Canine atopic dermatitis - what have we learned?

Efficacy of Allogeneic and Xenogeneic Exosomes for the Treatment of Canine Atopic Dermatitis: A Pilot Study

Canine atopic dermatitis (CAD) is a genetically predisposed inflammatory pruritic skin disease. The available treatments for CAD have several adverse effects and vary in efficacy, indicating the need for the development of improved treatments. In this study, we aimed to elucidate the therapeutic effects of allogeneic and xenogeneic exosomes on CAD. Six laboratory beagle dogs with CAD were randomly assigned to three treatment groups: control, canine exosome (cExos), or human exosome (hExos) groups. Dogs in the cExos and hExos groups were intravenously administered 1.5 mL of cExos (5 × 1010) and hExos (7.5 × 1011) solutions, respectively, while those in the control group were administered 1.5 mL of normal saline three times per week for 4 weeks. Skin lesion score and transepidermal water loss decreased in cExos and hExos groups compared with those in the control group. The exosome treatments decreased the serum levels of inflammatory cytokines (interferon-γ, interleukin-2, interleukin-4, interleukin-12, interleukin-13, and interleukin-31) but increased those of anti-inflammatory cytokines (interleukin-10 and transforming growth factor-β), indicating the immunomodulatory effect of exosomes. Skin microbiome analysis revealed that the exosome treatments alleviated skin bacterial dysbiosis. These results suggest that allogeneic and xenogeneic exosome therapy may alleviate CAD in dogs.

Distinct healthy and atopic canine gut microbiota is influenced by diet and antibiotics

The rising trend in non-communicable chronic inflammatory diseases coincides with changes in Western lifestyle. While changes in the human microbiota may play a central role in the development of chronic diseases, estimating the contribution of associated lifestyle factors remains challenging. We studied the influence of lifestyle-diet, antibiotic use, and residential environment with housing and family-on the gut microbiota of healthy and owner-reported atopic pet dogs, searching for associations between the lifestyle factors, atopy and microbiota. The results showed that atopic and healthy dogs had contrasting gut microbial composition. The gut microbiota also differed between two breeds, Labrador Retriever and Finnish Lapphund, selected for our study. Among all lifestyle factors studied, diet was most significantly associated with gut microbiota but only weakly with atopic symptoms. Thus, diet- and atopy-associated changes in the microbiota were not interrelated. Instead, the severity of symptoms was positively associated with the usage of antibiotics, which in turn was associated with the microbiota composition. Urban lifestyle was significantly associated with the increased prevalence of allergies but not with the gut microbiota. Our results from pet dogs supported previous evidence from humans, demonstrating that antibiotics, gut microbiota and atopic manifestation are interrelated. This congruence suggests that canine atopy might be a promising model for understanding the aetiology of human allergy.

Detecting common allergens in dogs with atopic dermatitis in South Korean Provinces using a serological immunoglobulin E-specific allergen test

Background and Aim:

Canine atopic dermatitis (CAD) is a hereditary susceptibility to the development of allergic symptoms in response to repeated exposure to generally innocuous substances known as “allergens.” Allergens can be plants, animals, mold, mites, or milk. At present, serological enzyme-linked immunoassay (ELISA) kits are used for immunoglobulin E (IgE)-specific allergen detection due to their simplicity and accuracy. This study aimed to detect allergens in dogs with CAD and determine how they differ according to season, breed, age, and sex using a serological test in six provinces in South Korea for 12 months. This will allow practitioners to easily understand the risk factors related to CAD.

Materials and Methods:

In this study, IgE allergen-specific ELISA kits were used. The allergens were detected in serum samples collected from different regions considering season, sex, breed, and age. Allergens were divided into the following Ten categories: 1. Dairy, yeast, and egg, 2. grains, 3. vegetables, 4. meat, 5. seafood, 6. animals, 7. mold, 8. insects, 9. mites, and 10. trees.

Results:

The percentage of allergens detected in males (54.8%) was higher than that of females (45.2%); 54.2% of allergens occurred in 3-year-old dogs or older. Moreover, regarding frequency, 65.6% of overall allergens occur during autumn; Chungcheongnam-do and Jeollabuk-do showed 20.7% and 20.9%, respectively. Additionally, among allergens categories, notable allergen occurrence was as follows: 38.3% corn; 28.7% potatoes; 22.7% duck; 24.4%,codfish; 31.2% animal wool; 95.6% Aspergillus fumigatus; 31.9% flea; 41.8% oak; and 25.0% sheep’s sorrel grass.

Conclusion:

This study showcases the frequency of 60 allergens in six provinces detected in dogs with CAD; most likely from food or the environment using serological ELISA kits. Environmental sensitizer results can be considered for humans suffering from allergies to avoid a similar environment. A large-scale study can be performed to evaluate the allergens in the state. However, neither a skin test nor feed analysis was conducted, which is a limitation of this study.

The effect of a mixed cannabidiol and cannabidiolic acid based oil on client‐owned dogs with atopic dermatitis

Background

Cannabidiol (CBD) and cannabidiolic acid (CBDA) are reported to have antinociceptive, immunomodulatory and anti‐inflammatory actions.

Objectives

To determine if CBD/CBDA is an effective therapy for canine atopic dermatitis (cAD).

Animals

Thirty‐two privately owned dogs with cAD.

Materials and methods

Prospective, randomised, double‐blinded, placebo‐controlled study. Concurrent therapies were allowed if remained unchanged. Dogs were randomly assigned to receive either 2 mg/kg of an equal mix of CBD/CBDA (n = 17) or placebo for 4 weeks. On Day (D)0, D14 and D28, Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI‐04) and pruritus Visual Analog Scale (pVAS) scores were determined by investigators and owners, respectively. Complete blood count, serum biochemistry profiles and cytokine bioassays were performed on serum collected on D0 and D28.

Results

There was no significant difference in CADESI‐04 from D0 to D14 (p  = 0.42) or D28 (p  = 0.51) in either group. pVAS scores were significantly lower for the treatment group at D14 (p  = 0.04) and D28 (p  = 0.01) and a significant change in pVAS from baseline was seen at D14 (p  = 0.04) and not D28 (p  = 0.054) between groups. There was no significant difference in serum levels of interleukin (IL)‐6, IL‐8, monocyte chemoattractant protein ‐ 1, IL‐31 or IL‐34 between groups at D0 or D28. Elevated alkaline phosphatase was observed in four of 17 treatment group dogs.

Conclusions and clinical relevance

CBD/CBDA as an adjunct therapy decreased pruritus, and not skin lesions associated with cAD in dogs.

Interleukin 10 and transforming growth factor-beta 1 plasma levels in atopic dogs before and during immunotherapy

BACKGROUND

Human studies suggest that the cytokines, interleukin 10 (IL-10) and transforming growth factor-beta 1 (TGF-ß1) may play an important role in allergen-specific immunotherapy (ASIT). However, there is little known about the function of these cytokines in atopic dogs. This study compared the plasma levels of IL-10 and TGF-ß1 in atopic and control dogs and investigated their changes during different ASIT approaches.

METHODS

A total of 54 atopic and 32 control dogs were included. Immunotherapy was performed in 30 atopic dogs. The dogs undergoing immunotherapy were allocated to four groups of different ASIT approaches (namely subcutaneous, intralymphatic, sublingual ASIT and subcutaneous ASIT with recombinant allergens). Blood samples were collected at four timepoints throughout the one year of ASIT. Canine atopic dermatitis extent and severity index, pruritus visual analogue scale and medication score were recorded at each timepoint. Commercially available ELISA kits were used to quantify IL-10 and TGF-ß1 in plasma.

RESULTS

There was no significant difference in IL-10 and TGF-ß1 between atopic and control dogs. The IL-10 levels were significantly increased in the intralymphatic group at the end of the study. No significant differences were found in the other groups for both IL-10 and TGF-ß1.

CONCLUSION

The findings of this work suggest that IL-10 and TGF-ß1 cannot be used to monitor the course of the disease during ASIT.

Factors Associated with Prescription of Antimicrobial Drugs for Dogs and Cats, United Kingdom, 2014-2016

Antimicrobial stewardship is a cornerstone of efforts to curtail antimicrobial resistance. To determine factors potentially influencing likelihood of prescribing antimicrobials for animals, we analyzed electronic health records for unwell dogs (n = 155,732 unique dogs, 281,543 consultations) and cats (n = 69,236 unique cats, 111,139 consultations) voluntarily contributed by 173 UK veterinary practices. Using multivariable mixed effects logistic regression, we found that factors associated with decreased odds of systemic antimicrobial prescription were client decisions focused on preventive health: vaccination (dogs, odds ratio [OR] 0.93, 95% CI, 0.90-0.95; cats, OR 0.92, 95% CI 0.89-0.95), insurance (dogs, OR 0.87, 95% CI 0.84-0.90; cats, OR 0.82, 95% CI 0.79-0.86), neutering of dogs (OR 0.90, 95% CI 0.88-0.92), and practices accredited by the Royal College of Veterinary Surgeons (OR 0.79, 95% 95% CI 0.68-0.92). This large multicenter companion animal study demonstrates the potential of preventive healthcare and client engagement to encourage responsible antimicrobial drug use.

Update on pathogenesis, diagnosis, and treatment of atopic dermatitis in dogs

Improved understanding of the pathogenesis of atopic dermatitis in dogs has led to more effective treatment plans, including skin barrier repair and new targeted treatments for management of allergy-associated itch and inflammation. The intent of this review article is to provide an update on the etiologic rationale behind current recommendations that emphasize a multimodal approach for the management of atopic dermatitis in dogs. Increasing knowledge of this complex disease process will help direct future treatment options.

A comparative study of subcutaneous, intralymphatic and sublingual immunotherapy for the long-term control of dogs with nonseasonal atopic dermatitis

BACKGROUND

Allergen-specific immunotherapy (ASIT) is the only causative treatment of canine atopic dermatitis (cAD). Different routes for administration of ASIT have been used; however, comparative studies are lacking.

HYPOTHESIS/OBJECTIVES

The present study compared the efficacy and safety of subcutaneous (SCIT), intralymphatic (ILIT) and sublingual (SLIT) immunotherapy.

ANIMALS

30 atopic dogs were included and allocation to three groups (SCIT, n = 8; ILIT, n = 12; SLIT, n = 10) was determined by the owners.

METHODS AND MATERIALS

ASIT was administered using routine protocols. The pruritus Visual Analog Scale (PVAS), canine atopic dermatitis extent and severity index (CADESI), concurrent medications and adverse events were recorded initially and one, three, six and 12 months later. The main outcome measure was return to a normal status, which included CADESI <12, PVAS <2.5 and medication score <10.

RESULTS

Drop-outs were distributed evenly and 23 dogs finished the study (SCIT, n = 6; ILIT, n = 10; SLIT, n = 7). Adverse reactions to treatment were rare. At the start of the study, the three groups were homogeneous with respect to clinical signs and concurrent medications. After 12 months of ASIT, the CADESI and PVAS had decreased with a stable medication score in the ILIT and SCIT groups (P < 0.05), while all three scores had increased in the SLIT group. Return to normal state was achieved in one of six (17%) dogs receiving SCIT, in six of 10 (60%) dogs receiving ILIT and in one of seven (14%) dogs receiving SLIT.

CONCLUSIONS AND CLINICAL IMPORTANCE

These findings suggest that SCIT and ILIT improved clinical signs of cAD, whereas ILIT had a much higher return to normal rate.

Impact of the early-life skin microbiota on the development of canine atopic dermatitis in a high-risk breed birth cohort

Canine atopic dermatitis (CAD) is a prevalent inflammatory skin disease of dogs worldwide. Certain breeds such as the West Highland White Terriers (WHWT) are predisposed to suffer from CAD. Microbial dysbiosis is known to play a significant role in the pathogenesis of the disease, which is similar to its human counterpart, atopic dermatitis (AD). To date, no large cohort-study has been conducted in a predisposed dog breed to study the impact of the early-life microbiota on the development of CAD, as well as the possible implication of factors such as hygiene and access to the outdoors. In this study skin samples of 143 WHWT, including 109 puppies up to three weeks old and 34 parent dogs, from 17 breeders, were subjected to 16S rRNA gene and ITS2 amplicon sequencing to disclose the bacterial and fungal oral and skin microbiota, respectively. The oral samples served as a control group to confirm differences between haired and mucosal surfaces. The cutaneous microbiota differed between sample sites and age of the dogs. The season of sampling, geographical origin as well as hygiene status of the household and the access to the outdoors shaped the skin microbiota of the puppies significantly. However, we found that the individual early-life microbiota did not predispose for the later development of CAD.

Multidose intramuscular allogeneic adipose stem cells decrease the severity of canine atopic dermatitis: A pilot study

Aim

The aim of this pilot study was to evaluate the therapeutic and safety performance of an intramuscular treatment protocol of multidose of allogeneic adipose stem cells (ASCs) isolated, characterized, and expanded ex vivo from a healthy canine donor.

Materials and Methods

Twelve dogs diagnosed with canine atopic dermatitis (CAD) were intramuscularly treated with 0.5×10⁶ of cryopreserved ASCs from a healthy immunized young canine Ehrlichia canis free donor weekly for 6 weeks. Treatment efficacy was evaluated by the pruritus index and the CAD Lesion Index (CADLI) test. Safety and adverse effects were determined by injection site reaction, weight, blood chemistry, liver function, and whole blood count.

Results

Canine ASCs obtained from a donor met the minimum qualities required for this type of cells and showed viability of 90% after thawing. The efficacy of the CADLI score and the pruritus index in 12 dogs with atopic dermatitis was statistically significant efficacy. No adverse reactions were observed at the intramuscular application site, or in relation to animal weight, blood cell populations, or liver and renal function.

Conclusion

These results suggest that intramuscular administration of cryopreserved ASCs to dogs with atopic dermatitis is a promising cellular therapeutic product for the relief of the symptoms of this disease; however, the duration of the effects obtained with this dose and with other doses should be evaluated, as well as possible immune reactions. As far as we know, this is the first report of the use of multiple intramuscular doses cryopreserved ASCs to treat atopic dermatitis.

Measurement of serum macrophage migration inhibitory factor (MIF) and correlation with severity and pruritus scores in client owned dogs with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a common inflammatory skin disease of dogs. Macrophage migration inhibitory factor (MIF) initiates pro-inflammatory cytokine release in human AD and serum concentrations are correlated with disease severity.

HYPOTHESIS

Canine serum MIF concentrations are increased in dogs with AD and correlate with clinical lesion and pruritus scores.

ANIMALS

Client owned dogs (n = 49) diagnosed with AD and 17 healthy, unaffected control dogs were used for the study.

METHODS AND MATERIALS

A commercially available MIF ELISA was optimized for the dog and serum from clinical cases used. Information regarding treatment, Canine Atopic Dermatitis Extent and Severity Index, (CADESI-4) and pruritus Visual Analog Scale (pVAS) were recorded for each dog at the time of serum collection.

RESULTS

Dogs with AD which had not received steroid therapy and those treated with oclacitinib had significantly elevated serum MIF concentrations compared to controls. Concentrations of MIF were not significantly different in AD dogs receiving steroids compared to controls. There was no significant correlation between MIF concentrations and clinical scores (CADESI-4 or pVAS).

CONCLUSIONS AND CLINICAL IMPORTANCE

Serum MIF concentrations are increased in dogs with AD and MIF might be a target for therapy.

An open study on the efficacy of a recombinant Der f 2 (Dermatophagoides farinae) immunotherapy in atopic dogs in Hungary and Switzerland

BACKGROUND

Previously published studies evaluating a recombinant Der f 2-based immunotherapy have demonstrated efficacy in the treatment of dogs experimentally and naturally sensitized to house dust mites (HDM). Der f 2 sensitization is thought to play a minor role in European atopic dogs sensitized to HDM.

OBJECTIVE

The study evaluated the short-term efficacy of a recombinant Der f 2 product in the treatment of naturally sensitized atopic dogs in Switzerland and Hungary.

ANIMALS

Fifteen atopic dogs with positive test reactions to Dermatophagoides farinae (Df).

MATERIAL AND METHODS

Recombinant Der f 2 allergens were injected subcutaneously at increasing doses once weekly for 6 weeks. Canine Atopic Dermatitis Extent and Severity Index (CADESI-04), pruritus Visual Analog Scale (pVAS) and medication scores were assessed at days 0 and 42. Efficacy was recorded as excellent, good, fair or poor, depending on the number of scores decreasing by more than 50%.

RESULTS

Mean CADESI, pVAS and medication scores at inclusion were 35, 6 and 15 (SD = 30, 2, 7), respectively. At Day 42 the scores decreased to 8, 3 and 5, respectively (Wilcoxon matched pairs signed rank tests P = 0.0002, 0.002 and 0.001). Four dogs were classified as excellent responders with a reduction of >50% in all three scores. Nine dogs were classified as good (five) or fair (four) responders and scores deteriorated in two dogs.

CONCLUSION

These data suggest that recombinant Der f2 allergens may be as effective and show benefit faster than traditional allergen immunotherapy in European dogs sensitized to Df.

Effects in dogs with behavioural disorders of a commercial nutraceutical diet on stress and neuroendocrine parameters

The well-being of dogs can be affected by changes in human lifestyle, eating habits and increased stressors that lead to behavioural disorders including fear, hyperactivity and anxiety, followed by negative affective moods and poor welfare. This randomised, controlled clinical evaluation involved 69 dogs, 38 males and 31 females, of different breeds, with behavioural disorders related to anxiety and chronic stress. They were fed a control diet or a nutraceutical diet (ND group) for 45 days. Neuroendocrine (serotonin, dopamine, β-endorphins, noradrenaline and cortisol) and stress (derivatives of reactive oxygen metabolites (dROMs) and biological antioxidant potential (BAP)) parameters related to behavioural disorders were evaluated at the beginning and end of the study period. Results showed a significant increase in serotonin, dopamine and β-endorphins plasma concentrations (*P<0.05, *P<0.05 and **P<0.01, respectively) and a significant decrease in noradrenaline and cortisol plasma concentrations in the ND group (*P<0.05). dROMs significantly decreased in the ND group (*P<0.05) while BAP was not affected. This study demonstrated for the first time that a specific diet significantly and positively affected neuroendocrine parameters and dROMs. These results open significant perspectives concerning the use of diet and nutraceuticals in the treatment of behavioural disorders.

Confirmatory field study for the evaluation of ciclosporin at a target dose of 7.0 mg/kg (3.2 mg/lb) in the control of feline hypersensitivity dermatitis

Objectives This study was designed to confirm the efficacy and tolerability of a daily dose of 7.0 mg/kg (3.2 mg/lb) ciclosporin (CsA) in the treatment of feline hypersensitivity dermatitis (HD), as this includes some of the most frequently suspected skin diseases in cats and recent publications have reported the successful use of CsA in the treatment of feline HD. Methods In total, 217 cats with feline HD were treated daily for 42 days with a target dose of 7 mg/kg CsA (n = 144) or a placebo control (n = 73) administered either in the food or directly in the mouth following feeding. Clinical and dermatological evaluations were conducted on days 0, 21 and 42, or study exit. Safety was evaluated through physical examinations, clinical pathology and the monitoring of adverse events (AEs). Results Administration of CsA at 7.0 mg/kg produced a significant improvement in the total lesion score ( P <0.0001). The average reduction from visit 1 to visit 3 was 65.1% in the CsA group (9.2% for the placebo). In addition, owners assessed 78.3% of the cases in the CsA group as a success. Statistically significant recoveries were also seen in extent of lesions, investigator assessment of overall improvement, and mean improvement in both the investigators' and owners' assessment of pruritus. Mild gastrointestinal disorders were the most common AEs but did not require cessation of therapy. Conclusions and relevance Results confirm that 7.0 mg/kg CsA dosed daily in food or orally for up to 6 weeks is effective and well tolerated by cats with feline HD.

Evaluation of a DLA-79 allele associated with multiple immune-mediated diseases in dogs

Immune-mediated diseases are common and life-threatening disorders in dogs. Many canine immune-mediated diseases have strong breed predispositions and are believed to be inherited. However, the genetic mutations that cause these diseases are mostly unknown. As many immune-mediated diseases in humans share polymorphisms among a common set of genes, we conducted a candidate gene study of 15 of these genes across four immune-mediated diseases (immune-mediated hemolytic anemia, immune-mediated thrombocytopenia, immune-mediated polyarthritis (IMPA), and atopic dermatitis) in 195 affected and 206 unaffected dogs to assess whether causative or predictive polymorphisms might exist in similar genes in dogs. We demonstrate a strong association (Fisher's exact p = 0.0004 for allelic association, p = 0.0035 for genotypic association) between two polymorphic positions (10 bp apart) in exon 2 of one allele in DLA-79, DLA-79*001:02, and multiple immune-mediated diseases. The frequency of this allele was significantly higher in dogs with immune-mediated disease than in control dogs (0.21 vs. 0.12) and ranged from 0.28 in dogs with IMPA to 0.15 in dogs with atopic dermatitis. This allele has two non-synonymous substitutions (compared with the reference allele, DLA-79*001:01), resulting in F33L and N37D amino acid changes. These mutations occur in the peptide-binding pocket of the protein, and based upon our computational modeling studies, are likely to affect critical interactions with the peptide N-terminus. Further studies are warranted to confirm these findings more broadly and to determine the specific mechanism by which the identified variants alter canine immune system function.

IL-31-induced pruritus in dogs: a novel experimental model to evaluate anti-pruritic effects of canine therapeutics

BACKGROUND

Pruritus is a characteristic clinical sign of allergic skin conditions including atopic dermatitis (AD) in the dog. IL-31 is a cytokine found in the serum of some dogs with AD and can induce pruritic behaviours in laboratory beagle dogs.

HYPOTHESIS/OBJECTIVES

The objectives were to characterize an IL-31-induced pruritus model by evaluating the efficacy of prednisolone, dexamethasone and oclacitinib, and to compare the speed of anti-pruritic effects of oclacitinib against those of prednisolone and dexamethasone.

ANIMALS

Purpose-bred beagle dogs were used in all studies.

METHODS

Randomized, blinded, placebo-controlled studies were designed to evaluate and compare the anti-pruritic properties of prednisolone, dexamethasone and oclacitinib following a single intravenous injection of recombinant canine IL-31. Video surveillance was used to monitor and score pruritic behaviours in study animals.

RESULTS

Prednisolone [0.5 mg/kg, per os (p.o.)] reduced IL-31-induced pruritus when given 10 h prior to observation. When the time interval between drug treatment and observation was shortened to 1 h, dexamethasone (0.2 mg/kg, intramuscular) but not prednisolone (0.25 or 0.5 mg/kg, p.o.) reduced IL-31-induced pruritus. Oclacitinib (0.4 mg/kg, p.o.) reduced pruritus when given 1, 6, 11 and 16 h prior to the observation period, and the anti-pruritic activity of oclacitinib was greater when compared to prednisolone and dexamethasone at all time points assessed.

CONCLUSION AND CLINICAL IMPORTANCE

The efficacy of prednisolone, dexamethasone and oclacitinib in the IL-31-induced pruritus model gives confidence that this may be a relevant model for acute pruritus associated with allergic dermatitis including AD and can be used to evaluate novel compounds or formulations.

Efficacy of ultra-micronized palmitoylethanolamide in canine atopic dermatitis: an open-label multi-centre study

BACKGROUND

Palmitoylethanolamide is a naturally occurring bioactive lipid, produced on-demand by damage-exposed cells. Palmitoylethanolamide is documented to counteract inflammation, itch and pain.

OBJECTIVE

The aim of this 8-week study was to evaluate the efficacy of oral ultra-micronized palmitoylethanolamide (PEA-um) in dogs with moderate atopic dermatitis.

ANIMALS

Clinicians from 39 veterinary clinics enrolled 160 dogs with nonseasonal atopic dermatitis and moderate pruritus.

METHODS

This was a multi-centre open-label study. On days 0 (D0) and 56 (D56), owners evaluated pruritus with a Visual Analog Scale (VAS) and completed a validated Quality of Life (QoL) questionnaire. Veterinarians assessed the severity of skin lesions using the Canine Atopic Dermatitis Lesion Index (CADLI).

RESULTS

Mean pruritus VAS score decreased from 5.7 ± 0.08 cm (range 3.8-7.9 cm) to 3.63 ± 0.19 cm (range 0.1-9.2 cm) (P < 0.0001). At D56, 58% of dogs showed a greater than 2 cm reduction from baseline and 30% showed an absent-to-very mild pruritus (VAS ≤ 2 cm). Mean total CADLI at D56 decreased significantly (P < 0.0001); in 62% of dogs this score reached a value in the remission range (≤5). Mean total QoL score was significantly decreased (P < 0.0001) with 45% of dogs reaching QoL values described for healthy animals. Tolerability was good-to-excellent with only four dogs reporting treatment associated reversible adverse events.

CONCLUSIONS AND CLINICAL IMPORTANCE

PEA-um appears to be effective and safe in reducing pruritus and skin lesions, and in improving QoL in dogs with moderate atopic dermatitis and moderate pruritus.

Increased numbers of peripheral blood CD34+ cells in dogs with canine atopic dermatitis

BACKGROUND

The bone marrow may be involved in human atopic diseases, as shown by the release of CD34+ cells into the peripheral blood.

HYPOTHESIS/OBJECTIVES

The aim was to determine the numbers of CD34+ cells in atopic dogs.

ANIMALS

The following three groups of dogs were studied: 27 dogs with nonfood-induced atopic dermatitis (NFICAD); 16 dogs with nonallergic inflammatory diseases; and 13 healthy control dogs.

METHODS

Dogs with NFICAD were selected after fulfilment of Favrot's criteria and exclusion of other pruritic dermatoses, including flea infestation and adverse reaction to foods. The Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03 and a Visual Analog Scale (VAS) score for pruritus were used to quantify clinical signs. A phycoerythrin-conjugated anticanine CD34 antibody was used to stain peripheral blood CD34+ cells, and these were enumerated using a flow cytometer. The CD34+ cell counts were compared between groups and tested (in the NFICAD group) for correlation with the severity of clinical signs.

RESULTS

The numbers of peripheral CD34+ cells in dogs with NFICAD (median 1.7) were statistically higher than in dogs with other nonallergic inflammatory diseases (median 1.0; P = 0.01) and healthy control dogs (median 0.9; P = 0.009). In dogs with NFICAD, there was no correlation between CD34+ cell numbers and CADESI-03 scores or owner-assessed pruritus (VAS score).

CONCLUSIONS AND CLINICAL IMPORTANCE

The results of this study suggest the possible involvement of CD34+ cells in dogs with NFICAD. The role of CD34+ cells in the aetiopathogenesis of canine atopic dermatitis remains to be determined.

Sensitization rates of causative allergens for dogs with atopic dermatitis: detection of canine allergen-specific IgE

Allergen-specific IgE serology tests became commercially available in the 1980s. Since then these tests have been widely used to diagnose and treat allergic skin diseases. However, the relationship between a positive reaction and disease occurrence has been controversial. The purpose of this study was to evaluate allergens using a serologic allergy test in dogs with atopic dermatitis (AD). Dogs clinically diagnosed with AD (n = 101) were tested using an allergen-specific IgE immunoassay. Among the total 92 environmental and food allergens, house dust and house dust mites were the most common. Several allergens including airborne pollens and molds produced positive reactions, and which was considered increasing allergens relating to the climate changes. The presence of antibodies against staphylococci and Malassezia in cases of canine AD was warranted in this study. Additionally, strong (chicken, turkey, brown rice, brewer's yeast, and soybean) and weakly (rabbit, vension, duck, and tuna) positive reactions to food allergens could be used for avoidance and limited-allergen trials.

An emulsion restores the skin barrier by decreasing the skin pH and inflammation in a canine experimental model

The aim of this study was to investigate the effect of Douxo(®) Calm Mousse (Sogeval, Laval, France) on restoration of the skin barrier in a canine model of barrier disruption. Tape strips were performed, daily for 6 days, on the lateral thorax of five healthy beagle dogs. Douxo(®) Calm Mousse was applied daily for 5 days to one side of the thorax and the opposite side was left untreated. The effects of treatment were evaluated by measurement of transepidermal water loss (TEWL) and pH and by histological assessment of disrupted skin at various times during barrier repair. Although no effect on TEWL was observed, Douxo(®) Calm Mousse maintained an acidic pH after three applications and reduced skin inflammation, which was most pronounced after five applications. The results of the study suggest that Douxo(®) Calm Mousse exerts a beneficial effect on barrier restoration and on markers of inflammation.

Increased levels of palmitoylethanolamide and other bioactive lipid mediators and enhanced local mast cell proliferation in canine atopic dermatitis

BACKGROUND

Despite the precise pathogenesis of atopic dermatitis (AD) is unknown, an immune dysregulation that causes Th2-predominant inflammation and an intrinsic defect in skin barrier function are currently the two major hypotheses, according to the so-called outside-inside-outside model. Mast cells (MCs) are involved in AD both by releasing Th2 polarizing cytokines and generating pruritus symptoms through release of histamine and tryptase. A link between MCs and skin barrier defects was recently uncovered, with histamine being found to profoundly contribute to the skin barrier defects.Palmitoylethanolamide and related lipid mediators are endogenous bioactive compounds, considered to play a protective homeostatic role in many tissues: evidence collected so far shows that the anti-inflammatory effect of palmitoylethanolamide depends on the down-modulation of MC degranulation.Based on this background, the purpose of the present study was twofold: (a) to determine if the endogenous levels of palmitoylethanolamide and other bioactive lipid mediators are changed in the skin of AD dogs compared to healthy animals; (b) to examine if MC number is increased in the skin of AD dogs and, if so, whether it depends on MC in-situ proliferation.

RESULTS

The amount of lipid extract expressed as percent of biopsy tissue weight was significantly reduced in AD skin while the levels of all analyzed bioactive lipid mediators were significantly elevated, with palmitoylethanolamide showing the highest increase.In dogs with AD, the number of MCs was significantly increased in both the subepidermal and the perifollicular compartments and their granule content was significantly decreased in the latter. Also, in situ proliferation of MCs was documented.

CONCLUSIONS

The levels of palmitoylethanolamide and other bioactive lipid mediators were shown to increase in AD skin compared to healthy samples, leading to the hypothesis that they may be part of the body's innate mechanisms to maintain cellular homeostasis when faced with AD-related inflammation. In particular, the increase may be considered a temptative response to down-regulating the observed elevation in the number, functionality and proliferative state of MCs in the skin of AD dogs. Further studies are warranted to confirm the hypothesis.

IgE-based Immunotherapy of Cancer -A Comparative Oncology Approach

Antibody-based immunotherapies are important therapy options in human oncology. Although human humoral specific immunity is constituted of five different immunoglobulin classes, currently only IgG-based immunotherapies have proceeded to clinical application.

This review, however, discusses the benefits and difficulties of IgE-based immunotherapy of cancer, with special emphasis on how to translate promising preclinical results into clinical studies. Pursuing the “Comparative Oncology” approach, novel drug candidates are investigated in clinical trials with veterinary cancer patients, most often dogs. By this strategy drug development could be speeded up, animal experiments could be reduced and novel therapy options could be introduced benefitting humans as well as man’s best friend.