Canine atopic dermatitis and feline atopic skin syndrome are common presentations in small animal practice. Numerous drugs are used for symptomatic therapy. The only definitive treatment based on the cause of the disease is allergen immunotherapy. Classical allergen immunotherapy (AIT) consists of subcutaneous injections of an extract containing offending allergens, with increasing doses and allergen concentrations at short intervals during the induction phase of several weeks to months followed by a maintenance phase, where a fixed dose is typically given at longer intervals. Dose and interval are tailored to the individual patient. Newer types of AIT include rush immunotherapy, where the induction phase is abbreviated, intralymphatic immunotherapy, and oromucosal or sublingual immunotherapy. AIT aims at inducing a regulatory T-cell response and subsequently downregulating the exaggerated immune response to offending allergens leading to clinical signs. This article reviews the published knowledge about allergen immunotherapy in dogs and cats for small animal practitioners.
Objective—To evaluate the safety of an abbreviated
course of injections of allergen extracts (rush
immunotherapy) for the treatment of dogs with atopic
Animals—30 dogs with atopic dermatitis examined
at a veterinary dermatology referral practice for treatment
with allergen-specific immunotherapy.
Procedure—A catheter was placed in a vein in each
dog. Dogs were constantly observed throughout the
procedure. Allergen extracts were administered in
increasing concentrations every 30 minutes for 6
hours to a maintenance concentration of 20,000 protein
nitrogen units/ml. Epinephrine, oxygen, and
emergency treatment were available as needed.
Results—In 22 (73%) dogs, rush immunotherapy
safely replaced the prolonged induction period (15
weeks) of weekly injections that consists of increasing
concentrations of allergen extract. In 7 (23%)
dogs, the induction period was abbreviated to 4
weeks. Of the 8 dogs that developed problems during
rush immunotherapy, increased pruritus necessitated
premature cessation of rush immunotherapy in
7, and 1 developed generalized wheals. Oral administration
of prednisolone (1 mg/kg of body weight)
resulted in resolution of adverse effects in all 8 dogs.
Conclusion and Clinical Relevance—Rush immunotherapy
performed by personnel at a veterinary hospital
is a safe method for treatment of dogs with
atopic dermatitis. (Am J Vet Res 2001;62:307–310)
Objective—To evaluate the effect of long-term treatment
with tetracycline and niacinamide on antibody
production in dogs by measuring postvaccinal serum
concentrations of antibodies against canine parvovirus
and canine distemper virus.
Animals—10 dogs receiving long-term treatment
with tetracycline and niacinamide (treatment group)
and 10 healthy dogs (control group).
Procedure—The treatment group included 9 dogs
with discoid lupus erythematosus and 1 dog with
pemphigus foliaceus on long-term treatment (> 12
months) with tetracycline and niacinamide. The control
group included 10 healthy dogs with no clinical
signs of disease and no administered medications for
the past 3 months. Blood samples were obtained
from all dogs by jugular venipuncture. Serum antibody
titers against canine parvovirus and canine distemper
virus antigens were measured, using hemaglutination
inhibition and serum neutralization, respectively, and
compared between groups.
Results—A significant difference in antibody titers
between treatment- and control-group dogs was not
found. All dogs had protective antibody titers against
canine distemper virus, and 8 of 10 dogs from each
group had protective titers against canine parvovirus
Conclusion and Clinical Relevance—These results
provide evidence that long-term treatment with tetracycline
and niacinamide does not interfere with routine
vaccinations and thus does not seem to influence
antibody production in dogs. (Am J Vet Res 2002;
Objective—To examine cross-reactivity of aeroallergens
in Colorado and surrounding states by evaluating
concurrent positive reactions of related and nonrelated
allergens of intradermal tests in dogs.
Sample Population—Intradermal test results of 268
Procedure—A retrospective evaluation of skin test
results for 268 dogs was performed. Pairs of closely
related and nonrelated allergens were evaluated.
Group 1 consisted of closely related allergens with
demonstrated antibody cross-reactivity in humans. In
group 2, allergens of the same plant group (ie, trees,
grasses, or weeds) that were not closely related were
paired. In group 3, allergen pairs were of different
plant groups. Plant allergens were paired with dust
mite allergens, animal dander, or mold spores in
group 4. In the last group, allergens not derived from
plants were paired. Data were evaluated twice by use
of a different definition of a positive reaction.
Significance of the difference between group means
of log odds ratios was estimated by use of a bootstrap
percentile confidence interval.
Results—Significant differences in the number of
concurrent positive reactions were not found
between related versus nonrelated grass, weed, or
tree allergens. Significant differences in the number
of concurrent positive reactions were found between
plant allergens of different groups (ie, grasses,
weeds, and trees) and plant allergens of the same
groups, related or nonrelated , as well as between
plant-derived and nonplant-derived allergens. Many
dogs reacting to a specific allergen did not react to a
closely related allergen at the same time.
Conclusion and Clinical Relevance—These results provide evidence against
clinically relevant cross-reactivity and suggest that
allergen-specific immunotherapy should be formulated
on the basis of single allergen test results.
(Am J Vet Res 2002;63:874–879)
Objective—To determine essential fatty acid concentrations
in plasma and tissue before and after supplementation
with n-3 fatty acids in dogs with atopic dermatitis.
Animals—30 dogs with atopic dermatitis.
Procedure—Dogs received supplemental flaxseed oil
(200 mg/kg/d), eicosapentaenoic acid (EPA;
50 mg/kg/d)-docosahexaenoic acid (DHA;
35 mg/kg/d), or mineral oil as a placebo in a doubleblind,
placebo-controlled, randomized trial. Clinical
scores and plasma and cutaneous concentrations of
linoleic acid, arachidonic acid, α-linolenic acid (α-LLA),
EPA, DHA, prostaglandin E2, and leukotriene B4 were
Results—Total plasma concentrations of α-LLA and
EPA increased and those of arachidonic acid
decreased significantly with administration of EPADHA,
and concentrations of α-LLA increased with
flaxseed oil supplementation; nevertheless, there
was no significant change in the concentrations of
these fatty acids or eicosanoids in the skin. There was
no correlation between clinical scores and plasma or
cutaneous concentrations for any of the measured
fatty acids or eicosanoids.
Conclusion and Clinical Relevance—Results indicated
that at the dose used, neither the concentrations
of fatty acids in skin or plasma nor a decrease in
the production of inflammatory eicosanoids was a
major factor involved in the mechanism of action in
dogs with atopy that responded to fatty acid supplementation.
(Am J Vet Res 2005;66:868–873)