Measurement of allergen-specific IgG in serum is of limited value for the management of dogs diagnosed with cutaneous adverse food reactions.

Conflicting results have been reported in the literature in terms of the usefulness of serological testing for IgG against food allergens in dogs with cutaneous adverse food reaction (CAFR). The aim of the present study was to evaluate the suitability of a commercially available IgG ELISA for identifying food allergens in dogs, by challenging dogs with specific food ingredients, selected on the basis of IgG reactivity in serum samples. A total of 24 adult dogs with CAFR were enrolled into the study and 16 healthy dogs were included as a control group. Blood samples were obtained for measurement of specific IgG antibodies against 39 commonly used pet food ingredients by ELISA. Participating owners were surveyed to obtain information on their pet's dietary history. Eleven healthy control dogs and 12 dogs with CAFR were subsequently challenged in a blinded cross-over design experiment with both positive and negative food ingredients, selected on the basis of the ELISA test results. There was substantial individual variation in ELISA test results to the various food allergens, but no significant difference in IgG reactivity comparing the CAFR and control groups. None of the control dogs developed any clinical signs of an allergic reaction during the dietary challenge study. In the CAFR group, six of 12 dogs developed clinical signs after the negative challenge, and two of nine dogs developed clinical signs after the positive challenge. It was concluded that the ELISA test for dietary allergen-specific IgG is of limited value in the management of dogs with CAFR.

Dermatophagoides farinae-specific immunotherapy in atopic dogs with hypersensitivity to multiple allergens: a randomised, double blind, placebo-controlled study.

A randomised, placebo-controlled, double blind study was conducted on 25 dogs that had atopic dermatitis, together with skin test reactivity and elevated serum IgE to Dermatophagoides farinae (Df) and at least one additional allergen. Dogs were treated with either a Df-restricted immunotherapy solution (n=14) or a placebo (n=11) and evaluated 6 weeks and 3, 5, 7 and 9 months after the initiation of treatment using a clinical scoring system (SASSAD) and pruritus analogue scale scores. The Df-restricted solution and the placebo had an equal effect on both pruritus and the skin manifestations (P>0.05). The results of this study indicate that in dogs with atopic dermatitis based on hypersensitivity to environmental allergens in addition to D. farinae, Df-restricted immunotherapy is insufficient to control the disease. Consequently, a solution for allergen-specific immunotherapy should remain customised.

[Recurrent skin problems in a manatee: the diagnostic approach]. / Recidiverende huidproblemen bij een zeekoe: de diagnostische aanpak.

A 40-year-old manatee was referred with recurrent vesicular and ulcerative dermatosis for the past 15 years. During this period the animal was anorectic and lost weight. Differential diagnoses were formulated on the basis of the history and clinical signs. Skin scrapings, bacterial and fungal culture, cytological examination, blood examination, and histopathological examination of skin biopsies narrowed this list down to autoimmune dermatosis. Despite corticosteroid therapy the symptoms recurred and the animal died. Histopathological examination of post-mortem skin biopsies showed again autoimmune dermatosis, more specifically subepidermal bullous autoimmune dermatosis, as the most probable cause of the skin lesions. Post-mortem examination showed cardiac decompensation and chronic nephritis. It was impossible to estimate the possible contribution of the chronic dermatosis to the cause of death. The purpose of this case report is to show the importance of a systematic work-up of disease in exotic animals.

Immune dysregulation in atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease in humans and dogs with comparable clinical features. Comparative studies of immunological events in the pathogenesis of AD may contribute to understanding of the disease in dogs and to development and evaluation of immunomodulatory strategies of relevance to both species.Both allergen-specific as well as non-specific mechanisms contribute to the disease development. AD skin lesions are proposed to be initiated by activation of allergen-specific Th2-type cells, potentially influenced by local cutaneous factors. In the chronic stage of skin lesions reactivity may change into a Th1-type, e.g. driven by eosinophil derived IL-12. Analyses of these processes in course of time were performed in both spontaneous as well as in experimentally induced lesions (i.e. atopy patch test (APT) lesions). In the present paper, the immunological events as reported for human and canine AD are summarized and compared.

A case of Ehlers-Danlos-like syndrome in a rabbit with a review of the disease in other species.

A case of marked skin fragility in a 4-month-old pet rabbit is described. The clinical findings, gross pathology, histopathology, and ultrastructure of skin samples were consistent with Ehlers-Danlos-like syndrome. This syndrome is recognized in many animal species and is often compared to Ehlers-Danlos syndrome in humans. Ehlers-Danlos-like syndromes in animals are reviewed and possible similarities between these disorders and Ehlers-Danlos syndrome in humans are discussed.

Immunophenotyping of skin-infiltrating T-cell subsets in dogs with atopic dermatitis.

Atopic dermatitis in dogs has many clinical features that are identical to those of the same disorder in man. To investigate the pathogenesis of this disease in dogs and the possibility of similarities to the pathogenesis in humans we compared the presence and ratio of CD4+ and CD8+ T-cells in the cutaneous infiltrate of lesional and non-lesional skin of atopic dogs with that in the skin of healthy dogs. In ten dogs with atopic dermatitis and ten healthy dogs the skin was biopsied at the predilection sites for atopic dermatitis and histological sections were immunohistochemically stained for CD4 and CD8. The staining showed an increase in CD4+ and CD8+ T-cells in canine lesional atopic skin, with a predominance of CD4+ T-cells in the epidermis. In non-lesional atopic skin there was also an infiltration with CD4+ and CD8+ T-cells, but without predominance of CD4+ T-cells. The results in the separate predilection sites did not differ substantially from the mean results. These observations indicate further similarities in the immunopathogenesis of atopic dermatitis in dogs and humans, which may have consequences for the control of atopic dermatitis in dogs and contributes to a possible role of the dog as a model for human atopic dermatitis.

The expression of transferrin receptors on erythroblasts in anaemia of chronic disease, myelodysplastic syndromes and iron deficiency.

The presence of transferrin receptors on erythroblasts in patients with iron deficiency, anaemia of chronic disease (ACD) and myelodysplastic syndrome (MDS) was studied by two-colour analysis on a flow cytometer. CD 71 was used to quantify the number of transferrin receptors and GLY-A to identify erythroblasts. In cases of iron deficiency, the number of transferrin receptors was increased on part of the erythroblasts thus facilitating iron uptake by the cells. In patients with ACD or MDS, a decrease of the number of transferrin receptors on erythroblasts was found. This leads to the conclusion that the ineffective response to iron therapy in cases of ACD and MSD can be explained by a decline of transferrin receptors on the red cells.

Endocytosis and breakdown of 125I-labelled lactate dehydrogenase isoenzyme M4 by rat liver and spleen in vivo.

1. Porcine lactate dehydrogenase isoenzyme M4 was labelled with 125I and injected intravenously into rats. Enzyme activity and radioactivity in plasma were cleared in an identical way with a half-life of about 30 min. This half-life was the same as that of unlabelled enzyme. 2. Uptake of label by liver and spleen was determined. Radioactivity in these tissues increased up to about 13 min after injection and subsequently declined. Radioautography indicated uptake of the enzyme by sinusoidal liver cells (probably Kupffer cells) and by spleen macrophages. After differential fractionation of liver, acid-precipitable radioactivity was largely found in the light mitochondrial and microsomal fractions, suggesting localization in lysosomes and endosomes respectively. 3. The amount of acid-soluble radioactive breakdown products in plasma started to rise between 7 and 15 min after injection. Breakdown in liver and spleen was retarded by previous injection of suramin, an inhibitor of lysosomal proteolysis. 4. The contribution of liver and spleen towards the clearance of the enzyme could be calculated from its half-life in plasma and its uptake by the organs within the first 13 min period after injection. Our results indicate that about 65% and 12% of the injected dose was taken up, and subsequently broken down, by liver and spleen respectively. 5. Unlabelled porcine lactate dehydrogenase isoenzyme H4 showed a plasma half-life of about 8 h. This isoenzyme is therefore endocytosed by liver at a much slower rate than isoenzyme M4 (if it is taken up at all).