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In human patients with seasonal allergic rhinoconjunctivitis sensitized to grass pollen, the first successful allergen immunotherapy (AIT) was reported in 1911. Today, immunotherapy is an accepted treatment for allergic asthma, allergic rhinitis and hypersensitivities to insect venom. AIT is also used for atopic dermatitis and recently for food allergy. Subcutaneous, epicutaneous, intralymphatic, oral and sublingual protocols of AIT exist. In animals, most data are available in dogs where subcutaneous AIT is an accepted treatment for atopic dermatitis. Initiating a regulatory response and a production of "blocking" IgG antibodies with AIT are similar mechanisms in human beings and dogs with allergic diseases. Although subcutaneous immunotherapy is used for atopic dermatitis in cats, data for its efficacy are sparse. There is some evidence for successful treatment of feline asthma with AIT. In horses, most studies evaluate the effect of AIT on insect hypersensitivity with conflicting results although promising pilot studies have demonstrated the prophylaxis of insect hypersensitivity with recombinant antigens of biting midges (Culicoides spp.). Optimizing AIT using allergoids, peptide immunotherapy, recombinant allergens and new adjuvants with the different administration types of allergen extracts will further improve compliance and efficacy of this proven treatment modality.

Cross-reactive carbohydrate determinants (CCD) are Immunoglobulin E (IgE)-binding carbohydrate structures common to plant and insect species. In people, anti-CCD IgE is thought to be clinically irrelevant, but to have the potential to confound serological IgE test interpretations. Previous studies reported the detection of anti-CCD IgE in 24-73% of atopic dog sera; prevalence in healthy dogs has not been reported.To compare the prevalence of anti-CCD IgE in a group of healthy and atopic dogs.Sera from 61 healthy dogs and 101 dogs with a clinical diagnosis of atopic dermatitis were analyzed for IgE against CCD.Sera were analyzed for the presence of anti-CCD IgE and IgE against environmental allergens using a commercial multiplex allergen-specific IgE assay.Anti-CCD IgE was detected in 17 of 101 (16.8%) atopic dog sera and eight of 61 (13.1%) healthy dog sera (P = 0.65, Fisher's exact test). All healthy and atopic dogs with anti-CCD IgE had strong reactivity to grass pollens.A similar prevalence of anti-CCD IgE was found in healthy and atopic dogs. Further investigation is warranted to determine the clinical significance of anti-CCD IgE antibodies in dogs, how they are best detected and if blocking these antibodies during diagnostic testing has clinical value.Les CDD (cross-reactive carbohydrate determinants) sont des carbohydrates porteurs d'immunoglobulines E (IgE) fréquents pour les plantes et les insectes. Chez l'homme, les IgE anti-CDD sont considérés comme non significatifs cliniquement mais ayant un potentiel de confusion d'interprétation des tests sérologiques d'IgE. Les études précédentes rapportent la détection des IgE anti-CDD dans 24-73% des sera des chiens atopiques ; la prévalence chez le chien sain n'a pas été décrite.Comparer la prévalence des IgE anti-CDD dans un groupe de chiens sains et atopiques.Les sera de 61 chiens sains et 101 chiens atteints de dermatite atopique ont été analysés pour les IgE anti CDD. MATÉRIELS ET MÉTHODES: Les sera ont été analysés pour la présence des IgE anti-CDD et les IgE dirigés contre les allergènes environnementaux à l'aide d'un test commercial multiplex d'IgE spécifique d'allergènes. RÉSULTATS: Les IgE anti-CDD étaient détectés dans 17 des 101 (16,8%) sera de chiens atopiques et huit des 61 (13,1%) sera des chiens sains (P = 0.65, Fisher's exact test). Tous les chiens sains et atopiques avec IgE anti-CDD avaient une forte réactivité aux pollens d'herbe.Une prévalence identique d'IgE anti-CDD a été trouvée chez les chiens sains et atopiques. Davantage d’études sont nécessaires pour déterminer la signification clinique des anticorps IgE anti-CDD chez le chien, comment les détecter au mieux et si leur blocage au cours des tests diagnostics ont une valeur clinique.INTRODUCCIÓN: los determinantes de carbohidratos con reactividad cruzada (CCD) son estructuras de carbohidratos que se unen a la inmunoglobulina E (IgE) comunes a especies de plantas e insectos. En las personas, se cree que la IgE anti-CCD es clínicamente irrelevante, pero tiene el potencial de confundir las interpretaciones de la prueba de IgE serológica. Estudios anteriores informaron de la detección de IgE anti-CCD en un 24 a 73% de los sueros atópicos para perros; no se ha publicado la prevalencia en perros sanos. OBJETIVO: comparar la prevalencia de IgE anti-CCD en un grupo de perros sanos y atópicos. ANIMALES: se analizaron los sueros de 61 perros sanos y 101 perros con diagnóstico clínico de dermatitis atópica para detectar IgE contra CCD. MÉTODOS Y MATERIALES: se analizaron los sueros para determinar la presencia de IgE e IgE anti-CCD contra alérgenos ambientales usando un ensayo comercial de IgE multiplex específico para alérgenos. RESULTADOS: se detectó IgE anti-CCD en 17 de 101 (16,8%) de sueros de perros atópicos y ocho de 61 (13,1%) sueros de perros sanos (P = 0,65, prueba exacta de Fisher). Todos los perros sanos y atópicos con IgE anti-CCD tuvieron una fuerte reactividad a los pólenes de hierba. CONCLUSIONES E IMPORTANCIA CLÍNICA: se encontró una prevalencia similar de IgE anti-CCD en perros sanos y atópicos. Se justifica una investigación adicional para determinar la importancia clínica de los anticuerpos IgE anti-CCD en perros, cómo se detectan mejor y si el bloqueo de estos anticuerpos durante las pruebas de diagnóstico tiene valor clínico.Kreuz-reaktive Kohlenhydrat Determinanten (CCD) sind Immunglobulin E (IgE)- bindende Kohlenhydrat Strukturen, die für Pflanzen und Insekten Spezies typisch sind. Beim Menschen hält man anti-CCD IgE für klinisch irrelevant, aber man geht davon aus, dass sie das Potential haben, die serologischen IgE Interpretationen durcheinander zu bringen. Frühere Studien berichteten vom Auftreten von anti-CCD IgE bei 24-73% der atopischen Sera von Hunden; die Prävalenz bei gesunden Hunden wurde bisher nicht publiziert. ZIEL: Ein Vergleich der Prävalenz von anti-CCD IgE in einer Gruppe gesunder und atopischer Hunde.Sera von 61 gesunden Hunden und von 101 Hunden mit der klinischen Diagnose einer atopischen Dermatitis wurde auf IgE gegen CCD analysiert.Es wurden Sera auf das Vorkommen von anti-CCD IgE und IgE gegen Umweltallergene mittels kommerziellem Multiplex Allergen-spezifischem IgE Assay getestet.Anti-CCD IgE wurde bei 17 von 101 (16,8%) Sera von atopischen Hunden und bei acht von 61 (13,1%) Sera von gesunden Hunden (P = 0,65; Fisher´s Exact Test) gefunden. Alle gesunden und atopischen Hunde mit anti-CCD IgE zeigten eine stark positive Reaktivität zu Graspollen.Eine ähnliche Prävalenz von anti-CCD IgE wurde bei gesunden und atopischen Hunden gefunden. Weitere Untersuchungen sind nötig, um die klinische Signifikanz von anti-CCD IgE Antikörpern bei Hunden zu bestimmen, wie sie am besten bestimmt werden und ob ein Blockieren dieser Antikörper während dem diagnostischen Test von klinischem Wert ist.背景: 交差反応性炭水化物決定因子(CCD)は、植物および昆虫種に共通の免疫グロブリンE(IgE)結合炭水化物構造物である。人においては、抗CCD IgEは臨床的に無関係であると考えられているが、血清学的IgE検査の解釈を混乱させる可能性があると考えられている。既存の研究では、アトピー犬血清の24〜73%で抗CCD IgEが検出されたことが報告されている。健常犬の有病率は報告されていない。 目的: 本研究の目的は、健常犬群とアトピー犬群における抗CCD IgEの有病率を比較することである。 被験動物: 健常犬61頭およびアトピー性皮膚炎の臨床診断を受けた犬101頭の血清を、CCDに対するIgEについて解析した。 材料と方法: 市販の多重アレルゲン特異的IgEアッセイを用いて、血清を抗CCD IgEの存在および環境アレルゲンに対するIgEについて解析した。 結果: 抗CCD IgEは、101頭中17頭(16.8%)のアトピー犬血清と61頭中8頭(13.1%)の健常犬血清で検出された(P = 0.65、フィッシャーの正確検定)。抗CCD IgEを有した健常犬およびアトピー犬はすべて、イネ科植物の花粉に対して強い反応性を示した。 結論と臨床的重要性: 健常犬およびアトピー犬において、類似した抗CCD IgE有病率を検出した。犬における抗CCD IgE抗体の臨床的意義、それらの最良の検出方法、および診断検査中にこれらの抗体をブロッキングすることが臨床的価値を有するかどうかを判断するにはさらなる調査が必要である。.背景: 交叉反应性碳水化合物决定簇(CCD)是植物和昆虫常见的免疫球蛋白E(IgE)结合碳水化合物的结构。人们认为抗CCD IgE在临床上无关紧要,但有可能扰乱对血清学IgE检测的判读。先前的研究报道了在24-73%的异位性犬血清中检测到了抗CCD IgE;而健康犬的检出率尚未见报道。 目的: 比较一组健康和异位性犬中抗CCD IgE的检出率。 动物: 分析61例健康犬和101例临床诊断为异位性皮炎犬的血清抗CCD的IgE。 方法和材料: 使用多种商业化过敏原特异性IgE测定法,检测血清中抗CCD IgE和环境过敏原IgE的存在。 结果: 在101例异位性犬血清中有17例(16.8%)抗CCD IgE;61例(13.1%)健康犬血清中有8例检测到了抗CCD IgE(P = 0.65,Fisher精确检验)。所有具有抗CCD IgE的健康和异位性犬对草花粉都有较强的反应性。 结论和临床意义: 在健康和异位性犬中发现了类似的抗CCD IgE检出率。有必要进行进一步的研究,以确定抗CCD IgE抗体在犬体内的临床意义,如何最好地检测这些抗体,以及在诊断试验中阻断这些抗体是否具有临床价值。.Os determinantes de carboidratos de reação cruzada (CCD) são estruturas de carboidratos que se ligam à imunoglobulina E (IgE), comuns a espécies de plantas e insetos. Em humanos, acredita-se que a IgE anti-CCD seja clinicamente irrelevante, mas possua o potencial de confundir interpretações do teste sorológico de IgE. Estudos anteriores relataram a detecção de IgE anti-CCD em 24-73% dos soros de cães atópicos; a prevalência em cães saudáveis não foi relatada.Comparar a prevalência de IgE anti-CCD em um grupo de cães saudáveis e atópicos.Os soros de 61 cães saudáveis e 101 cães com diagnóstico clínico de dermatite atópica foram pesquisados para a presença de IgE contra CCD. MÉTODOS E MATERIAIS: Os soros foram analisados quanto à presença de anti-CCD IgE e IgE contra alérgenos ambientais utilizando um ensaio multiplex comercial de IgE alérgeno-específico.A IgE anti-CCD foi detectada em 17 dos 101 (16,8%) soros de cães atópicos e oito dos 61 (13,1%) soros de cães saudáveis (P = 0,65, teste exato de Fisher). Todos os cães saudáveis e atópicos que tiveram IgE anti-CCD apresentaram forte reatividade ao pólen da gramíneas. CONCLUSÕES E IMPORTÂNCIA CLÍNICA: Observou-se uma prevalência semelhante de IgE anti-CCD em cães saudáveis e atópicos. Uma investigação mais aprofundada é necessária para determinar o significado clínico dos anticorpos IgE anti-CCD em cães, sua melhor forma de detecção e valor clínico do bloqueio desses anticorpos durante o teste diagnóstico.

In this study, dogs with atopic dermatitis were separated into non-food-induced atopic dermatitis (NFIAD) group (n = 15) and food-induced atopic dermatitis (FIAD) group (n = 37) based on an elimination diet test. IgE reactivity for crude Malassezia pachydermatis (M. pachydermatis) and house dust mites (HDM) allergen extracts was investigated in the two groups using fluorometric enzyme-linked immunosorbent assay (ELISA) and intradermal skin test (IDST). Nine (60%) of the 15 dogs in NFIAD group and 6 (16%) of the 37 dogs in FIAD group showed specific IgE for M. pachydermatis (Mann-Whitney U-test, P 0.01). By immunoblotting analysis, the pooled serum samples from dogs with IgE for M. pachydermatis showed IgE reactivity for 50 kDa protein of M. pachydermatis. Twelve (80%) of the 15 dogs in NFIAD group and 8 (22%) of the 37 dogs in FIAD group showed specific IgE for HDM (Mann-Whitney U-test, P 0.01). In addition, the dogs in NFIAD group significantly show a positive IDST to M. pachydermatis and HDM extracts compared with the dogs in FIAD group. The results suggest that dogs with NFIAD are at increased risk of becoming sensitized to the normal commensal organism M. pachydermatis compared with dogs with FIAD, perhaps co-sensitization occurred due to an HDM protease antigen's, Der f 1 and/or Der p 1, proteolytic activity related epidermal skin barrier defects. Treatment to limit skin colonization may thus be especially important in NFIAD.

Dogs with cutaneous adverse food reactions (CAFR) often have specific IgE to food allergens. Egg white, which is majorly composed of ovomucoid, ovalbumin, ovotransferrin, and lysozyme, is a food allergen in dogs. Information of the IgE reactivity to purified egg white allergens supports accurate diagnosis and efficiency treatment in humans. However, to the best of our knowledge, there have been no studies on the IgE reactivity to purified egg white allergens in dogs. Here, we investigated the IgE reactivity to crude and purified allergens of hen egg white in dogs with CAFR. First, when we examined serum samples from 82 dogs with CAFR for specific IgE to crude egg white by ELISA, 9.8% (8/82) of the dogs with CAFR showed the IgE reactivity to crude egg white. We then used sera from the eight dogs with positive IgE reactivity to crude egg white to examine the IgE reactivity to four purified allergens, ovomucoid, ovalbumin, ovotransferrin, and lysozyme, by ELISA. We found that 75% (6/8) of the dogs showed IgE reactivity to both ovomucoid and ovalbumin, and that 37.5% (3/8) of the dogs showed IgE reactivity to ovotransferrin. None (0/8) showed IgE reactivity to lysozyme. Moreover, validating these results, the immunoblot analyses were performed using the sera of the three dogs showing the highest IgE reactivity to crude egg white. Both anti-ovomucoid and anti-ovalbumin IgE were detected in the sera of these dogs, while anti-ovotransferrin IgE was not detected. Considering these, ovomucoid and ovalbumin appears to be the major egg white allergens in dogs with CAFR.

The present study investigated IgE reactivity to a new Cryptomeria japonica pollen allergen (Cry j 3) in dogs with atopic dermatitis by using a fluorometric ELISA. Serum samples from 15 dogs that showed IgE sensitivity to crude C. japonica pollen allergen by ELISA were tested for specific IgE to each allergen, individually. All 15 dogs had anti-Cry j 1 IgE, 6 (40%) had anti-Cry j 2 IgE, and 11 (73%) had anti-Cry j 3 IgE. Further, we found that these anti-Cry j 3 IgE reacted to Cry j 3 with immunoblotting analysis. These findings indicate that Cry j 3 may be a major allergen in dogs.

Immediate-type hypersensitivity (ITH), mediated by IgE, to Malassezia pachydermatis is recognized in atopic dogs with recurrent yeast dermatitis and otitis externa (OE). Malassezia-associated OE commonly occurs in dogs without other signs of atopic dermatitis (AD). The aim of this study was to detect Malassezia-specific IgE in the sera of dogs with recurrent Malassezia OE without concurrent skin disease. Sera from healthy dogs were used for comparison. An FceRIα-based ELISA was used to measure Malassezia-specific IgE. There was no significant difference between number of positive affected dogs (6/21, 29%) and number of positive unaffected dogs (15/86, 17%) (P=0.36). There was also no significant difference in the concentrations of Malassezia-specific IgE between the two groups (P=0.97). Malassezia-specific IgE did not distinguish between patient groups so, as with other canine allergens, serum IgE reactivity for Malassezia could not be used to differentiate between diseased and healthy patients. The presence of Malassezia-specific IgE in some of the affected dogs might indicate ITH to Malassezia in those dogs. Evaluation of ITH via intradermal test reactivity and response to allergen-specific immunotherapy might clarify the role of Malassezia-associated ITH in similarly affected dogs.

Background Sublingual immunotherapy (SLIT) has been reported to be beneficial in people with atopic dermatitis (AD) and dust mite sensitivity. Evaluation of this therapy has not been reported in spontaneous canine AD. Objectives The objective of this study was to preliminarily evaluate the effectiveness of an established SLIT protocol, as used in human patients, in dogs with AD. Animals Ten dust mite sensitive dogs with spontaneous AD. Methods Dogs underwent a 6 month open trial of SLIT concurrently with decreasing dose oral methylprednisolone. Clinical evaluations and quantitative serum anti-mite IgE and IgG levels were performed every 2 months. Results Mean methylprednisolone use from the first 2 months of the study to the final 2 months declined from 10.2 to 4.3 mg/kg/2 months (P < 0.001, Student's paired t-test); at 6 months, four dogs required no oral corticosteroid administration. Over the course of the study, median Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03 scores declined from 76.5 to 59; median pruritus scores declined from 65 to 37 (P < 0.02 and P < 0.01, respectively; Wilcoxon signed-rank test). Pre- and post-SLIT intradermal test scores for mite allergen were not significantly different over time. Median Dermatophagoides farinae (DF)-specific IgE levels declined significantly from 150.2 × 103 AU/mL to 3.6 × 103 AU/mL (P < 0.05). Concurrently, median DF-specific IgG levels increased from 18.5 × 106 AU/mL to 3923.4 × 106AU/mL (P < 0.05; Wilcoxon signed-rank tests). Conclusions and clinical importance SLIT treatment produced clinical improvement in dogs with dust mite-associated AD and was associated with serological changes supporting this improvement. Further studies in larger numbers of dogs and those with polysensitization are warranted.

Background In 2010, the International Task Force on Canine Atopic Dermatitis (now International Committee on Allergic Diseases of Animals, ICADA) published the first consensus guidelines for the treatment of atopic dermatitis (AD) in dogs. This is the first 5-year minor update of this document. Results The treatment of acute flares of AD should involve the search for, and then elimination of, the cause of the flares, bathing with mild shampoos, and controlling pruritus and skin lesions with interventions that include topical and/or oral glucocorticoids or oclacitinib. For chronic canine AD, the first steps in management are the identification and avoidance of flare factors, as well as ensuring that there is adequate skin and coat hygiene and care; this might include more frequent bathing and possibly increasing essential fatty acid intake. The medications currently most effective in reducing chronic pruritus and skin lesions are topical and oral glucocorticoids, oral ciclosporin, oral oclacitinib, and, where available, injectable recombinant interferons. Allergen-specific immunotherapy and proactive intermittent topical glucocorticoid applications are the only interventions likely to prevent or delay the recurrence of flares of AD. Conclusions This first 5-year minor update of the international consensus guidelines for treatment of AD in dogs further establishes that the treatment of this disease is multifaceted, and that interventions should be combined for a proven (or likely) optimal benefit. Importantly, treatment plans are likely to vary between dogs and, for the same dog, between times when the disease is at different stages. Electronic supplementary material The online version of this article (doi:10.1186/s12917-015-0514-6) contains supplementary material, which is available to authorized users.

Eight dogs with cutaneous lesions, clinical signs and cytological findings compatible with bacterial overgrowth syndrome were compared with four healthy dogs. The affected dogs were treated for 28 days with 30 mg/kg/day cephalexin. The results showed that the syndrome was a superficial cutaneous disorder characterised by marked pruritus, greasy seborrhoea, offensive odour, erythema, lichenification, hyperpigmentation, excoriations and alopecia involving principally the ventral aspect of the body, but no papules, pustules, epidermal collarettes or crusts; it was caused by overgrowths of Staphylococcus intermedius all over the body surface. Histopathological findings included a superficial, perivascular, hyperplastic and spongiotic dermatitis with a mixed inflammatory infiltrate, but no lesions suggestive of a true pyoderma. In the affected dogs, anti-staphylococcal immunoglobulin G levels were high, but anti-staphylococcal immunoglobulin E levels were low, suggesting that staphylococcal hypersensitivity is not the underlying pathogenic process. The antibiotic treatment improved the condition of all the dogs, but five of the eight had an underlying allergic skin disease.

The efficacy of pharmacological interventions used to treat canine atopic dermatitis, excluding fatty acid supplementation and allergen-specific immunotherapy, was evaluated based on the systematic review of prospective clinical trials published between 1980 and 2002. Studies were compared with regard to design characteristics (randomization generation and concealment, masking, intention-to-treat analyses and quality of enrolment of study subjects), benefit (improvement in skin lesions or pruritus scores) and harm (type, severity and frequency of adverse drug events) of the various interventions. Meta-analysis of pooled results was not possible because of heterogeneity of the drugs evaluated. Forty trials enrolling 1607 dogs were identified. There is good evidence for recommending the use of oral glucocorticoids and cyclosporin for the treatment of canine atopic dermatitis, and fair evidence for using topical triamcinolone spray, topical tacrolimus lotion, oral pentoxifylline or oral misoprostol. Insufficient evidence is available for or against recommending the prescription of oral first- and second-generation type-1 histamine receptor antagonists, tricyclic antidepressants, cyproheptadine, aspirin, Chinese herbal therapy, an homeopathic complex remedy, ascorbic acid, AHR-13268, papaverine, immune-modulating antibiotics or tranilast and topical pramoxine or capsaicin. Finally, there is fair evidence against recommending the use of oral arofylline, leukotriene synthesis inhibitors and cysteinyl leukotriene receptor antagonists.

Background Cross-reactive carbohydrate determinants (CCD) are defined carbohydrate portions of glycoprotein cell surface molecules common to many plant and insect species. Mammalian species recognize CCD as foreign antigens and can mount humoral immune responses against them. Approximately 20-37% of grass and venom allergic people possess circulating IgE against CCD; these antibodies are generally considered clinically irrelevant. Anti-CCD IgE is, however, recognized as a cause of false positive, clinically incongruent serum allergen test results in people; this phenomenon has not been investigated in animals. Objective To determine if anti-CCD IgE could be detected in sera of client-owned atopic dogs and how frequently it is found. Animals Sera from 38 dogs with a clinical diagnosis of atopic dermatitis and prior serological evidence of IgE antibodies, defined as a positive result to at least one mite and pollen (of any type). Methods Sera were analysed for IgE against CCD and environmental allergens with a commercially available multiplex enzyme-labelled allergen-specific IgE assay. Results Anti-CCD IgE was detected in nine of 38 (24%) of atopic dog sera. As with their human counterparts, all dogs with anti-CCD IgE had strong serological reactivity to grass pollens. Conclusions and clinical importance Anti-CCD IgE can confound serological allergen testing in people; the same might be true in dogs. Further studies are warranted to investigate the clinical implications of anti-CCD IgE in dogs, including the potential for these antibodies to affect serum allergen-specific IgE assays used for clinical diagnosis, and whether they are relevant to clinical disease.

Malassezia pachydermatis is part of the normal flora of canine skin. Malassezia hypersensitivity is recognized as a trigger for clinical signs of atopic dermatitis (AD) in some dogs. Determinations of Malassezia hypersensitivity are often made with intradermal testing (IDT), which may have limited availability in a first-opinion veterinary practice.The purpose of this study was to compare immediate IDT reactivity to M. pachydermatis with results of an enzyme-linked immunosorbent assay (ELISA) designed to detect anti-Malassezia IgE.Eighty-four dogs with a clinical diagnosis of AD.Multi-allergen IDT was performed on all dogs. Serum testing for allergen-specific IgE against a panel of common environmental allergens and M. pachydermatis was performed by ELISA using the FcεRIα receptor fragment as a detection reagent, with results reported as adjusted optical density (OD). A receiver operating characteristic (ROC) curve was used to analyse the results of the two tests.The median adjusted OD of the anti-Malassezia IgE ELISA for dogs reactive and nonreactive to M. pachydermatis on IDT was 0.137 and 0.024, respectively. Analysis of the ROC curve suggested a cut-off point for the anti-Malassezia ELISA that yielded a sensitivity of 77.0% and a specificity of 89% relative to IDT results.Substantial agreement was demonstrated between IDT reactivity and anti-Malassezia IgE as detected by the FcεRIα receptor reagent. Although correlation with a clinical diagnosis of Malassezia dermatitis was not attempted in this study, the results indicate that the ELISA may be used to demonstrate the presence of immediate-type Malassezia hypersensitivity in dogs with AD.

Antihistamines frequently are recommended by veterinary dermatologists for symptomatic treatment of pruritus associated with canine atopic dermatitis (AD), perhaps because of their moderate success in some human patients with AD. A critical review of the literature describing antihistamine use in canine AD reveals that the majority of published, peer-reviewed studies are open, uncontrolled or partially-controlled trials. Such studies vary widely in reported efficacy, from perhaps 0 to 75% of patients, even using the same drug. The few blinded placebo-controlled trials available have failed to confirm efficacy of these drugs to relieve the pruritus of canine AD. Some studies indicate that synergistic effects could occur with concurrent use of essential fatty acid supplements. Consequently, at the time of this writing, there is insufficient evidence to conclude for or against the efficacy of antihistamines for treatment of canine AD. Additional blinded, randomized and controlled trials with larger numbers of patients are necessary to establish which of the antihistamine drugs currently available, if any, are truly efficacious for canine AD. Nevertheless, present clinician consensus suggests that several different antihistamine drugs should be evaluated in sequence, for 7-14 days each, in canine patients with AD.

Canine atopic diseases, including those with skin lesions, have been described for many years. Unfortunately, early descriptions often failed to establish definitive guidelines for considering a patient atopic, and criteria for diagnosing atopic dermatitis (AD) have varied from author to author. Larger case-series published from the 1960s to the 1980s suggested that the most common clinical manifestation of AD was pruritus, particularly of the face, ears, paws, extremities, and/or ventrum. It is not always clear that testing to eliminate other differential diagnoses was always carefully performed on patients in early reports; therefore, some descriptions could include patients affected with diseases other than or in addition to AD. Points of consensus regarding clinical manifestations of AD in case-series include the presence of pruritus beginning at a young age, possibly seasonally; and a prominent lesional involvement of the face, extremities, axillae or ventrum. Conflicting information on breed and sex predispositions is present, perhaps representing regional or temporal variability. Clinical reports vary, in regard to the description of lesions seen in dogs with AD. This reflects a possible confusion with lesions of secondary complications, and highlights the fact that the existence and nature of primary lesions of canine AD are not truly known.

The clinical signs of atopic dermatitis (AD) in man and in dogs are variable, and there is no single physical or historical feature that, if present, indicates the presence of AD. The initial diagnosis of AD is made clinically with the fulfillment of a combination of criteria that are strongly associated with the disease. Several schemes have been proposed in an attempt to define uniform clinical criteria for diagnosing canine AD, but no system is perfect. Once AD is considered as a possible diagnosis, other important differential diagnoses must be methodically eliminated from consideration. As a final step, once the clinician is certain that AD is probable, "allergy" tests may be conducted to provide additional evidence to "substantiate" the diagnosis. It is important to understand that allergy testing, in whatever form, is not appropriately used early in the patient evaluation as a screening test. Rather, it should be reserved, after a firm clinical diagnosis of AD has been made, to implement allergen avoidance schemes or to select allergens to be incorporated in immunotherapy formulations.

The present study investigated IgE-reactivity to two major Japanese cedar (Cryptomeria japonica, C. japonica) pollen allergens (Cry j 1 and Cry j 2) in dogs with atopic dermatitis by use of a fluorometric ELISA. The serum samples from 27 dogs that showed IgE-sensitivity to crude C. japonica pollen allergen by ELISA were tested for specific IgE to the two major allergens. All 27 dogs had anti-Cry j 1 IgE, and 10 (37%) had anti-Cry j 2 IgE. Inhibition of binding of dog specific IgE to crude C. japonica pollen allergen was carried out by addition of Cry j 1. When serum samples containing anti-Cry j 1 IgE but no anti-Cry j 2 IgE were incubated with Cry j 1, specific IgE binding to crude C. japonica pollen allergen was almost abolished. These findings suggest that Cry j 1 is a major allergen in dogs.

The present study investigates IgE-reactivity to crude and purified mite allergens by intradermal skin test (IDST), Immunodot method, and ELISA in atopic dogs sensitive to mite allergens, as well as the allergenic cross-reactivity between Dermatophgoides (D) farinae (DF) and D. pteronyssinus (DP) in dogs by IgE-ELISA inhibition. IDST and Immunodot method for crude mite allergens were performed for atopic dogs and 16 atopic dogs showed sensitivity to mite allergens. Of the 16 dogs, all dogs had anti-DF IgE and 11 had anti-DP IgE. We measured specific IgE to purified major allergens (Der f 1, Der f 2, Der p 1, Der p 2). Of the 16 atopic dogs, six had anti-Der f 1 IgE and seven had anti-Der f 2 IgE. Similarly, of the 16 dogs, six had anti-Der p 1 IgE and seven had anti-Der p 2 IgE. However, eight dogs had no specific IgE to these mite allergens. These dogs may be sensitive to other major mite allergens except Der 1 and Der 2. In the dogs that had both anti-DF and DP IgE, IgE binding to DF was greatly inhibited by DP, and reciprocal inhibition was observed. Based on these data, it appears that there is a strong cross-reactivity between DF and DP in dogs. Similarly, a cross-reactivity between DF and DP in purified allergens was also observed. IDST and Immunodot method are useful methods for the diagnosis of atopic diseases in dogs, and ELISA is a useful method for further investigation of IgE-reactivity for the allergens.

Allergen specific immunotherapy (ASIT) is a foundation treatment for canine atopic dermatitis (CAD), though few critical studies have documented its effectiveness as a disease-modifying treatment in dogs. The mechanisms by which ASIT works in dogs have not been elucidated, although they are likely to parallel those known for humans. Current ASIT approaches in CAD focus on either subcutaneous or sublingual administration. Greater knowledge of major allergens in dogs, ideal dosage regimes and details of allergen admixture are likely to lead to better efficacy in CAD. Evaluation of biomarkers for successful therapy may also be of benefit. Potentially important advances in human medicine, that have yet to be explored in dogs, include use of modified allergen preparations such as allergoids, recombinant major allergens or allergen peptides; modification with adjuvants; or packaging of the above in virus-like particles. Co-administration of immunomodulators such as CpG oligodeoxynucleotides or specific monoclonal antibodies might direct the immune response in the desired direction while calming the "cytokine storm" of active disease. Initial trials of alternative routes of administration such as intralymphatic immunotherapy have yielded exciting results in humans, and continuing study in dogs is underway. Progress in ASIT of human food allergy may provide clues that will assist with improved diagnosis and patient management of CAD. Importantly, further study must be undertaken to clarify the conditions under which ASIT is a valuable treatment modality for dogs.

Concentrations of total serum IgE, IgA, and IgG were measured in 36 atopic and 16 parasitized dogs, and compared them with 30 healthy control dogs. IgE was measured using enzyme-linked immunosorbent assay. IgA and IgG were measured using radial immunodiffusion assays. Mean total serum immunoglobulin (Ig) E concentrations in healthy, atopic and parasitized dogs were 7.1 units (U) ml-1, 5.8 U ml-1 and 14.3 U ml-1, respectively. Mean total serum IgA concentrations in the same groups were 103.3 mg dl-1, 63.2 mg dl-1 and 67.3 mg dl-1, respectively. Mean total serum IgG concentrations were 1066 mg dl-1, 1621 mg dl-1 and 1480 mg dl-1 in the three groups. There was no significant difference in IgE concentrations between these groups of dogs. IgA levels were significantly lower in atopic and parasitized dogs compared with healthy dogs (P < or = 0.05), whereas IgG levels were significantly higher in the atopic and parasitized dogs (P < or = 0.005). These results suggest that measurement of total serum IgE would be of no benefit in the preliminary clinical investigation of a suspected atopic dog. The lower IgA and higher IgG concentrations in both atopic and parasitized dogs suggest that similar regulatory mechanisms governing immunoglobulin synthesis occur in canine allergic and parasitic disease, promoting IgG synthesis but down-regulating IgA production.

Atopic dermatitis (AD) is a common chronic relapsing pruritic skin disease of dogs for which treatment has varied over time and geographical location. Recent high quality randomized controlled trials and systematic reviews have established which drugs are likely to offer consistent benefit. The International Task Force for Canine AD currently recommends a multi-faceted approach to treat dogs with AD. Acute flares should be treated with a combination of nonirritating baths and topical glucocorticoids, once an attempt has been made to identify and remove the suspected causes of the flare. Oral glucocorticoids and antimicrobial therapy must be added when needed. In dogs with chronic AD, a combination of interventions should be considered. Again, factors that trigger flares of AD must be identified and, if possible, avoided. Currently recognized flare factors include food, flea and environmental allergens, Staphylococcus bacteria and Malassezia yeast. Skin and coat hygiene and care must be improved by bathing with nonirritating shampoos and dietary supplementation with essential fatty acids. The severity of pruritus and skin lesions can be reduced with a combination of anti-inflammatory drugs. Currently, medications with good evidence of high efficacy include topical and oral glucocorticoids, and calcineurin inhibitors such as oral ciclosporin and topical tacrolimus. The dose and frequency of administration of these drugs should be tailored to each patient considering each drug's efficacy, adverse effects and cost. Allergen-specific immunotherapy should be offered, whenever feasible, in an attempt to prevent recurrence of clinical signs upon further exposure to environmental allergens to which the patient is hypersensitive.

Staphylococcal skin infection (pyoderma) is a common clinical problem in dogs. The infection can be either superficial or deep. Most cases of staphylococcal pyoderma occur secondary to a definable underlying cause. Treatment consists of finding the underlying cause and correcting it, if possible, and treating the pyoderma with antibiotics. Antibacterial shampoos may be used as adjunct treatment, but corticosteroid drugs should not be used. When canine pyoderma recurs in the absence of an identifiable underlying cause, several treatment strategies can be effective in eliminating recurrence or limiting its severity. Frequent antibacterial shampoos are an easy and sometimes effective method. Immunomodulatory drugs are variably effective. Some commercially available bacterins are clearly helpful in treating recurrent pyoderma. As a last resort, the clinician may opt to keep the patient on long-term antibiotic therapy. Such therapy may promote development and dissemination of resistant strains of Staphylococcus and should be used only if absolutely necessary.

Dermatophytosis is a relatively common disease in many countries occurring endemically both in companion and food animals. Fungi belonging to the genera Trichophyton and Microsporum are most often isolated from clinical cases. Measures to control and prevent dermatophytosis include sanitation, hygienic measures and treatment. In some countries, successful control and eradication have been achieved by mass vaccination of cattle and fur-bearing animals. Vaccines containing live attenuated cells of the fungus stimulate a cell-mediated immune response conferring long-lasting protection against subsequent challenge by the homologous fungus. A delayed type hypersensitivity (DTH) skin test using appropriate dermatophyte antigens is suitable to assess the response. Inactivated dermatophyte vaccines are available for use in cattle, horse, dog, and cat in some countries. However, the scientific literature is scarce making it difficult to conclude on efficacy and appropriate use. Current vaccines are all first generation vaccines. Attempts have been made to prepare subunit vaccines based on new knowledge about virulence factors like the keratinases, so far with limited success. Candidate antigens must be able to stimulate a strong T helper 1 cell response and future research should focus on identification of major T-cell epitopes that specifically elicit a DTH reaction. Dermatophytosis is a zoonotic disease. In Norway and a few other countries, systematic vaccination against cattle ringworm has almost eliminated the disease, and ringworm in man caused by T. verrucosum is almost nonexistent. A similar benefit could be expected if a safe and efficacious vaccine was available for Microsporum canis infection in cats and dogs.

We conducted an epidemiological study of Staphylococcus intermedius using arbitrarily primed PCR (AP-PCR) and antibiograms. One hundred and twenty-five S. intermedius isolates were recovered from the oral cavity and/or cranial hair coat of healthy dogs enrolled in a pet therapy program. Commensal S. intermedius was cultured from 32% of the oral cavity cultures and 13% of the cranial hair coat cultures. We characterized the colonization of the dogs as transient, intermittent, or persistent. For dogs characterized as persistently colonized, 73% of the isolates came from the oral cavity. These isolates were also genotyped by AP-PCR. A single major AP-PCR type was observed in 91% of the dogs (n = 22); minor variations were frequently observed in these major types. Antibiograms of these commensal isolates were compared to antibiograms from 97 historical clinical isolates (1988–1992) obtained from cases of canine pyoderma. Resistance was most often observed to penicillin (64% and 55%) and tetracycline (38% and 38%) among the commensal and clinical isolates, respectively. The commensal isolates were significantly less resistant to erythromycin, clarithromycin, clindamycin, and trimethoprim/sulfamethoxazole. Our data suggests that differences in both genotype and antimicrobial susceptibility phenotypes exist among S. intermedius strains isolated from different anatomic sites from the same dog and supports the opportunistic nature of S. intermedius in canine infections.

Allergic reactions after vaccination are considered as an important practical problem in dogs; however, their immunological mechanism has not been well understood. The present study was designed to investigate the relationship between IgE reactivity to the vaccines and immediate-type allergic reactions after vaccination in dogs. Sera from 10 dogs that developed immediate-type allergic reactions such as circulatory collapse, cyanosis, dyspnea, facial edema, and vomiting within 1h after vaccination with non-rabies monovalent or combined vaccines and sera from 50 dogs that did not develop allergic reactions after vaccination were collected. Serum IgE reactivity to the injected vaccines was measured by fluorometric ELISA using a mouse monoclonal anti-dog IgE antibody. Then, IgE reactivity to fetal calf serum (FCS) and stabilizer proteins (gelatin, casein, and peptone) included in the vaccines was measured in sera that had high levels of IgE to the vaccines. Levels of serum specific IgE to the vaccines in dogs with immediate-type allergic reactions (59-4173 fluorescence units [FU], mean +/- S.D.: 992.5 +/- 1181.9 FU) were significantly higher than those in control dogs (38-192 FU, 92.4 +/- 43.3 FU) (P < 0.001). Of the eight dogs that developed immediate-type allergic reactions and had high levels of serum specific IgE to the vaccines, seven had specific IgE directed to FCS. The IgE reactivity to the vaccines in sera from these dogs was almost completely inhibited by FCS. The other one dog had serum IgE directed to gelatin and casein included in the vaccine as stabilizers. The results obtained in this study suggest that immediate-type allergic reactions after vaccination in dogs were induced by type I hypersensitivity mediated by IgE directed to vaccine components. In addition, FCS, gelatin, and casein included in vaccines could be the causative allergens that induced immediate-type allergic reactions after vaccination in dogs.

Objective—To determine the functionality of canine anti- Malassezia IgE via the passive transfer of immediate hypersensitivity localized to the skin (ie, cutaneous anaphylaxis) from atopic dogs with dermatitis attributable to overgrowth of Malassezia pachydermatis ( Malassezia dermatitis [MD]) to healthy recipient dogs by use of the Prausnitz-Küstner (P-K) technique. Animals—7 clinically normal dogs, 32 atopic dogs with MD, serum from 11 atopic dogs with MD, and 3 healthy dogs without prior sensitization to M pachydermatis. Procedure—Serum from atopic dogs with MD was used for P-K tests in 3 clinically normal recipient dogs. Serial dilutions of untreated, heat-inactivated, IgE-absorbed, and bovine serum albumin (BSA)- absorbed (control) aliquots of serum were injected ID in triplicate for dermal sensitization. Twenty-four, 48, and 72 hours later, a crude extract of M pachydermatis was injected ID into the sites used for sensitization injections, and immediate hypersensitivity reactions were graded on a 4-point scale. Results—Untreated serum caused P-K reactivity beginning 24 hours after passive sensitization and persisting through 72 hours (titers, 1:32 to 1:64). Heat inactivation and IgE-absorption of serum eliminated P-K reactivity, whereas treatment of serum with BSA did not. Conclusions and Clinical Relevance—Analysis of P-K test results supports the passive transfer of cutaneous anaphylaxis by anti-Malassezia IgE and indicates it is functional in type-1 hypersensitivity reactions of atopic dogs with MD. Reduction or blockade of anti-Malassezia IgE in atopic dogs with MD may provide better clinical control of the disease. (Am J Vet Res 2003;64:262–266)

Objective—To determine the effect of vaccination on serum concentrations of total and antigen-specific IgE in dogs.Animals—20 female Beagles.Procedure—Groups of 5 dogs each were vaccinated repeatedly between 8 weeks and 4 years of age with a multivalent and rabies vaccine, a multivalent vaccine only, or a rabies vaccine only. A fourth group of 5 dogs served as unvaccinated controls. Serum concentrations of total immunoglobulins and antigen-specific IgE were determined following vaccination.Results—The multivalent vaccine had little effect on serum total IgE concentrations. The concentration of IgE increased slightly following vaccination for rabies at 16 weeks and 1 year of age and increased greatly after vaccination at 2 and 3 years of age in most dogs, with a distinct variation between individual dogs. Vaccination had no effect on serum concentrations of IgA, IgG, and IgM as measured at 2 and 3 years of age. The rabies vaccine contained aluminum adjuvant in contrast to the multivalent vaccine. An increase of IgE that was reactive with vaccine antigens, including bovine serum albumin and bovine fibronectin, was detected in some of the dogs vaccinated for rabies. There was no significant correlation between serum concentrations of total IgE and antigen-specific IgE following vaccination. Serum total IgE concentration rapidly returned to preimmunization concentrations in most dogs, but high concentrations of antigenspecific IgE persisted.Conclusions and Clinical Relevance—Vaccination of dogs for rabies increases serum concentrations of total IgE and induces IgE specific for vaccine antigens, including tissue culture residues. Vaccination history should be considered in the interpretation of serum total IgE concentrations. (Am J Vet Res2002;63:611–616)

Objective—To determine the efficacy of triamcinolone acetonide topical solution (TTS) in dogs for use in reduction of clinical signs of pruritic inflammatory skin diseases of a known or suspected allergic basis and to evaluate adverse effects associated with TTS administration. Animals—103 pruritic adult dogs with known or suspected allergic skin disease. Procedure—Dogs were treated for 4 weeks with TTS or with vehicle solution (control dogs) in a multiplecenter study. Clinical signs were scored by owners and by examining veterinarians before and after treatment. Blood samples obtained before and after treatment were subjected to routine hematologic and serum biochemical analyses. Results—Treatment success, as defined by an improvement of at least 2 of 6 grades in overall clinical score, was evident in 35 of 52 (67%) TTStreated dogs (mean improvement, 1.98) and 12 of 51 (24%) control dogs (mean improvement, 0.29). For several criteria, TTS was significantly more effective than vehicle in reducing clinical signs. Minor alterations in hematologic determinations in TTS-treated dogs were limited to slightly lower total leukocyte, lymphocyte, and eosinophil counts after treatment. Minor adverse effects were reported by owners in 6 of 52 (12%) TTS-treated and 9 of 51 (18%) control dogs. Conclusions and Clinical Relevance—Triamcinolone used as a spray solution at a concentration approximately one-sixth the concentration of triamcinolone topical preparations currently available for veterinary use is effective for short-term alleviation of allergic pruritus in dogs. Adverse effects are few and mild and, thus, do not preclude prolonged treatment with the solution. (Am J Vet Res 2002;63:408–413)

Three dogs were examined because of episodes of recurrent pruritic dermatitis in the spring, the season of Japanese cedar (Cryptomeria japonica, CJ) pollination in Japan. The dogs were shown to be sensitive to CJ pollen allergen using intradermal testing and antigen-specific IgE measurement. Fluorometric enzyme-linked immunosorbant assay (ELISA) showed increased concentrations of IgE specific to Cry j 1 and a negative result for Cry j 2 in the three dogs. The concentrations of IgE specific to Cry j 1 during the season of CJ pollination were higher than the concentrations found during the off-season in all the dogs, and the variation in the concentrations correlated with the variation in clinical signs. Peripheral blood mononuclear cells showed apparent proliferative responses to crude CJ pollen antigen and Cry j 1 during CJ pollination season. These findings indicated that Cry j 1 was the major allergen recognized by IgE and lymphocytes and resulted in the development of type I hypersensitivity to CJ pollen allergen in these atopic dogs.

The natural occurrence of Japanese cedar (Cryptomeria japonica) pollinosis has been reported in dogs with atopic dermatitis. However, the reactivity to Japanese cypress (Chamaecyparis obtusa) pollen allergens in these dogs has not been reported. The present study was designed to investigate the reactivity to Japanese cypress pollen allergens in dogs sensitized to Japanese cedar pollen allergens. In 19 dogs with specific IgE to C. japonica pollen allergen, we measured the specific IgE to C. obtusa pollen allergen and examined the reactivity to the allergen by intradermal test. Of the 19 dogs, 18 had specific IgE to crude and purified major allergens (Cha o 1) of C. obtusa pollen. Most of the dogs showed a positive reaction to C. obtusa pollen allergens in the intradermal test. Allergenic cross-reactivity between Cha o 1 and Cry j 1 (a major allergen in C. japonica pollen) was observed by the ELISA inhibition method. Dogs sensitized to Japanese cedar pollen allergens demonstrate reactivity to Japanese cypress pollen allergens.

Dogs and human beings with atopic dermatitis (AD) frequently exhibit concurrent skin infections with Staphylococcus sp. bacteria or Malassezia yeast, and treatment of such infections is an important facet of managing these patients. Staphylococci appear to colonize atopic skin readily, and bacterial products on the skin could augment cutaneous inflammation via immediate hypersensitivity responses to the bacteria, by superantigen-mediated lymphocyte activation, or other non-specific mechanisms. Similarly, skin colonization by Malassezia yeast could contribute to clinical signs of AD; yeast components could induce inflammation via non-specific mechanisms, such as alteration in mediator release, or via antigen-specific hypersensitivity reactions. Clinical and experimental evidence exists that secondary microbial infections can both initiate and perpetuate episodes of AD in dogs and humans, and could even participate in promotion of pro-allergic immunologic responses. Mechanistic details of these complex interactions are under extensive investigation in human beings; only a few observations have been extended to include dog with AD.

Numerous environmental allergens have been incriminated in the pathogenesis of canine atopic dermatitis (AD). These include dust and storage mite antigens, house dust, pollens from grasses, trees and weeds, mould spores, epidermal antigens, insect antigens, and miscellaneous antigens such as kapok. In this paper, we review the literature concerning the allergens that have been reported to contribute to canine AD. We conclude that attempts to identify the relevant canine antigens in the past have been plagued by a lack of standardisation of extracts and techniques, and the presence of false-positive and -negative reactions in allergy tests. Until these problems are rectified, it is unlikely that we will be able to provide a list of major and minor antigens for dogs. Hence, we recommend that future studies should be aimed at determining the major patterns of reactivity and cross-reactivity to specific protein allergens within antigenic extracts using electrophoresis and immunoblotting techniques. Once this information becomes available, it may be possible to use a selection of genetically engineered, highly pure antigens for both diagnostic and therapeutic purposes in canine allergy investigations. The use of such antigens will allow standardisation of canine allergy testing and immunotherapy so that the reliability and efficacy of these procedures can be objectively assessed.

Although an important pathogenic role for IgE is established in the case of allergic asthma and rhinitis in man, its role in atopic dermatitis is less clear. There are many studies where allergists and immunologists have provided evidence in favour of such a role, whereas dermatologists are less than convinced. In dogs, however, there is an abundance of clinical evidence implying that atopic dermatitis is antigen driven, and recent studies suggest that there may be a role for IgE, not only in the effector pathway, but also in antigen capture. Although an IgG response often accompanies an IgE response in dogs with atopic dermatitis, there is little evidence in support of a pathogenic role in respect of the former isotype.

Contamination of home-stored cereal grain food products with Dermatophagoides spp. house dust mites (HDM) was reported recently, along with anaphylaxis after consumption of these foods by dust mite-allergic people. We hypothesized that commercial dry dog food could become similarly contaminated, particularly if stored improperly, and could eventually contribute to allergic signs in dogs. Newly purchased bags of dry dog food (n = 30), from a variety of sources and manufacturers, and client samples of dry dog food (n = 50), stored under a variety of conditions, were obtained. Food samples were extracted in aqueous buffer, and extracts were assayed using ELISA for Dermatophagoides group II (Der II) allergen, as a marker for the presence of HDM. Der II allergen was not detected in any of the 30 newly purchased or 50 stored samples tested. Positive control samples consisting of house dust or dog food mixed with house dust, similarly extracted, and Dermatophagoides commercial allergen extract were positive for Der II in the same assay. We could find no evidence of HDM contamination in newly purchased or stored commercial dry dog food in the north central United States.

In our previous study [Immunology 91 (1997) 161] using monoclonal antibodies (mAbs) specific to Cry j 1, a major allergen in Japanese cedar (Cryptomeria japonica) pollen, we identified five independent epitopes (EP-1-EP-5) on the molecule and found that EP-1 and EP-5 are the predominant allergic epitopes for humans and monkeys, respectively. In this study, we analyzed the epitopes recognized by IgE in the sera of 10 dogs sensitive to C. japonica pollen allergen using an IgE-ELISA inhibition method with these mAbs. The IgE reaction patterns varied among dogs. In eight of the 10 dogs, IgE recognized EP-5 which is a predominant allergic epitope for monkeys with the pollenosis. In four dogs, IgE recognized EP-1 which is a predominant allergic epitope for human patients with the pollenosis. In three dogs, IgE recognized EP-4 which is a heat-stable epitope. EP-5 is a predominant allergic epitope for dogs and some, but not all, dogs have IgE reaction patterns to the epitopes similar to those of humans.

Using both in vivo and in vitro tests, dogs with atopic dermatitis were examined for sensitization with Japanese cedar (Cryptomeria japonica, CJ) pollen allergen. Ten dogs with clinical manifestation of atopic dermatitis were shown to be sensitized to CJ pollen based on the results of intradermal skin test and serum antigen-specific IgE test. In vitro lymphocyte stimulation test showed blastogenic response after stimulation with crude antigen of CJ pollen in all of the 5 cases examined. The peripheral leukocytes showed increased histamine release after stimulation with crude antigen of CJ pollen in 2 cases examined. These data indicate that a proportion of dogs with atopic dermatitis is sensitized to CJ pollen in a cell-mediated manner and show immediate phase reaction of type I hypersensitivity.

Eight dog IgE-specific reagents including monoclonal and polyclonal antibodies (Ab) and a cross-reactive alpha chain of the human high affinity IgE receptor were mapped to recombinant fragments of the second (IgEf2) and third/fourth (IgEf3/4) domains of the dog IgE heavy chain. In ELISA, five out of eight reagents reacted to solid-phase bound IgEf2, of which two polyclonal Ab bound in addition to IgEf3/4. All Ab which recognized at least one recombinant IgE fragment, also bound to IgE in ELISA, immunoblots, and immunohistochemistry. In contrast, only one monoclonal Ab, that did not bind to the recombinant IgE fragments, reacted with immunoblots of serum and immunohistochemistry. The alpha chain could only be applied to ELISA with serum IgE. Furthermore, there was a wide range of heat-lability of binding reactions. Comparative analysis of available dog IgE-specific reagents enables more in-depth functional studies on IgE-mediated phenomena in dogs, and helps to further establish the dog as an animal model for allergy research.

Atopic dermatitis is a common allergic disease manifestation in dogs; however, there is no correlation between clinical disease and detectable total serum IgE. Auto antibodies of the IgG subclass against IgE may affect the detection of serum IgE by immunoassay and may be important in the regulation of IgE production by B cells. ELISA were developed to detect serum antibodies specific for IgE using a newly available canine monoclonal IgE of known antigen specificity, generated from a canine x murine heterohybridoma. To test for correlation of auto IgG anti-IgE levels with manifestation of atopic dermatitis, the sera from 101 atopic dogs were compared with sera from non-atopic dogs of various breeds, foxhounds manifesting clinical signs of demodectic acariasis and helminth parasitized random bred dogs for quantities of IgG anti-IgE measured in units/ml compared to a high titer standard serum. To test for serum effects on quantitation of IgE, known amounts of canine monoclonal IgE were added to various sera and measured by capture ELISA with detecting monoclonal antibodies specific for heat labile or heat stabile epitopes. Unheated sera from dogs manifesting clinical atopic dermatitis and helminth parasitized dogs had levels of IgG anti-IgE that were significantly lower than various breeds of dogs not manifesting dermatologic lesions and foxhounds manifesting demodectic acariasis. Heating sera at 56 degrees C for 3 h to denature the high affinity binding site on the IgE heavy chain caused a marked increase over non-heated sera in detectable IgG anti-IgE in almost all dogs. This increase was most profound in helminth-infected dogs and foxhounds manifesting demodectic mange with 7 fold increases each, respectively, and in atopic dogs with a 5 fold increase compared to 3 fold increases for clinically-normal springer spaniels and all soft coated wheaten terriers. The terriers demonstrated an association of lower heated serum values of IgG anti-IgE with manifestation of a familial syndrome of protein-losing enteropathy and protein-losing nephropathy. The ability of mouse anti-canine IgE monoclonal antibodies specific for either heat labile or heat stabile epitopes to detect canine monoclonal IgE added to sera in known amounts varied from serum to serum and at different concentrations of the same serum, but did not correlate with IgG anti-IgE values for these sera. The range of absolute levels of serum IgE in dogs showing little or no inhibition of detection of added IgE was < 0.5 ng/micromilligram to 2 micrograms/micromilligram. It was concluded that the increase in detectable IgG anti-IgE after heating sera indicates that IgG x IgE immune complexes are normally present in most dogs; however, the increase over uncomplexed IgG anti-IgE was most pronounced in dogs manifesting atopic dermatitis and demodectic acariasis. A quantitative comparison of IgG anti-IgE or IgG x IgE to total serum IgE was not made because the ability of monoclonal antibodies specific for either heat labile or heat stable epitopes on the IgE heavy chain to detect IgE added to serum, as well as innate serum IgE, was highly variable in different dilutions of serum from individual to individual.

To characterize the relation between bronchoalveolar and blood eosinophil numbers, serum total IgE concentration, and nonspecific airway reactivity in healthy dogs.26 healthy Beagles.Prior to measurement of nonspecific airway responsiveness, dogs were anesthetized and bronchoscopy was performed to recover bronchoalveolar lavage (BAL) fluid. Repeated measurements were made in 6 dogs.The percentage of blood eosinophils varied between 0 and 13 (mean +/- SD, 5.6 +/- 3.6) %, the percentage of eosinophils in BAL fluid ranged between 0 and 63.5 (8.8 +/- 12.9) %, and total serum IgE concentration was 0.1 to 107.5 (23.4 +/- 29.1) U/ml. A strong association was evident between numbers of blood eosinophils and total serum IgE concentration (R2 = 0.413, P0.001), and a trend toward an association between numbers of blood eosinophils and numbers of eosinophils in BAL fluid was apparent (R2 = 0.110, P0.053). Significant associations were not found between any other aspects of the blood and BAL fluid cell profiles and total serum IgE concentration or airway reactivity. Serum total IgE concentration was not associated with airway reactivity. Further, in dogs examined on repeated occasions, variation in BAL fluid eosinophil numbers was not associated with any change in serum total IgE concentration or airway reactivity.Neither numbers of bronchoalveolar or blood eosinophils nor serum total IgE concentration have a significant role in determining airway reactivity in health dogs.

Staphylococcal antigens and immune complexes (IC) prepared from antigen and hyperimmune canine serum were tested for their effects on certain functions of mononuclear (MN) and polymorphonuclear (PMN) leukocytes (cells) obtained from healthy dogs. The effect on MN cells was studied by determining the ability of antigen or IC to augment or inhibit mitogenesis induced by phytohemagglutinin (PHA). The effect of antigen or IC on PMN cells was studied by measurement of H2O2 production as an indicator of respiratory burst. Neither the antigen nor the IC, when cultured with MN cells, was mitogenic. Coincubation of antigen or IC with MN cells and PHA resulted in a concentration-dependent decrease in mitogenesis. The decreased mitogenesis could not be overcome by addition of excess PHA, and may in part have been related to toxic effects of the antigen or IC on MN cells. When MN cells were instead preincubated with antigen or IC, then washed and stimulated with PHA, there was still a concentration-dependent inhibition of mitogenesis, although toxicity to the cells was not observed. Low concentrations of staphylococcal antigen or IC stimulated slight H2O2 production by PMN cells. When PMN cells were coincubated with IC and another stimulus (opsonized zymosan or phorbol myristate acetate), IC appeared to augment phorbol myristate acetate-, but not zymosan-induced stimulation. These results suggest that staphylococcal antigens, either alone or complexed with antibody, have the ability to stimulate PMN cells and inhibit MN cell function. Such actions may have a role in the pathogenesis of recurrent staphylococcal infection in canine patients.

A method for quantification of serum total IgE concentration in dogs by use of an ELISA containing monoclonal mouse anti-canine IgE was developed. Microtitration plates were coated with monoclonal mouse anti-canine IgE. Test sera and reference serum dilutions were added, followed by biotinylated monoclonal mouse anti-canine IgE. Avidin-alkaline phosphatase conjugate was added, and color development was measured spectrophotometrically, using a microtitration plate reader. Quantitative results were obtained by assigning to a reference serum a value of 100 IgE units/ml. Absorbance values of unknown samples were converted into IgE units by comparison with a standard curve generated by measurement of reference serum dilutions. Intra- and interassay coefficients of variation were 5 and 7%, respectively, and assay sensitivity was 1 U/ml. The assay was used to establish a normal range for total IgE concentrations in 30 healthy dogs. Total IgE concentration in healthy dogs followed a skewed distribution and ranged from1 to 91.2 U/ml, with a geometric mean value of 7.1 U/ml. The IgE concentration was remarkably stable in serum samples subjected to 25 freeze/thaw cycles or incubation at approximately 25 C (room temperature) for up to 10 days. Comparison of total IgE concentrations in 23 serum samples assayed by use of double-overlay radial immunodiffusion and ELISA yielded correlation coefficient of 0.94. Comparison of the reference serum standard curve with serial dilutions of a purified IgE solution of known concentration yielded a range of values for the IgE unit of 0.7 to 2.0 micrograms.

Immediate-type hypersensitivity reactions have been studied infrequently in dogs, in part because of limited availability of antisera specific for canine IgE. A series of murine hybridoma cell lines were prepared, that produced monoclonal antibodies (MAb) with specificity for canine immunoglobulin E (IgE) and IgG. The MAb were tested for their ability to induce a reverse cutaneous anaphylaxis reaction in dog skin, to neutralize the Prausnitz-Kustner reactivity of atopic dog serum, to serve as a ligand in immunoaffinity chromatography, and to bind to IgE and other Ig subclasses in several ELISA systems. Some of the MAb produced were found to be specific for canine IgE. Other MAb recognized common or similar determinants on IgE and IgG, or on IgG and IgM, though with apparently differing affinities. Heat or acid treatment of canine IgE abolished most, but not all, of the reactivity with the anti-IgE MAb. These MAb will be useful for further study of IgE-mediated phenomena in the dog.

Twenty-nine pruritic, atopic dogs were entered into a double-blind, placebo-controlled, crossover study to evaluate the efficacy of an investigational antiallergenic compound, AHR-13268. Fourteen dogs were evaluated by a veterinary dermatologist (at intervals) and the owner (daily). Fifteen dogs were evaluated only by the owner. The mean (+/- SE) owner scores for pruritus, erythema, and lesions with placebo treatment (higher score = worse signs) were 3.24 (+/- 0.12), 2.73 (+/- 0.12), and 2.61 (+/- 0.09), respectively. With drug treatment, the corresponding scores were 2.89 (+/- 0.12), 2.50 (+/- 0.12), and 2.25 (+/- 0.09). Scores for pruritus and lesions (but not erythema) were significantly better with drug treatment than with placebo treatment. Investigator scores showed similar trends, but the differences were not great enough to be statistically significant. Overall, 11/29 (38%) owners reported their dogs had moderate or better improvement from drug capsules, and 4/29 dogs (14%) improved on placebo capsules. A variety of adverse effects were reported following both drug (9/29 dogs) and placebo (8/29 dogs) capsule administration, but were mild and well tolerated. Results of this study indicate that AHR-13268 has potential for empiric treatment of allergic inhalant dermatitis in some dogs.

Twenty-one dogs with idiopathic superficial recurrent pyoderma were entered into a double-blind, placebo-controlled study to evaluate the efficacy of a commercial staphylococcal bacterin. The study spanned an 18-week period. All dogs were administered sodium oxacillin orally for the initial 6 weeks of the study. Dogs were given the bacterin or placebo SC, twice weekly at 3- or 4-day intervals, beginning at week 0 and continuing for 18 weeks. Dogs given antibiotics plus the bacterin (n = 13) had a significantly (P less than 0.05) better treatment response than those given antibiotic plus placebo.

The syndrome of canine juvenile cellulitis was observed and characterized throughout its clinical course when it occurred spontaneously in a litter of dogs. Histologically, pyogranulomatous inflammation was seen in facial skin and mandibular and superficial cervical lymph nodes of affected dogs. The predominant inflammatory cell characterized by light and electron microscopy and by immunohistochemical staining was an epithelioid macrophage. The same pyogranulomatous inflammatory process was seen in a lymph node anatomically distant from the site of apparent disease. Interestingly, a littermate with neither clinically evident dermal lesions nor lymphadenopathy had histologic evidence of a milder, but similar inflammatory process in a mandibular lymph node. The observation of canine juvenile cellulitis in clusters of dogs between 1 and 4 months of age and its apparent systemic nature suggest an infectious etiology. Bacterial, fungal, or viral agents were not isolated from affected lymph nodes. Attempts to transfer the disease by inoculation of neonatal puppies with tissue from affected dogs were also unsuccessful.

A solid-phase C1q-binding assay for detection of serum immune complexes (IC) was modified for an enzyme-linked immunosorbent antibody method. The IC values were measured in sera from 25 clinically normal dogs and 74 dogs with histologically confirmed neoplastic disease. Serum IC values were expressed in micrograms of heat-aggregated canine immunoglobulin per milliliter that would produce equivalent binding under the same assay conditions. The IC concentrations in sera from normal dogs and dogs with neoplastic disease (mean +/- SD) were 98 +/- 45 and 701 +/- 1,409 micrograms of aggregated canine immunoglobulin G equivalents/ml, respectively. Concentrations in the clinically normal group appeared to be distributed normally and clustered around the middle range of IC values. Dogs with neoplasms had IC values with an irregular distribution, and in general, more dogs had high and low concentrations of IC compared with those in the clinically normal group.