The
initial topic, by popular demand, 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.
(1)
The bumps are actually hive-like reactions that occur
at individual hair follicles;
(2) 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;
(3) By-products of bacterial life cycles can cause
intense itching in the skin, aggravating the initial
itchiness;
(4) Hair loss (alopecia) is a result of folliculitis
stopping the growth of hair;
(5) 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;
*lusion 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:
(1) We have a more or less allergic dog;
(2)
We groom this dog with whitening shampoos that strip
natural protective oils from skin and coat;
(3)
We travel, exposing him to unfamiliar allergens and
possibly fleas;
(4) Change in daily routine produces physiological
stress and subsequently a somewhat suppressed immune
response;
(5)
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,
antiinflammatory 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 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.
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 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:
Email:
snowhill@earthlink.net
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