The Dalmatian Club of America
Skin and Coat Disorders in Dalmatians
by
Susanne A. Hughes, DVM
Study Group on Skin & Allergic Disorders
Dalmatian Club of America
By popular demand, the initial topic for consideration
by the DCA Study Group on Skin & Allergic Disorders is that all-too-common
and frustrating syndrome referred to by fanciers as "Dal crud."
I will discuss this topic specifically as it relates to dogs being actively
campaigned in conformation or obedience.
A typical scenario may be the following: the light of
your life has a flawless coat while running in the backyard at home and
swimming in scummy ponds. He may even tolerate a flea or two. He is groomed
and shampooed on Thursday for the weekend shows. By Saturday, bumps start
appearing, usually on the top of the dog's head and/or along his back.
Left unchecked, the bumps spread and often become very itchy (pruritic).
A significant proportion of these lesions, interestingly, may not itch
but still progress as follows. Each bump is actually an inflamed hair follicle
that oozes a bit of serum, which may be noticed only as it dries in the
form of scabs. Within a few days, hair loss occurs at the site of each
bump. Eventually the coat looks moth-eaten. Additionally, white hairs take
on a pinkish-bronze cast at the sites of the original bumps, and now your
hopes and vision of the judge nodding in your direction begin to fade.
At this stage itching is variable.
What is the cause (etiology) of this skin disorder? How
do we treat it? More importantly, how can we prevent it? Is this what is
referred to as the "Dalmatian Bronzing Syndrome"? Does the
"Dalmatian Bronzing Syndrome" really exist as a diagnostic
entity? The answers to most of these questions are relatively straightforward.
Let us address these issues in sequence leaving the question of cause for
last.
-
The bumps are actually hive-like reactions that occur at
individual hair follicles;
-
When inflammation of the follicles (folliculitis) occurs,
we see secondary infection (superficial pyoderma) by Staphylococcus
intermedius, which is one of the normal bacterial flora found on
all dogs' skin;
-
By-products of bacterial life cycles can cause intense itching
in the skin, aggravating the initial itchiness;
-
Hair loss (alopecia) is a result of folliculitis stopping
the growth of hair;
-
Remaining hairs are stained by pigments called porphyrins
in the serum which ooze out during the inflammatory process.
The final and lasting result of all this is the "bronzed"
appearance of the coat. The discolored hairs are permanently stained and
little can be done to whiten a coat so affected. Of course this bronzing
occurs just as frequently in colored coats, but is not as apparent.
The central issue of this syndrome, however, remains to
be addressed: Why do the hive-like reactions occur in the first place?
The answers are many:
1) Allergy. A large majority of Dalmatians
exhibiting these signs are allergic. Many scientific surveys statistically
list our beloved breed as one of the most commonly represented allergic
purebreds, based on repeatedly positive skin tests to assorted substances
known to cause allergic reactions (allergens). These allergens may be inhaled
as in the case of airborne pollens, molds, etc.; ingested
as with food allergens; injected as with flea saliva; or
merely contacted as with local irritants coming in contact
with the skin.
2) Stress. Add to allergy the physiological
stress associated with travel, excitement, change in routine and diet (all
that baiting!). Biologically, stress is associated with an increase in
production of steroid hormones called glucocorticoids. Normally, glucocorticoids
allow dogs to meet the special needs of stressful situations, but they
may also have the unfortunate effect of decreasing the "barrier function"
of normal canine skin. When inflammation already exists, the glucocorticoid
response may permit bacteria, normally kept in check on the skin, to flourish.
3) Humidity and Heat. Veterinary dermatologists
consider changes in humidity and temperature also to be significant factors
in the onset of these hive-like reactions. These changes may be associated
with the ambient or skin environment, such as:
-
climatic differences between home and the show site;
-
drying of the skin;
-
occlusion of pores in the skin by special grooming products.
It has been suggested that the non-itching form of this syndrome
is more directly related to these environmental conditions than it is to
allergies.
PREVENTION
Veterinary dermatologists are convinced that flea and
inhalant allergies in dogs are hereditary. Certainly the best preventative
medicine is to eliminate affected dogs from the breeding population. Some
conscientious breeders have had great success in establishing lines with
consistently good coats by simply avoiding the breeding of visibly affected
dogs who exhibit chronically troublesome coats.
There is less agreement, on the other hand, about the
hereditary nature of food allergies in dogs. As guardians of the Dalmatian
breed, we must plan our breedings for general good health as carefully
as we plan for that dynamite puppy that will knock 'em dead at the next
DCA!
For those of us who have not quite accomplished coat-nirvana
in our breeding programs, a little forethought and care may allow us to
avert an impending coat disaster. A quick review of the situation allows
us to enumerate potential problems and then formulate solutions:
-
We have a more or less allergic dog;
-
We groom this dog with whitening shampoos that strip natural
protective oils from skin and coat;
-
We travel, exposing him to unfamiliar allergens and possibly
fleas;
-
Change in daily routine produces physiological stress and
subsequently a somewhat suppressed immune response;
-
Using bait alters the normal diet and may negatively affect
those dogs who have a component of food allergy as part of this syndrome.
The following preventative measures have generally proven
effective and safe with no long-term contraindications or negative side
effects.
For the last few years veterinary dermatologists have
been prescribing fatty acid supplementation (Derm Caps, EFA Caps, OM Caps,
etc.) for those dogs shown to be allergic. Fatty acids act as immunomodulators,
anti-inflammatory agents, and are especially important in helping the body
maintain the integrity of skin as a barrier to infectious agents. Other
beneficial side effects include optimum hair growth and luster. Although
debate continues as to the ideal ratios of specific fatty acids, most dermatologists
agree these supplements should contain a combination of vegetable and fish
oils. Recent data suggests these supplements should be administered at
two to three times the manufacturer's recommended dose. (Note that some
dogs will develop diarrhea if given doses higher than the recommended one.)
Another important note: the effects of fatty acid supplementation will
not become apparent for four to eight weeks and so should be part of long-term
nutritional support. I recommend supplementation for the dog's entire show
career, and in some cases, for its entire life. Fatty acids may not entirely
prevent episodes of "the crud", but they allow the skin to function optimally
under adverse circumstances.
Fatty acids have recently been shown in allergic dogs
to act synergistically with antihistamines by helping to block the initial
reaction to offending allergens. In several studies, dogs receiving both
fatty acid supplements and antihistamines responded better with fewer,
less severe bouts of itching and secondary skin infection than did those
receiving either compound alone. Additionally, all dogs continuously receiving
antihistamines responded better than those treated only when scratching
was observed.
For breeders, this translates to a prevention protocol
advocated by Carroll H. Weiss (Dalmatian fancier and Professor of Dermatology,
U. of Miami School of Medicine), myself, other practitioners and veterinary
dermatologists. Several days prior to an anticipated allergic challenge
(dog show), begin preventative antihistamine therapy and continue it until
you return home. Like Professor Weiss' suggestions, I usually choose to
prescribe chlorpheniramine maleate (Chlor-Trimeton), 12 mg., two to three
times daily. This is an inexpensive antihistamine available without a prescription
that tends to produce less drowsiness than many other antihistamines. (For
those dogs experiencing dullness after they receive their antihistamine,
wait until after showing to dose them. Duration of activity is short, so
this effect should be inapparent by the next morning.)
Individual response to specific antihistamines is variable
so do not despair if your initial choice is ineffective. Other potentially
effective choices include diphenhydramine (Benadryl), clemastine (Tavist),
and hydroxyzine (Atarax).
The rest of the prevention protocol involves common sense
management:
-
Keep the Dalmatians free of fleas;
-
Use hypoallergenic shampoos, alternating with antibacterial
shampoos if necessary. Do not bathe them too frequently;
-
Avoid baits known to induce allergic reactions. These foodstuffs
will vary from dog to dog and may require extensive trial and error to
identify. When possible use a single source protein bait such as all-turkey
hot-dogs as opposed to Rollover.
Remember that no studies have been published which have examined
large groups of allergic Dalmatians. Anecdotal evidence gathered from dermatologists
in academic and referral centers is compatible with published statistics
of allergic dogs: approximately 10% have food allergies and 90% have inhalant
allergies.
TREATMENT
If your dog begins to "bump up" despite your best efforts
or in lieu of preventative measures, then aggressive treatment is necessary
to save some coat for the next couple of show circuits. Topical treatment
with benzoyl peroxide (Oxydex, Pyoben) or chlorhexidine shampoos (Chlorhexiderm,
Nolvasan) act to cleanse the skin, removing superficial bacteria. Under
these circumstances, it may be necessary to bathe weekly, following with
a hypoallergenic oatmeal creme rinse to prevent excessive drying of the
skin and compromise of the skin barrier.
Systemic antibiotics are always indicated in cases of
folliculitis. Unfortunately, skin needs to be treated for three to four
weeks even in uncomplicated cases. If response is not noted within seven
to ten days of antibiotic therapy, reevaluation of the antibiotic being
used is warranted. Antibiotics chosen as first line therapeutic agents
should be those known to be effective against Staphylococcus intermedius.
Both prescriptions by veterinarians, and response by bacteria to antibiotics,
vary regionally but appropriate choices include: oxacillin, cephalexin,
ormetaprim-sulfas and, in some instances, amoxicillin with clavulanic acid.
It is vitally important that appropriate treatment regimens are followed
conscientiously.
For recurrent pyodermas that cannot be controlled by preventative
measures outlined above, your veterinarian should recommend further workup
to definitively rule in or out any allergies, endocrine disorders, seborrhea,
Staphylococcal hypersensitivity or rarely, immunocompromise.
THE "DALMATIAN BRONZING SYNDROME"
I mentioned this "syndrome" earlier when discussing the
bronze staining of white hairs by serum pigments called porphyrins. The
bronzed Dal typically appears to have a broad stripe of pinkish - bronzed
coat along the topline often including the head. Close examination of the
hair shafts reveals staining from the skin to extend also to varying levels
of the hair shafts. Early reports attempted to link this staining to other
Dalmatian health problems including urinary urate crystals, dietary allergies,
protein intolerance, demodecosis, and sarcoptic mange, and to call the
collection of disorders, the "Dalmatian Bronzing Syndrome". Dermatologists
are skeptical that this is a syndrome definitely associated with these
other maladies or unique to Dalmatians. Most believe instead that it is
the natural result of follicular inflammation described previously. Obviously,
white coated breeds will exhibit the staining most dramatically.
Despite this skepticism in the veterinary community, a
new study is getting underway at North Carolina State University College
of Veterinary Medicine examining the "red hair syndrome" of many breeds.
This is a problem reported more frequently in Europe than the United States,
but closely parallels what has been referred to as the "Dalmatian Bronzing
Syndrome" here. Researchers will be studying the structure of hair shafts
by electron microscopy. Anyone interested in participating by supplying
hairs for examination should contact me for more information:
Susanne A. Hughes, DVM
snowhill@earthlink.net
3013 Ridge Road
Durham, North Carolina 27705
Tel. (919) 489-1367
Fax (919) 489-5838
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