used at times to describe the following
conditions: |
- pseudo-Cushing
- adult-onset growth hormone deficiency
- growth hormone-responsive alopecia
- hyposomatotropism of the adult dog
- sex-hormone alopecia
- castration-responsive dermatosis
- gonadal sex hormone dermatoses
- sex hormone/growth hormone dermatosis
- follicular dysplasia of Nordic breeds
- Siberian Husky follicular dysplasia
- follicular growth dysfuntion of the
plush coated breeds
- adrenal sex hormone imbalance
- biopsy-responsive alopecia
- congentital adrenal hyperplasia-like
syndrome
- Lysodren-responsive dermatosis
The breeds most affected
by alopecia X are Pomeranians, Chow Chows, Miniature Poodles,
Siberian Huskies, Keeshunds and Samoyeds.
Signs and Symptoms
- adult onset (typically
9 months to 3 yrs) symmetrical alopecia which progresses to
involve the neck, back, hindlegs, chest, rump
and tail
- may or may not have
hyperpigmentation in affected areas
- hair on head, tail and
feet are usually not affected
- affects dogs more than
bitches
- may occur before or
after neutering
- coat is dry and dull
- loss of guard coat
- hair may regrow at
site of biospy
Similar Diseases that must be ruled out:
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hypothyroidism
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Cushing's Disease (hyperadrenocorticism)
- hyposomatotrophism
- gonadal sex hormone imbalance
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seasonal flank alopecia
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post clipping alopecia
-
follicular dysplasia
Diagnosis:
- do multiple skin biopsies from affected and adjacent areas
for histological examination
- ACTH response test with measurement of sex hormones and
precursors: key finding --> progesterone
level triples after ACTH response test (the University of Tennessee College
of Veterinary Medicine
Endocrinology
lab can perform these tests)
Treatment (some of these are
experimental and potentially toxic):
- neutering of male dogs
- methyltestosterone
- low dose lysodren
- melatonin
References:
- Cerundolo R, Lloyd D.'Alopecia X' in chows, pomeranians and
samoyeds. Vet Rec 1998 Aug 8;143(6):176.
- Kirk's Current Veterinary Therapy XIII-Small Animal
Practice, "Melatonin Therapy for Canine Alopecia" by Manon Paradis,
DVM, MVSc, Dipl. ACVD, pages 546-549.
- Pat White, DVM, Ms, Dipl. ACVD, "Identifying
'look-alike' endocrine diseases.", DVM Newsmagazine Best Practices,
June, 2001, pp. 17-22.
More info HERE
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| Hot Spots |
| With a couble-coated breed such as the Samoyed, hot spots can be a real problem. Keeping the coat clean and dry with frequent brushing to remove mats of hair can prevent hot spots from forming. Leaving the coat even slightly damp after a bath can provide a moist warm environment for fungus and bacteria to proliferate. Visit The Pet Center.com,
Hot Spots! Just What Are These, Anyway? by Dr. T. J Dunn, for pictures and hot spot treatments.
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| Lick Granuloma (Acral Lick Dermatitis) |
| Chronic licking in the same area that finally results in the loss of hair and a thickening of the skin in the area. Adult dogs, over 3 years of age, are the most affected. An excellent description of the causes of lick granulomas, with pictures, is available at The Pet Center.com,
Lick Granulomas... A Dermatology Nightmare by Dr. T. J Dunn.
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| Sebaceous Adenitis (SA) |
| An inflammatory disease of sebaceous (sweat) skin glands that eventually leads to loss of the hair follicle. It affects young to middle aged Samoyeds. The disease may be inherited or immune mediated. SA has not been studied in the Samoyed, but in other breeds, it has been found to be a simple autosomal recessive. |
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| Signs and Symptoms |
- Symmetrical, partial hair loss, usually patchy
- Dull brittle coat
- Scaly skin
- Lesions often appear first along the top line
Definitive
Diagnosis
- SA mimics other diseases, including hypothyroidism and skin allergies. Therefore, it is necessary to have a skin biopsy performed which can be interpreted by a veterinary pathologist.
Treatment
Various home treatments have been tried, with mixed results. The following links have some helpful suggestions.
Reference:
- Tilley, LP, Smith, FWK, The 5 Minute Veterinary Consult, Canine and Feline. 1997, Williams & Wilkins.
Suggested SA Links:
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