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CANINE SEBORRHEA
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Seborrhoea is a group of
disorders affecting the keratin layers of the skin, leading to a greasy
or dry coat. The Dogs outer layers of skin, sebaceous glands and
hair follicles are over active causing the over-production of sebum
(fatty lubricating substance) and skin cells. Primary seborrhea occurs
in dogs under the age of 18 months. It is a chronic condition
which
leaves the skin greasy, scaly and smelly and the ears have a waxy
buildup.
Seborrhea
Seborrhea1
Scratching the Surface of Canine Skin Disease
What is seborrhea?
Primary seborrhea is an inherited disorder of the skin in
which the outer layer of the skin (the epidermis), the sebaceous
glands,
and part of the hair follicles are hyperproductive. The rate of cell
turnover in these tissues is significantly increased, causing excessive
production of scale (dry flakes of skin) and sebum (fatty lubricating
substance). Seborrhea oleosa is the more greasy form while seborrhea
sicca
is a dryer form. Many dogs have a combination of both types. Chronic
waxy
ear infections (otitis externa) also occur commonly as part of this
disorder.
Signs of primary seborrhea are usually apparent by a year
of age. Affected dogs are often greasy, scaly and smelly.
Secondary seborrhea is seen in older dogs. It looks the same clinically
but is a response by the skin to other conditions, rather than an
inherent defect in the skin itself.
How is seborrhea inherited?
Primary seborrhea is probably inherited as an autosomal recessive trait
in the West Highland white terrier, and this may also be true in other
breeds. This means there can be affected puppies in a litter where both
parents have normal skin but carry the gene for seborrhea.
Autosomal dominant inheritance with variable expressivity may be the
mode of inheritance in some breeds.
What breeds are affected by seborrhea?
Primary seborrhea is most commonly seen in the American cocker spaniel,
West Highland white terrier, English springer spaniel, and Basset
hound. It is also seen in the Irish setter, German shepherd, dachshund,
Doberman pinscher, Chinese Shar-pei, and Labrador retriever.
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 seborrhea mean to your dog & you?
Early evidence of the disorder such as mild flaking and dullness of the
coat may appear as young as 10 weeks of age. Because these signs are
subtle, they often go unnoticed. However, usually by a year to 18
months, the signs have become pronounced. Affected dogs commonly have a
dull coat with excessive scaling, a greasy feel and smell to the skin
(especially in areas of body folds), smelly waxy ears which may be
infected, thickening of the foot pads, and dry brittle claws. Some
breeds (West
Highland white terrier, cocker spaniel, springer spaniel, Basset hound,
Shar-pei) are more prone to the greasy form of seborrhea (seborrhea
oleosa)
with chronic ear infections and greasy skin, while others (Doberman
pinscher, Irish setter) are more likely to develop the dryer form
(seborrhea sicca)
Dogs with seborrhea are prone to secondary infections, either bacterial
or yeast, and frequently develop skin lesions and associated itching.
This condition is called seborrheic dermatitis. Scratching
leads to worsening of the lesions and spread of the infection.
How is seborrhea diagnosed?
The signs associated with primary (inherited) and secondary (response
to another condition) seborrhea are the same. Your veterinarian will
take into consideration your dog's clinical signs and age (primary
seborrhea is seen in young dogs), and submit a skin biopsy to a
veterinary pathologist who will look for changes in the skin typical of
primary seborrhea, to rule-out other conditions that cause similar
clinical
signs. (This is a simple procedure, done with local anaesethetic, in
which your veterinarian removes a small sample of your dog's skin.)
When there is severe seborrheic dermatitis, the secondary
infections must be cleared up before a diagnosis of primary seborrhea
can be made.
For the veterinarian: Staphylococci and Malassezia
are opportunistic pathogens that are believed to play a significant
role in seborrheic dermatitis and otitis. Intense pruritis is common
where there is secondary infection with these organisms.
Besides primary seborrhea, rule-outs in young dogs (less than 12 to 18
months) with seborrheic signs include demodicosis, cheyletiellosis,
food hypersensitivity, epidermal dysplasia, nutritional deficiency,
and ichthyosis.
How is seborrhea treated?
Primary seborrhea requires life-long management. There is
no cure, and the ease of control varies between dogs. Dry scaly
seborrhea can usually be controlled more easily than the greasy form.
You and your veterinarian will need to work together to determine what
is best for your dog. You will quickly become an expert on recognizing
changes in
your dog's skin and ears, and knowing when veterinary care is
required.
Antiseborrheic shampoos and moisturizers are the most important
components of treatment. Initial bathing of 2 or 3 times per week
is generally required, with frequency gradually reduced to a
maintenance level as the condition is controlled. If your dog has a
secondary bacterial or yeast infection (as is common), this must be
treated with appropriate medication at the same time that
antiseborrheic therapy is started.
Effective bathing requires that the medicated shampoo remain in contact
with the skin for 10 to 15 minutes after lathering, followed by very
thorough rinsing which removes debris (scales, grease) and
shampoo, and also moisturizes your dog's skin. An after-bath rinse
will also help to retain moisture. Occasional misting of the coat with
the dilute rinse can often reduce the frequency of bathing required.
Careful monitoring is required, since over-bathing can worsen seborrhea.
There are a large number of antiseborrheic products available. Your
veterinarian will likely suggest a milder product to start, and change
to a stronger one if necessary. Stronger products are usually required
to control dogs with greasy skin, with possible switch to a milder
product for maintenance. Long hair makes effective shampooing more
difficult
so it is best to keep the coat short.
Ear infections are common in seborrheic dogs. The best way to keep on
top of these is to check your dog's ears regularly. Your veterinarian
will show you how to flush your dog's ears with a product designed
to reduce wax build-up. Use this when your dog's ears have a waxy
odour. Signs of an infection include a need to clean the ears
more frequently, itchiness (as shown by head shaking, pawing at the
ears, rubbing the
head along the carpet) and/or an unpleasant odour. This requires prompt
treatment, usually for 2 to 3 weeks.
It is important to watch carefully for any other conditions in your
dog, as the signs of seborrhea will worsen dramatically if
s/he develops nutritional inadequacies, external parasites (fleas for
example) or some other illnesses. A sudden worsening of seborrhea (a
need for more frequent bathing or an increase in odour) can also
indicate
a secondary skin infection to which these dogs are prone. Such
infections
should be brought under control quickly with the appropriate
medication,
as they can quickly become severe and widespread.
In some dogs it is almost impossible to control the seborrhea and
recurring yeast or bacterial infections, despite the most diligent
efforts of their owners. Various drugs have been tried in these dogs
with varying results. If effective, they are needed life-long and
all have side effects, so they are used only where other measures
fail.
For the veterinarian: There has been some success in the
treatment of cocker spaniels with the retinoic acid etretinate.
Corticosteroids and cytotoxic drugs like methotrexate are used with
some success as well, but the long term use required is associated with
potentially severe side effects.
Breeding advice
Dogs with primary seborrhea and their close relatives (parents and
siblings) should not be used for breeding.
FOR MORE
INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.
Resources
Campbell, K.L. 1997. Diagnosis and management of keratinization
disorders in dogs. ACVIM - Proceedings of the 15th Annual Vet.
Medical Forum. pp 220-222.
Power, H.T., Ihrke, P.J. 1995. The use of synthetic
retinoids in veterinary medicine. In J.D. Bonagura and R.W.
Kirk (eds.) Kirk's Current Veterinary Therapy XII Small Animal
Practice.
p585-590. W.B. Saunders Co., Toronto.
Scott, D.W., Miller, W.H., Griffin, C.E. 1995. Muller and
Kirk's Small Animal Dermatology. pp 737-743 W.B. Saunders Co.,
Toronto. This has a practical and detailed section on clinical
management.
Copyright © 1998 Canine Inherited
Disorders Database. All rights reserved.Revised: October 30, 2001.
This database is funded jointly by the Sir
James Dunn Animal Welfare Centre at the Atlantic Veterinary College,
University of Prince Edward Island, and the Canadian Veterinary Medical
Association.
Permission to reprint granted by
Alice Crook, DVM Coordinator, Sir James Dunn Animal Welfare Centre
Atlantic Veterinary College University of Prince Edward Island
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SCRATCHING THE SURFACE OF CANINE SKIN DISEASE
Dr. Rob Hilsenroth
The skin is the largest organ
in an animal's body. The unique design of the skin allows it to perform
many important functions. Most of the skin is soft, pliable and covered
with hair. In certain areas, however, the skin is custom-made to
perform specific functions, such as that of the nose and the foot pads
of the paws. Skin has the remarkable ability to heal if damaged or to
regrow if removed. Skin can even be surgically removed from one area of
the body and placed in another site to grow É a process called
grafting.
What is the function of skin?
The primary purpose of skin is to protect the body from insults like
trauma and microorganisms. The skin is also responsible for keeping the
dog warm. It does this by producing hair and maintaining an insulating
layer of fat. Specialized skin of the paw pads and tongue allow dogs to
cool themselves by letting moisture evaporate.
The skin helps regulate the body's moisture balance by creating a
barrier to the outside environment. It keeps itself pliable by
producing oils from the glands called sebaceous glands, which are
located all
over the body. Skin oils also contribute to the external barrier
against
bacteria.
The skin is a sensory organ as well; it contains nerve endings called
sensory receptors to provide touch and pain sensation. It's very easy
to take the skin for granted, but it's critical to an animal's
survival.
What kinds of skin diseases can a dog get?
Like any other tissue in the body, the skin is subject to disease.
Despite the wonderful versatility of the skin, it has only a small
number of ways to respond to insult or injury. Disorders of the skin
are often challenging for the veterinarian to diagnose since many skin
diseases look very much alike. In addition, the skin can often be
affected by disease occurring elsewhere in the body. This is referred
to as secondary skin disease.
Skin that is unhealthy can either be dry and flaky, or greasy
with a strong odour. When the skin is unhealthy, the dog's coat is
usually affected. Hair may fall out, creating bald patches, or the hair
may be brittle and dull. Irritated skin is often red and
ÒangryÓ looking. Small raised bumps or crusty scabs may
appear. Diseased skin is uncomfortable and may cause a dog to scratch
excessively, damaging the skin further. Chronically irritated skin can
change colour and become wrinkled and tough.
A common disease of dogs is called seborrhoea. Seborrhoea refers to the
rapid death and subsequent new production of skin cells. Skin cells
normally die off and are replaced at a relatively rapid rate as
compared to other tissues in the body. But the normal rate of turnover
is accelerated with this disease. Seborrhea results in dry, flaky skin
(seborrhoea sicca) or greasy, foul-smelling skin (seborrhoea oleosa).
These conditions allow the skin to become easily infected with bacteria
and yeast which further skin damage and increase the affected dog's
discomfort.
What causes seborrhoea?
Seborrhoea is a skin disease that is often secondary to problems
such as allergies, poor nutrition, mange, hormone deficiencies or
hormone excess. In these cases, if the underlying disease is diagnosed
and treated or cured, the seborrhoea will greatly disappear.
Some dogs are unfortunate enough to be born with seborrhoea as a
primary disease. In these cases, no underlying cause for the disease
can be found. Primary seborrhoea is believed to be an inherited
disorder. It is seen often in the Spaniel and Terrier breeds, and less
commonly in Labrador Retrievers, Doberman Pinschers and Chinese
Shar-Peis. At this time, there is no cure for this disease and dogs
must be carefully managed their whole lives to keep them comfortable.
How can primary seborrhoea be treated?
Dogs with primary seborrhoea are usually treated with shampoos. Owners
often need to bathe their dogs two to three times a week with
therapeutic shampoos just to control the symptoms and try to prevent
skin infections. Skin infections invariably occur, however, requiring
treatment with antibiotics. A group of drugs called retinoids, which
are
derived from vitamin A, have been tried for the treatment of primary
seborrhoea with variable results. These drugs are very expensive and
may have undesirable side effects including eye and liver problems.
What is being done for dogs with primary seborrhoea?
Morris Animal Foundation and the Golden Retriever Club of America
recently funded Dr. Ken Kwochka's study at the Ohio State University
College of Veterinary Medicine. The study, "Treatment of Canine
Idiopathic
Seborrhoea with 1,25-Dihydroxyvitamin D3" explored the possibility of
using a drug called calcitrol (a vitamin D derivative) to control the
symptoms
of primary seborrhoea in dogs. The results of Dr. Kwochka's work
suggest
that calcitrol may be a new and safer alternative to the retinoids for
dogs
with this chronic, uncomfortable disease.
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Rob Hilsenroth, DVM, was the
Executive Director of Morris Animal Foundation.
Morris Animal Foundation is a nonprofit organization
which sponsors animal health studies at veterinary schools and
institutions throughout the U.S and in other parts of the world. All
annual unrestricted contributions to the foundation support health
programs not the cost
of administration or fund-raising. If you'd like to make a
contribution,
write Morris Animal Foundation, 45 Inverness Drive East, Englewood, CO
80112. For more information, please call (800) 243-2345.
The above information is simply
informational. It's intent is not to replace the advice of a
veterinarian nor to assist you in making a diagnosis of your pet.
Please consult with your own veterinarian for confirmation of any
diagnosis. Your pets life may depend on it.
