Determination of CADESI-03 thresholds for increasing severity levels of canine atopic dermatitis

Insect Bite Hypersensitivity in Horses: Causes, Diagnosis, Scoring and New Therapies

Insect Bite Hypersensitivity (IBH, Queensland itch, sweet itch, equine summer eczema) is the most common pruritic disease of horses. It is most often caused by sensitivity to the saliva of Culicoides spp. of biting midges; however, it can also be caused by hypersensitivity to other insect species. The prevalence of IBH in horses is reported to be as high as 60% in some parts of the world. Due to the severe pruritus and effects of secondary self-trauma, IBH has animal welfare concerns, and there is currently no cure. Management of this condition is life-long, time consuming and costly. New grading systems to document disease severity are being validated, which will allow the comparison of clinical trial results of new and existing therapies. Management involves the minimisation of insect bites by use of stabling, fans, rugs and repellents. Symptomatic therapy involves the administration of systemic or topical corticosteroids, systemic antihistamines, and creams and sprays to promote skin healing and decrease inflammation. New immune-mediated therapeutics including vaccines, in addition to desensitisation procedures, show promise at controlling hypersensitivity reactions. This article will review aetiologic agents, pathophysiology, scoring systems and current and new therapies.

Evaluation of a clinical scoring system for canine demodicosis

BACKGROUND

Canine demodicosis is a common disease in small animal practice. Although a number of studies evaluating treatment efficacy for canine demodicosis have used clinical scoring systems, none have been validated.

OBJECTIVES

This study evaluated the validity, reliability, reproducibility and sensitivity to change of a clinical scoring system for canine demodicosis.

METHODS AND MATERIALS

Fifty-eight dogs with generalised demodicosis were evaluated using a clinical scoring system that assessed erythema, comedones/ papules/pustules, follicular casts/scales/crusts and alopecia, rated from none to mild, moderate and severe in 36 body locations. Two evaluators scored lesions at monthly consecutive visits during treatment. Mites were counted to a maximum of 50 in four deep skin scrapings. With >50 mites, the approximate mite number was calculated with the help of a grid drawn onto the slide before placing the scraped material onto it.

RESULTS

A Pearson correlation coefficient showed a high interobserver reliability (r = 0.97) between two different clinicians evaluating the same dog. The Wilcoxon signed rank test showed good sensitivity to change with a reduction of clinical scores with each of the first six evaluations (P < 0.0001). A linear mixed model also showed a clear reduction in mite counts (P < 0.001) and clinical scores (P < 0.0001) from the first evaluation with time.

CONCLUSION AND CLINICAL RELEVANCE

The clinical scoring system for canine demodicosis evaluated in this study showed a good sensitivity to change and interobserver reliability, and can be used in studies evaluating canine demodicosis.

Treatment of the feline atopic syndrome - a systematic review

BACKGROUND

Feline allergic skin disease and asthma occur regularly in small animal practice.

OBJECTIVES

To provide evidence-based recommendations for small animal practitioners on the treatment of feline atopic syndrome (FAS).

METHODS AND MATERIALS

The authors reviewed the literature available before February 2020, prepared a detailed evidence-based literature review and made recommendations based on the evaluated evidence.

RESULTS

Sixty-six papers and abstracts were identified describing treatment interventions for FAS and evaluated to establish treatment recommendations. For many treatment options, the papers were retrospective, open studies or case reports.

CONCLUSION AND CLINICAL RELEVANCE

In this review, there was good evidence for the efficacy of systemic glucocorticoids and ciclosporin, and limited evidence for the efficacy of topical glucocorticoids, oclacitinib and allergen-specific immunotherapy in feline atopic skin syndrome. Evidence pointed to low-to-moderate efficacy for antihistamines, fatty acids and palmitoyl ethanolamide. In feline asthma, there was good evidence for the efficacy of oral and inhaled glucocorticoids, and limited evidence of moderate efficacy for allergen-specific immunotherapy. Evidence supported low-to-moderate efficacy of mesenchymal stem cells, inhaled lidocaine and oclacitinib as treatments for feline asthma. For almost all therapeutic options (with the exception of glucocorticoids and ciclosporin), more randomised controlled trials are needed.

Serum IgE and IgG responses to dietary antigens in dogs with and without cutaneous adverse food reactions

BACKGROUND

It is suspected that many canine cutaneous adverse food reactions (CAFR) are true immunological hypersensitivities; however, few specific dietary allergens have been identified.

OBJECTIVE

To compare serum immunoglobulin (Ig)E and IgG reactivity to specific food antigens in privately owned dogs with and without CAFR.

ANIMALS

Eighteen adult dogs with nonseasonal pruritus recruited from a hospital population.

METHODS AND MATERIALS

Dogs were fed an extensively hydrolysed poultry-based diet exclusively for 12 weeks. Serum was collected at the beginning of the trial. Canine atopic dermatitis extent and severity index and pruritus Visual Analog Scale scoring were performed at the beginning and end of the trial. Immunoblotting was performed to identify IgE and/or IgG binding to specific proteins in beef, egg, milk, chicken, pork, soy and wheat extracts.

RESULTS

A CAFR (defined as an unequivocal relapse of pruritus after dietary challenge) was diagnosed in 10 dogs, with 60% relapsing when fed chicken-based diets. Binding of subjects' IgG to almost all proteins in all extracts was seen regardless of reported dietary history. Few proteins were exclusively or predominantly bound by IgE in CAFR dogs. Exceptions included a 42 kDa band (chicken), a 52 kDa band (beef), a 46 kDa band (beef and milk) and a poorly defined high molecular weight protein or proteins (beef and milk).

CONCLUSION

This study demonstrated three protein bands and a poorly defined band predominantly recognized by sera from dogs with CAFR relative to non-CAFR dog sera. Almost all proteins were bound by IgG in all dogs, suggesting prior exposure to unreported foods.

Development of a core outcome set for therapeutic clinical trials enrolling dogs with atopic dermatitis (COSCAD'18)

BACKGROUND

For decades, the efficacy of interventions in clinical trials enrolling dogs with atopic dermatitis (AD) relied on heterogeneous evaluations of skin lesions and pruritus using unvalidated tools. Although some instruments for clinical signs were validated later, there was little impact on standardizing outcome measures resulting in difficulties in comparing treatment efficacy between trials and impeding meta-analyses.

RESULTS

Participants in the Outcome Measures subcommittee of the International Committee of Allergic Diseases of Animals (ICADA) collaborated for two years to develop a core outcome set (COS) for canine AD, the COSCAD. This project involved several steps, constantly-re-assessed during online exchanges, to define the scope of this COS, to identify the relevant stakeholders, the domains to be evaluated, the instruments available for measuring agreed-upon domains and how to express outcome measures. This COSCAD'18 was designed principally for therapeutic-but not preventive or proactive-clinical trials enrolling dogs with chronic, nonseasonal (perennial), moderate-to-severe AD. Selected domains were skin lesions, pruritus manifestations and perception of treatment efficacy. Instruments to evaluate these domains were the CADESI4 or CADLI, the 10-point pruritus visual analog scale (PVAS10) and the Owner Global Assessment of Treatment Efficacy (OGATE), respectively. The COSCAD'18 has three outcome measures: the percentages of dogs with veterinarian-assessed skin lesions or owner-rated pruritus manifestation scores in the range of normal dogs or those with mild AD; the third is a good-to-excellent global assessment by the pet owners of their perception of treatment efficacy. Importantly, this COSCAD'18 is not meant to represent the sole-or primary-outcome measures evaluated in a trial; authors are always free to add any others, which they deem will best assess the efficacy of tested interventions. Benchmarks to define a threshold for treatment success were not set, as what constitutes a clinically-relevant therapeutic efficacy is expected to vary greatly depending interventions.

CONCLUSIONS

This COSCAD'18 should help veterinarians and owners compare the benefits of treatments in future trials. This COS should also facilitate the combination of trial results in future systematic reviews, thereby producing more reliable summary estimates of treatment effects and enhancing evidence-based veterinary dermatology.

Evaluation on the effects of 0.1% Peumus boldus leaf and Spiraea ulmaria plant extract combination on bacterial colonization in canine atopic dermatitis: A preliminary randomized, placebo controlled, double-blinded study

Defective skin barrier characterize canine atopic dermatitis (AD). Pyoderma is the most common complication. Herbal compounds have been suggested as alternatives to control bacterial colonization for their effect on natural antimicrobial peptides (AMPs). This study evaluated the effects of 0.1% Peumus boldus leaf and Spiraea ulmaria plant extract combination on clinical signs, bacterial colonization and AMPs secretion in atopic dogs compared to placebo. Twenty privately-owned atopic dogs were randomly divided in 2 groups (treatment: n = 10; placebo: n = 10) and their abdomen was sprayed every 24 h for 4 weeks. Total and inguinal clinical scores (CADESI-03), manual bacterial count, and skin washes for AMPs (cBD3-like and cCath) were performed on days 0, 14 and 28. AMPs were detected using in-house, previously-validated, canine-specific ELISAs. Data were statistically analyzed and a p < 0.05 was considered significant. Clinical scores and AMPs secretion did not differ significantly between the two groups at any time point. A significant reduction of the clinical scores was seen in the placebo group at 14 and 28 days (p < 0.04). On days 14 and 28, a reduction in the bacterial count was seen in the treated group compared with placebo (p < 0.009 and p = 0.04, respectively). Compared to baseline, a reduction in Staphylococcus spp. was seen in the treated group after 14 days of treatment (p < 0.03). These results show the efficacy of this plant extract combination against bacterial colonization, suggesting its potential usefulness in preventing bacterial infection in atopic dogs. The influence of this compound on AMPs secretion or other mechanisms should be further evaluated.

A blinded, randomized clinical trial evaluating the efficacy and safety of lokivetmab compared to ciclosporin in client-owned dogs with atopic dermatitis

BACKGROUND

Lokivetmab is an injectable anti-canine-IL-31 monoclonal antibody to treat clinical manifestations of atopic dermatitis (AD) in dogs.

HYPOTHESIS/OBJECTIVES

To characterize the efficacy and safety of lokivetmab, and to demonstrate its noninferiority to ciclosporin under field conditions.

ANIMALS

Dogs with chronic AD (n = 274) were enrolled from 40 practices in Belgium, The Netherlands, France and Germany.

METHODS

Animals were randomized (1:1) to oral ciclosporin (5 mg/kg/once daily) or monthly injectable lokivetmab (1-3.3 mg/kg) for three months. Eighty one animals that successfully completed the comparative phase were enrolled in a continuation phase receiving lokivetmab for an additional six months. Owners assessed pruritus on a Visual Analog Scale, skin lesions were assessed by veterinary investigators with a Canine AD Extent and Severity Index (CADESI-03) scale.

RESULTS

Lokivetmab was noninferior to ciclosporin for pruritus reduction on Day 28 (51.90% versus 43.72%). For Day 28 CADESI-03 percentage reduction, noninferiority of lokivetmab (54.17) versus ciclosporin (56.86%) was not achieved. At none of the time points were mean CADESI-03 scores significantly different between groups. Continued efficacy towards pruritus and lesions was demonstrated in the continuation phase where 76.3% of animals (n = 45) were assessed as 'normal' for pruritus at study end. No abnormal health events associated with lokivetmab were observed during the initial three month phase (142 dogs) or during the subsequent six month phase (81 dogs).

CONCLUSIONS AND CLINICAL IMPORTANCE

Lokivetmab at a minimum monthly dose of 1 mg/kg provided quick onset (within one day) of a lasting effect in reducing pruritus and skin lesions with a good safety profile.

Retrospective Evaluation of Canine Dermatitis Secondary to Corynebacterium spp

Corynebacterium species are considered nonpathogenic in canine dermatitis; however, potential clinical significance has been demonstrated in canine otitis externa and from a dog bite wound in a human. Objectives of this study were to identify the predominant Corynebacterium species present in lesions of canine dermatitis, assess pathogenic role, determine antimicrobial susceptibility, and evaluate clinical response. Of 37 isolates identified as Corynebacterium, 31 were Corynebacterium auriscanis . Most Corynebacterium isolates were susceptible to chloramphenicol (97%), tetracyclines (92%), and amikacin (89%); isolate susceptibilities to β-lactams, trimethoprim-sulfonamides, and fluoroquinolones were <50%. Most cultures grew mixed populations of bacteria; C. auriscanis was the only organism isolated in three patients. At recheck, 2-8 wk after initial presentation, pleomorphic rods were absent or significantly decreased in all patients. Two of three C. auriscanis isolates were obtained in pure culture and were evaluable, meaning patient had an initial exam and recheck examination. Both patients were already on antimicrobials to which C. auriscanis was resistant in vitro. Both improved after doxycycline administration. C. auriscanis may act as an opportunistic pathogen in canine dermatitis and may not respond to antimicrobial therapy based on susceptibilities for other organisms in mixed infections. Occasionally, Corynebacterium isolated alone may be pathogenic.

A blinded, randomized, placebo-controlled, dose determination trial of lokivetmab (ZTS-00103289), a caninized, anti-canine IL-31 monoclonal antibody in client owned dogs with atopic dermatitis

BACKGROUND

Pruritus is the hallmark clinical sign of atopic dermatitis (AD) in dogs. Lokivetmab, a caninized anti-canine IL-31 monoclonal antibody, reduced pruritus and associated inflammatory skin lesions in a proof-of-concept study in dogs with AD.

HYPOTHESIS/OBJECTIVES

The objective was to describe lokivetmab dose response in a randomized, double blind, placebo-controlled trial.

ANIMALS

Clinicians at 15 referral clinics enrolled 211 client owned dogs with a history of chronic AD.

METHODS

Dogs were randomized to treatment with lokivetmab (0.125, 0.5 or 2.0 mg/kg) or placebo administered subcutaneously once on Day 0. Dog owners assessed visual analog scale (VAS) scores of pruritus on days 0, 1, 2, 3, 7, 14, 21, 28, 35, 42, 49 and 56. Clinicians assessed Canine AD Extent and Severity Index (CADESI-03) scores on days 0, 7, 14, 28, 42 and 56.

RESULTS

Treatment with lokivetmab (2 mg/kg) resulted in a greater percentage reduction from baseline in owner assessed pruritus (days 1-49) and clinician assessed CADESI-03 scores (days 7-56) compared to placebo (P < 0.05); differences were achieved in lower dose groups but at later time points and for shorter duration for both owner assessed pruritus (0.5 mg/kg, days 2-35; 0.125 mg/kg, days 7-21) and clinician assessed CADESI-03 scores (0.5 mg/kg and 0.125 mg/kg, Day 14).

CONCLUSIONS AND CLINICAL IMPORTANCE

Lokivetmab (0.5, 2.0 mg/kg) reduced pruritus compared to placebo for at least 1 month. Level and duration of response increased with increasing dose. Further studies are needed to better understand variability in individual responses across a broader population of dogs with AD.

A blinded, randomized, placebo-controlled trial of the efficacy and safety of the Janus kinase inhibitor oclacitinib (Apoquel®) in client-owned dogs with atopic dermatitis

Background

Pruritus is the hallmark clinical sign of atopic dermatitis (AD) in dogs. Preliminary study results suggest that oclacitinib, a selective Janus kinase inhibitor, could reduce pruritus and associated inflammatory skin lesions in dogs with AD.

Hypothesis/Objectives

The objective was to evaluate efficacy and safety of oclacitinib (Apoquel^®) for the control of AD in a randomized, double‐blind, placebo‐controlled trial.

Animals

Clinicians at 18 specialty clinics enrolled client‐owned dogs (n = 299) with a history of chronic AD.

Methods

Dogs were randomized to receive either oclacitinib (0.4–0.6 mg/kg twice daily for 14 days and then once daily for up to 112 days) or an excipient‐matched placebo. Owners assessed visual analog scale (VAS) scores of pruritus on days 0, 1, 2, 7, 14, 28, 56, 84 and 112. Clinicians assessed Canine AD Extent and Severity Index (CADESI‐02) scores on days 0, 14, 28, 56, 84 and 112.

Results

On days 1, 2, 7, 14 and 28, oclacitinib‐treated dogs had a 29.5, 42.3, 61.5, 66.7 and 47.4% reduction from baseline in owner‐assessed pruritus scores, respectively, compared with a 6.5, 9.1, 6.5, 3.9 and 10.4% reduction in placebo‐treated dogs. On days 14 and 28, dermatologists recorded a 48.4% reduction in CADESI‐02 scores in oclacitinib‐treated dogs compared with a 1.7% reduction and a 3.6% increase in placebo‐treated dogs. After day 28, >86% of all placebo‐treated dogs had moved to an open‐label study, making between‐group comparisons biased. Differences were significant at all time points assessed (P < 0.0001).

Conclusions and clinical importance

Oclacitinib provided rapid, effective and safe control of AD, with substantial improvement in VAS and CADESI‐02 scores.

LD-aminopterin in the canine homologue of human atopic dermatitis: a randomized, controlled trial reveals dosing factors affecting optimal therapy

Background

Options are limited for patients with atopic dermatitis (AD) who do not respond to topical treatments. Antifolate therapy with systemic methotrexate improves the disease, but is associated with adverse effects. The investigational antifolate LD-aminopterin may offer improved safety. It is not known how antifolate dose and dosing frequency affect efficacy in AD, but a primary mechanism is thought to involve the antifolate-mediated accumulation of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). However, recent in vitro studies indicate that AICAR increases then decreases as a function of antifolate concentration. To address this issue and understand how dosing affects antifolate efficacy in AD, we examined the efficacy and safety of different oral doses and schedules of LD-aminopterin in the canine model of AD.

Methods and Findings

This was a multi-center, double-blind trial involving 75 subjects with canine AD randomized to receive up to 12 weeks of placebo, once-weekly (0.007, 0.014, 0.021 mg/kg) or twice-weekly (0.007 mg/kg) LD-aminopterin. The primary efficacy outcome was the Global Score (GS), a composite of validated measures of disease severity and itch. GS improved in all once-weekly cohorts, with 0.014 mg/kg being optimal and significant (43%, P<0.01). The majority of improvement was seen by 8 weeks. In contrast, GS in the twice-weekly cohort was similar to placebo and worse than all once-weekly cohorts. Adverse events were similar across all treated cohorts and placebo.

Conclusions

Once-weekly LD-aminopterin was safe and efficacious in canine AD. Twice-weekly dosing negated efficacy despite having the same daily and weekly dose as effective once-weekly regimens. Optimal dosing in this homologue of human AD correlated with the concentration-selective accumulation of AICAR in vitro, consistent with AICAR mediating LD-aminopterin efficacy in AD.

Oral and subcutaneous therapy of canine atopic dermatitis with recombinant feline interferon omega

Canine atopic dermatitis (CAD) is a common allergic skin disease that has been treated with subcutaneously administered interferons (IFN). Recombinant feline IFN-ω (rFeIFN-ω) was reported to be efficacious for CAD. Whether dogs develop neutralizing antibodies against rFeIFN-ω during long-term treatment and whether orally administered IFNs are efficacious in CAD is unknown. The aim of this study was to evaluate the potential development of antibodies against rFeIFN-ω in atopic dogs and to compare subcutaneous and oral IFN therapy. Twenty-six atopic dogs were randomly assigned to two groups. The first group (n=15) received eight subcutaneous injections of rFeIFN-ω (Virbagen® omega, Virbac, Carros, France) over four months, the second group (n=11) received rFeIFN-ω daily orally. Concurrent medication was permitted, except systemically acting glucocorticoids and cyclosporin, which had to be withdrawn at least two weeks prior to the study. Serum samples for antibody detection were collected before and after the study. On days 0, 60 and 120 skin lesions and pruritus were evaluated using a validated lesion score (Canine Atopic Dermatitis Extent and Severity Index=CADESI) and a validated pruritus score. Concurrent medications were recorded. For every visit a total score, consisting of CADESI, pruritus score and medication score was created. For antibody detection an indirect ELISA, using Virbagen® omega as antigen, was performed. Comparison of pruritus scores, CADESI and total scores between days 0 and 120 showed improvement in both groups, however, significant improvement could only be detected in the oral group with CADESI and total scores (61%, P=0.04 and 36%, P=0.02 respectively). Serum antibodies against rFeIFN-ω could not be detected in any of the dogs. In this study antibody production could not be demonstrated. It suggests better efficacy with oral IFN administration, which should be further verified in larger, randomized, controlled studies.

Clinical use of a ceramide-based moisturizer for treating dogs with atopic dermatitis

In humans, skin barrier dysfunction is thought to be responsible for enhanced penetration of allergens. Similar to conditions seen in humans, canine atopic dermatitis (CAD) is characterized by derangement of corneocytes and disorganization of intercellular lipids in the stratum corenum (SC) with decreased ceramide levels. This study was designed to evaluate the effects of a moisturizer containing ceramide on dogs with CAD. Dogs (n = 20, 3~8 years old) with mild to moderate clinical signs were recruited and applied a moisturizer containing ceramide for 4 weeks. Transepidermal water loss (TEWL), skin hydration, pruritus index for canine atopic dermatitis (PICAD) scores, and canine atopic dermatitis extent and severity index (CADESI) scores of all dogs were evaluated. Skin samples from five dogs were also examined with transmission electron microscopy (TEM) using ruthenium tetroxide. TEWL, PICAD, and CADESI values decreased (p < 0.05) and skin hydration increased dramatically over time (p < 0.05). Electron micrographs showed that the skin barrier of all five dogs was partially restored (p < 0.05). In conclusion, these results demonstrated that moisturizer containing ceramide was effective for treating skin barrier dysfunction and CAD symptoms.

Development and validation of the Canine Atopic Dermatitis Lesion Index, a scale for the rapid scoring of lesion severity in canine atopic dermatitis

BACKGROUND

The third iteration of the Canine Atopic Dermatitis Extent and Severity Index (CADESI-03) is the only tool rigorously validated for canine atopic dermatitis (CAD) lesion scoring. The CADESI-03 requires 248 evaluations, limiting its widespread use.

HYPOTHESIS/OBJECTIVES

The goal of the study was to develop and validate a practical method of grading CAD lesions that requires scoring only the frequently affected body regions.

ANIMALS

Fifty-seven privately owned atopic dogs were used in the study.

METHODS

The Canine Atopic Dermatitis Lesion Index (CADLI) was evaluated in an open, multicentre reliability study. Validity was assessed with expert opinion (content validity) and comparison of CADLI with existing disease severity measures (construct and criterion validity). Reliability was evaluated by analysing repeated observations of each dog. Convenience was assessed in terms of the time required to complete the scale.

RESULTS

The CADLI scores correlated with overall assessment scores (r = 0.60, P < 0.001, linear mixed model) and pruritus severity scores (r = 0.53, P < 0.001, linear mixed model), establishing construct validity. The CADLI was strongly correlated with CADESI-03 (r = 0.84, P < 0.001, linear mixed model), establishing criterion validity. The CADLI values obtained by two observers correlated very strongly (r = 0.91, P < 0.001), as did the repeat values for the same observer (r = 0.98, P < 0.001). The mean time to complete the CADLI was less than that required for CADESI-03 (1.9 and 12.6 min, respectively), a highly significant difference (P < 0.001).

CONCLUSION AND CLINICAL IMPORTANCE

The CADLI was found to be an effective measure of CAD lesion severity, strongly correlating with CADESI-03. The convenience of CADLI makes it suitable for use in both clinical research and practice.

Pilot study to evaluate the effect of topical dimethicone on clinical signs and skin barrier function in dogs with naturally occurring atopic dermatitis

This study investigated the effects of a skin protectant solution (dimethicone 2%) on clinical signs and skin barrier function in canine atopic dermatitis (AD). Eighteen dogs with AD were randomly divided into two groups, one received dimethicone and the other received the vehicle (cyclomethicone) on selected areas (pinnae, groin, and axillae) daily for 4 weeks. Owners and investigators were blinded regarding group allocation. Clinical efficacy was evaluated using a scoring system and skin barrier by measuring the transepidermal water loss. Twelve dogs completed the study (50% drop rate in the vehicle and 20% in the dimethicone). For clinical signs, analysis of variance showed an effect of time (P < 0.005; day 0 > day 28) and region (axillae < groin < pinnae) but no effect of group or group × time interaction. For transepidermal water loss, analysis of variance showed only a main effect of region (axillae > pinnae > groin). Pearson found no correlation between transepidermal water loss and clinical scores. In this pilot study dimethicone had no significant effect on clinical signs and transepidermal water loss in canine atopic dermatitis.

Dose tapering for ciclosporin in cats with nonflea-induced hypersensitivity dermatitis

BACKGROUND

Little information is available on the ciclosporin dose-tapering regimen and clinical response in the treatment of feline hypersensitivity dermatitis.

HYPOTHESIS/OBJECTIVES

To test a dose-tapering regimen and assess efficacy and clinical safety for up to 18 weeks.

ANIMALS

Eighty-eight client-owned cats with feline hypersensitivity dermatitis.

METHODS

Cats that received either a placebo or ciclosporin at 2.5 mg/kg or 7 mg/kg daily for 6 weeks were given 7 mg/kg ciclosporin daily for 4 weeks. Depending on the clinical response, the dose was tapered from daily to every other day over the next 4 weeks and further to twice a week for an additional 4 weeks.

RESULTS

After all cats received 7 mg/kg for 4 weeks, the dose could be tapered to every other day for the next 4 weeks in 70% of cats remaining in the study. During the next 4 weeks, 57, 15 and 22% of cats remaining in the study could be treated at twice a week, every other day or daily, respectively. After the first 4 weeks, the mean lesion score and owner-assessed pruritus improved over baseline by 69 and 61%, respectively, and remained stable during the following 8 weeks. Approximately 65% of the cats in the study were reported to have an adverse event (AE), very often mild and resolving spontaneously. The most frequent AEs were gastrointestinal and included primarily vomiting and diarrhoea. Eighty per cent of AEs occurred when cats were on daily treatment.

CONCLUSIONS AND CLINICAL IMPORTANCE

Results suggest that the induction dose of 7 mg/kg ciclosporin can be tapered as soon as 4 weeks without deterioration of the clinical response. Establishment of the lowest effective dosing regimen of ciclosporin reduced the frequency of AEs.

Plasma and skin vitamin E concentrations in canine atopic dermatitis

BACKGROUND

Altered homeostasis of vitamin E has been demonstrated in human atopic dermatitis. Data on plasma and skin vitamin E concentrations in canine atopic dermatitis (CAD) are not available.

OBJECTIVE

To determine vitamin E concentrations in plasma and skin of atopic dogs.

ANIMALS AND METHODS

Vitamin E concentrations in plasma and full-thickness skin biopsies of 15 atopic dogs were related to CAD extent and severity index (CADESI-03) scores and compared to the equivalent concentrations in 17 healthy dogs. Statistically significant differences of measured parameters between the two groups were determined by the nonparametric Mann Whitney U test and correlations between CADESI-03 scores and vitamin E concentrations were evaluated by the Spearman rank test. A value of P < 0.05 was considered significant.

RESULTS

Plasma concentrations of vitamin E were significantly lower in atopic dogs than in healthy dogs, with median values of 29.8 and 52.9 μmol/L, respectively. Skin vitamin E values did not differ significantly between patients and healthy controls. The median concentration of skin vitamin E in atopic dogs was higher than that in healthy dogs. No significant correlations were found between CADESI-03 score and plasma vitamin E or skin vitamin E concentrations.

CONCLUSIONS

Significantly lower plasma vitamin E concentrations in atopic dogs than in healthy controls indicate altered homeostasis of vitamin E in CAD.

CLINICAL IMPORTANCE

Further investigation into vitamin E supplementation in CAD is warranted.

Evaluation of the effect of a 0.0584% hydrocortisone aceponate spray on clinical signs and skin barrier function in dogs with atopic dermatitis

The purpose of this study was to evaluate the effects of a topical spray containing 0.0584% hydrocortisone aceponate (HCA) on canine atopic dermatitis (CAD) and to evaluate the skin barrier function during the treatment of CAD. Twenty-one dogs that fulfilled the diagnostic criteria for CAD were included in this study. The HCA spray was applied once a day to the lesions of all dogs for 7 or 14 days. Clinical assessment was performed before (day 0) and after treatment (day 14), and clinical responses were correlated with changes in skin barrier function. CAD severity significantly decreased after 14 days of HCA treatment based on the lesion scores (p < 0.0001), which were determined using the CAD extent and severity index (CADESI-03) and pruritus scores (p < 0.0001) calculated using a pruritus visual analog scale. Transepidermal water loss, a biomarker of skin barrier function, was significantly reduced compared to baseline (day 0) measurements (p = 0.0011). HCA spray was shown to be effective for significantly improving the condition of dogs suffering from CAD. This treatment also significantly improved cutaneous hydration and skin barrier function in the animals.

The Influence of Topical Unsaturated Fatty Acids and Essential Oils on Normal and Atopic Dogs

Seven dogs with atopic dermatitis and six normal dogs were treated with a spot-on product containing essential oils and unsaturated fatty acids q 7 days for 8 wk. Seven additional atopic dogs received a daily spray containing similar ingredients to the spot-on. In all dogs, transepidermal water loss (TEWL) was measured before and after treatment using a closed chamber device. In atopic dogs, a validated lesion score (canine atopic dermatitis extent and severity index, CADESI) was determined and pruritus was assessed with a visual analog scale before and after treatment. The mean CADESI scores in atopic dogs decreased with the spot-on (P=0.0043) and with the spray (P=0.0366). Similarly, the pruritus scores decreased with the spot-on (P=0.266) and with the spray (P=0.0177). There was a significant difference between the TEWL values of healthy and atopic dogs on the abdomen (P=0.0181) and back (P=0.0123). TEWL decreased significantly on the back after treatment with the spray (P=0.016), but not on the abdomen (P=0.078). Adverse effects were not observed. The results of this pilot study indicate that topical fatty acids and essential oils are a useful treatment option for canine atopic dermatitis.

Oxidative stress markers in canine atopic dermatitis

There are no data in the veterinary literature relating to oxidative stress in canine atopic dermatitis (CAD). The study aimed to determine levels of oxidative stress markers, plasma malondialdehyde (MDA), total antioxidant capacity (TAC), whole blood glutathione peroxidase (GPX) and erythrocyte superoxide dismutase (SOD), in 15 CAD patients and 17 healthy dogs. A correlation between CADESI (Canine Atopic Dermatitis Extent and Severity Index) score and MDA was also determined. Significantly higher plasma MDA levels were found in patients than in healthy dogs. The significant, highly positive correlation determined between CADESI score and MDA in the patient group indicates an association between the severity of CAD and the extent of oxidative damage to membrane lipids. There were no significant differences in TAC, GPX and SOD between patients and healthy dogs. Our findings suggest that oxidative stress with increased lipid peroxidation could be involved in the pathogenesis of atopic dermatitis in dogs.

Evaluation of the bacterial microflora of the conjunctival sac of healthy dogs and dogs with atopic dermatitis

The aim of this case-control study was to evaluate and compare the bacterial microflora from the conjunctival sac of dogs with atopic dermatitis and healthy dogs. Twenty-one atopic dogs without clinical and/or cytopathological signs of bacterial blepharoconjunctivitis and 21 breed-matched healthy dogs were enrolled. Under topical anaesthesia, the inferior conjunctival sac of one eye was scraped twice. Material was collected with a Kimura spatula, spread over a slide and stained with a Diff Quick(®) -type stain (Medion Diagnostics GmbH, Düdingen, Switzerland) for cytological examination. An area of 0.5 cm(2) was examined at ×1000 magnification, and the types and numbers of cells and bacteria were recorded. A bacterial swab was collected and inoculated into culture media for the growth of aerobic bacteria. Before sampling, each atopic dog was evaluated for severity of cutaneous lesions, pruritus and conjunctival inflammation. Significant differences were observed between atopic and healthy dogs for the presence of bacteria on cytology (P = 0.015), keratinized (P = 0.001) and nonkeratinized epithelial cells (P = 0.013), eosinophils (P = 0.019) and lymphocytes (P = 0.008). Bacteria were recovered from 12 atopic dogs and three healthy dogs (P = 0.004). Staphylococcus pseudintermedius was the most commonly isolated species in atopic dogs (seven of 12). In atopic dogs, no significant relation was found between conjunctival bacterial colonization (on cytology and culture) and the severity of any of the clinical parameters. This study suggests differences in conjunctival bacterial colonization and cytological features between atopic and healthy dogs.

Elevated serum levels of S100 calcium binding protein A8 (S100A8) reflect disease severity in canine atopic dermatitis

A monoclonal antibody to canine S100 calcium binding protein A8 (S100A8) was developed to determine the association between S100A8 and the disease severity of canine atopic dermatitis. Serum S100A8 concentrations were studied in dogs with canine atopic dermatitis (n=213) and healthy dogs (n=213). Statistical correlations between these indices and atopic dermatitis activity were established, and dermatitis severity was assessed according to the CADESI score. Serum S100A8 concentrations were measured with an enzyme-linked immunosorbent assay (ELISA). S100A8 serum levels were significantly higher in canine atopic dermatitis patients than in healthy dogs. A strong positive correlation was identified between S100A8 levels and canine atopic dermatitis patients. Our findings suggested that S100A8 is actively involved in the pathogenesis and clinical picture of canine atopic dermatitis.

Masitinib for the treatment of canine atopic dermatitis: a pilot study

There is an on-going need to identify medications suitable for the long-term treatment of canine atopic dermatitis (CAD). Masitinib mesilate is a potent and selective tyrosine kinase inhibitor of the c-KIT receptor. A strong relationship exists between the SCF/c-KIT pathway and pathogenesis of CAD, suggesting that masitinib may potentially fulfil the above role. This study reports on an uncontrolled pilot study of masitinib in CAD. Masitinib was administered orally to 11 dogs at a mean dose of 11.0 +/- 1.83 mg/kg/day (free base) for 28 days. Treatment response was assessed by evolution of clinical appearance according to a modified version of the Canine Atopic Dermatitis Extent and Severity Index (mCADESI), pruritus scale and surface area of lesions. Masitinib improved CAD with a mean reduction in mCADESI of 50.7 +/- 29.8% (95% C.I. = 29.4-72.0; p = 0.0004) at day 28 relative to baseline, with 8/10, 8/10 and 4/10 dogs showing improvement of >or=33%, >or=40% and >or=50%, respectively. Improvement was further evidenced by a decrease in pruritus score and the surface area of lesions. No serious or severe adverse events occurred during this trial, although 6/11 dogs presented with mild to moderate treatment related adverse events. There is sufficient compelling evidence to warrant further investigation.