Heather, below is a
general outline of the disease,
Hope it's helpful....... If you type in the name you will get
dozen's of sites about it.
Kay
related terms: colour mutant
alopecia, blue or fawn Doberman syndrome, fawn Irish setter syndrome,
blue dog disease
What is colour
dilution alopecia?
This condition develops in some, but not all
dogs that have been bred for unusual coat colour, especially "fawn" (a
dilution of a normally red or brown coat) or "blue" ( a dilution of
the normal black and tan coat colour). Alopecia means hairlessness -
affected dogs have a poor, patchy haircoat progressing to widespread
permanent hair loss. At the cellular level, there are abnormalities of
the hair follicles and uneven clumping of pigment (melanin) granules in
the hair shafts in affected areas
How is colour dilution alopecia
inherited?
The inheritance is unclear. The condition is
thought to be due to the interaction of different factors at the gene
position for colour. It is not simply determined by the genes at that
locus, because not all dogs with colour dilution develop coat problems.
What breeds are
affected by colour dilution alopecia?
This condition is seen most commonly in
Doberman pinschers with unusual coat colours (as many as 90% of blue
Dobermans and 75% of fawns). The condition also occurs but is less
common in other breeds bred for unusual coat colours: Bernese mountain
dog, chihuahua (blue), chow chow (blue), dachshund (blue), Great Dane
(blue), Irish setter (fawn), miniature pinscher (blue), saluki,
schipperke (blue), Shetland sheepdog (blue), standard poodle (blue),
whippet (blue), Yorkshire terrier (grey-blue).
For many breeds and many
disorders, the studies to determine the mode of inheritance or the
frequency in the breed have not been carried out, or are inconclusive.
We have listed breeds for which there is a consensus among those
investigating in this field and among veterinary practitioners, that
the condition is significant in this breed.
What does colour dilution alopecia mean
to your dog & you?
Dogs with this condition are born with a normal
haircoat. Those with lighter blue or fawn hair coats usually start to
show changes by 6 months while in dogs with darker steel blue coats,
the changes may not be evident until 2 or 3 years of age. Your dog will
experience hair loss and dry skin. Sometimes the earliest sign is a
recurring bacterial infection (folliculitis), generally on the back,
where you will see small bumps which are infected hair follicles. This
clears up temporarily with antibiotics, but the affected area is very
slow to regrow hair, or remains hairless.
Hair loss is usually first apparent on the back
and by 2 or 3 years has spread over all the light coloured areas of the
body. The exposed skin is often scaly and is susceptible to sunburn or
extreme cold. Your dog's health is not otherwise affected by this
condition.
How is colour dilution alopecia
diagnosed?
Your veterinarian may suspect this disorder if
your dog has typical haircoat changes and is an unusual colour for the
breed. The diagnosis is confirmed through microscopic examination of
plucked hairs or a skin biopsy. The latter is a simple procedure, done
with local anesthetic, in which your veterinarian removes a small
sample of your dog's skin for examination by a veterinary pathologist.
The biopsy will show changes characteristic of this condition.
For the veterinarian: Careful
microscopic examination of plucked hairs will show large clumps of
melanin distributed unevenly along the hair shaft.
In young dogs, demodicosis or other inherited
hair defects should be considered while in dogs with a later onset (2
to 3 years of age), endocrine disorders (particularly hypothyroidism)
should be ruled out.
How is colour dilution alopecia treated?
Your dog can lead a normal healthy life with
periodic symptomatic treatment as needed - moisturizing rinses for dry
scaly skin or antibiotics for bacterial infections.
Since early hair loss occurs due to breakage,
you may be able to slow the rate of loss by avoiding harsh shampoos and
vigorous grooming.
For the veterinarian: There
have been some early reports of hair regrowth using etretinate
treatment . (See resource below.)
Breeding advice
Affected dogs, their parents and siblings
should not be used for breeding. The condition can be entirely avoided
by the use of non-colour-diluted dogs in breeding programmes.
FOR MORE INFORMATION ABOUT THIS
DISORDER, PLEASE SEE YOUR VETERINARIAN.
Resources
Scott, D.W., Miller, W.H., Griffin, C.E. 1995.
Muller and Kirk's Small Animal Dermatology. p. 777. W.B. Saunders Co.,
Toronto.
Power, H.T., Ihrke, P.J. 1995. The use of
synthetic retinoids in veterinary medicine. In S.J. Ettinger
and E.C. Feldman (eds.) Textbook of Veterinary Internal Medicine. p
585-590. W.B. Saunders Co., Toronto.
