Evidence-based veterinary dermatology: a systematic review of the pharmacotherapy of canine atopic dermatitis

Exploring montelukast in dogs: A preliminary pharmacokinetic study following oral administration under fasted and fed conditions

This study investigates the pharmacokinetics (PK) of montelukast (MTK), a cysteinyl leukotriene receptor antagonist increasingly being considered in veterinary medicine. In dogs, MTK has found indications mainly for treating atopic dermatitis as an off-label use. Six male Labrador dogs underwent a single oral administration of MTK (40 mg/dog) in both fasted and fed conditions according to an open, single-dose, two-treatment, two-phase, cross-over design, with a washout period of one week. Blood was withdrawn to heparinized tubes at 0, 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, and 24 hr. MTK plasma concentrations were quantified using a validated HPLC method, and the data were analysed using PKanalix™ software with a non-compartmental approach. Concentrations remained quantifiable at 24 hr after administration, under both conditions. No significant differences were observed in the PK parameters between the fasted and fed states. MTK was relatively eliminated slowly, with t1/2 values of 8.10 and 7.68 hr after fasted and fed states, respectively. The attainment of maximum concentration (Cmax) occurred at a Tmax of 4 hr, with mean values of 1.98 μg/mL and 2.80 μg/mL under fasted and fed conditions, respectively. Given the unknown therapeutic range of MTK in dogs and the absence of controlled studies proving its efficacy in this species, further dosing adjustments and refinements should be considered based on both the current PK data and the need to establish an effective therapeutic range, if present. Future research should focus on efficacy studies, multiple-dose investigations, and pharmacodynamic assessments to evaluate the suitability of MTK use in dogs.

Prednisolone prescribing practices for dogs in Australia

Although prednisolone is a routinely prescribed medication in dogs, there is a lack of information regarding prednisolone prescribing practices by veterinarians. This study aims to describe characteristics of dogs receiving prednisolone, disease processes treated, doses prescribed as well as to identify factors influencing the dose rate in Australia. The VetCompass Australia database was queried to identify dogs prescribed prednisolone between 1 July 2016 to 31 July 2018 (inclusive). A random sample of 2,000 dogs from this population were selected. Dog demographic data, prednisolone dose and indication for prescription were collated. Indicated dose for the condition treated was compared to prescribed dose. Multivariable linear regression was used to identify patient-level characteristics associated with prescribed prednisolone dose. A large and small breed dog cohort, treated for the same disease process, were compared for differences in dosing. Median age of dogs was 73 (range 2 to 247) months and median body weight was 17 (range 1.56 to 90) kg. Median prescribed prednisolone dose was 0.8 mg/kg/day, with most dogs receiving an anti-inflammatory dose (0.3-1 mg/kg/day, 58%). Prednisolone prescriptions were predominantly for diseases of the integument (n = 1645, 82%) followed by unknown indication and respiratory disease. A total of 152 dogs (8%) were prescribed immunosuppressive doses of prednisolone for conditions where an anti-inflammatory dose would be recommended. Increases in bodyweight were associated with lower doses on mg/kg scale but higher doses on a mg/m2 scale (p < 0.001). Overall, prednisolone was primarily used as an anti-inflammatory in this population, with some inappropriate use of immunosuppressive doses. Increasing bodyweight was associated with a small reduction in dose in mg/kg, suggesting that clinicians are adjusting prednisolone dose rates based on dog bodyweight.

Recombinant human interferon-α14 for the treatment of canine allergic pruritic disease in eight dogs

BACKGROUND

Allergic pruritic diseases are increasingly common in dogs. This group of conditions hampers life quality as pruritus progressively interferes with normal behaviours. Therefore, new treatment modalities for canine allergic pruritic diseases are necessary. While novel drugs have recently reached the market, there is still the need for other therapeutic approaches. Some dogs are refractory even to the newer compounds, and cost is also an important issue for these. Older therapeutic modalities are only moderately successful or have considerable secondary effects, as is the case with glucocorticoids.

OBJECTIVES

Report on the use of recombinant human interferon-α14 (rhIFN-α14) for the treatment of canine allergic pruritus. Following the experience with a similar compound in the Japanese market, it was expected that rhIFN-α14 could alter the Th1/Th2 disbalance that drives these diseases.

METHODS

Here, we present an uncontrolled trial in which eight dogs with clinical diagnosis of allergic pruritus were treated with rhIFN-α14, either orally or via subcutaneous injections. Skin condition, microbiota and anti-interferon antibody levels were assessed.

RESULTS

The parenteral use of interferon induced hypersensitivity in two of the three dogs in which it was used. The oral administration was consistently safe and could reduce signs of the allergic condition in three of the five treated animals. Treatment also altered the skin microbiota, as verified by next-generation sequencing.

CONCLUSION

The present results indicate that rhIFN-α14 is a viable candidate for the treatment of canine allergic pruritus. Future controlled studies are needed, and the oral route is indicated for further trials.

What are the highest yielding search strategy terms for systematic reviews in atopic dermatitis? A systematic review

The impact of search strategies on systematic reviews (SR) of atopic dermatitis (AD) is unknown. The purpose of this review was to evaluate search strategies used in SR of AD and their impact on the frequency of manuscripts identified. MEDLINE and EMBASE were searched for SR related to AD. Simulations were performed by running combinations of search terms in MEDLINE and EMBASE. Overall, 250 SR met inclusion criteria, of which 225 specified search strategies. SR using 5-6 terms (20.0% to 12.1%) or ≥ 7 (40.0% to 18.8%) terms decreased, whereas SR using 3-4 terms numerically increased (18.8% to 30.2%) and 1-2 terms remained similar (37.5% to 38.9%) from 1999-2009 to 2015-2019. The most commonly searched terms were "atopic dermatitis" (n = 166), followed by "eczema" (n = 156), "dermatitis atopic'" (n = 81), "atopic eczema" (n = 74), "neurodermatitis" (n = 59), "Besniers prurigo" (n = 29), "infantile eczema" (n = 27), and "childhood eczema" (n = 19). Simulations revealed that "eczema" and "atopic dermatitis" yielded the most hits. The number of search terms that maximized hits in MEDLINE and EMBASE was 5 and 4, respectively. Search strategies for AD were heterogeneous, with high proportions of search strategies providing few search hits. Future studies should use standardized and optimized search terms.

Clinical effects of 2 commercially available diets on canine atopic dermatitis

OBJECTIVE

Canine atopic dermatitis (CAD) is a common skin disease in dogs. Prior studies were able to determine beneficial effects of essential fatty acids (EFA) on the clinical signs of CAD. The aim of this study was set to evaluate the effects of a newly designed, EFA-enriched diet on the clinical signs of CAD compared to another EFA-enriched diet.

MATERIALS AND METHODS

In this prospective, randomized, double-blinded study, 31 privately owned dogs with atopic dermatitis received either the control diet (diet A, Hill's Prescription Diet™ d/d™ Salmon & Rice, n = 17) or the test diet (diet B, Veterinary HPM™ Dermatology Support D1, Virbac, n = 14) for 12 weeks. At the beginning of the study as well as after 4, 8 and 12 weeks, skin lesions and pruritus were evaluated via validated scores and the administered medication was documented. At the same time, the dogs' coat quality was evaluated via a distinct scoring system. In both groups, a total of 7 dogs each completed the entire study.

RESULTS

After 12 weeks, there was a mild improvement in lesion scores, pruritus and coat quality with both diets.

CLINICAL RELEVANCE

In this study, both diets improved the patients' skin lesions pruritus and coat quality.

Corticosteroid treatment for acute/acute-on-chronic experimental and naturally occurring pancreatitis in several species: a scoping review to inform possible use in dogs

Acute pancreatitis in dogs is a prevalent disease characterised by mild to severe inflammation. Treatment with anti-inflammatory corticosteroids has been widely debated but is not generally recommended in veterinary medicine. The objective of the present study was to present current evidence on the effect of corticosteroid treatment for acute/acute-on-chronic pancreatitis across species. These findings were then used to evaluate if and how corticosteroid treatment could influence disease outcome in canine acute/acute-on-chronic pancreatitis. A scoping review was performed by searching the Agricola, CAB Abstracts, MEDLINE and Embase databases to identify relevant articles published before June 24, 2021. The inclusion criteria were English language, original research published in a peer-reviewed journal, and investigation of corticosteroid treatment effects on acute/acute-on-chronic pancreatitis by the outcome parameters clinical score, circulating CRP level, hospitalisation duration, mortality and pancreas histopathology. Research on any species was considered. Studies were rated based on the level of evidence, and methodological quality was evaluated based on similarity between groups at baseline, risk of bias and study group size. The reporting method was based on the PRISMA extension for scoping reviews. One thousand nine hundred fifty-four studies were identified, and 31 met the inclusion criteria. Five were canine studies, with 4 investigating experimentally induced pancreatitis; 5 were human clinical studies; and 21 were rodent studies of experimentally induced pancreatitis. The level of evidence ranged between randomised controlled trials and case series, the estimated risk of bias ranged from low to high, and the sample sizes ranged from very small to moderate. Evidence indicates that adding corticosteroid to symptomatic treatment of acute/acute-on-chronic canine pancreatitis could have a positive influence on disease outcome. However, the analysed evidence was based on several species, including both naturally occurring and experimentally induced pancreatitis; thus, the authors suggest that large randomised controlled studies should be performed in dogs with spontaneously occurring acute/acute-on-chronic pancreatitis to further elucidate a potential benefit of corticosteroid treatment.

A masked, randomised clinical trial evaluating the efficacy and safety of lokivetmab compared to saline control in client-owned dogs with allergic dermatitis

Background

Interleukin (IL)‐31 is an important mediator in canine atopic dermatitis (cAD) and also may be dysregulated in other allergic diseases.

Hypothesis/Objectives

To demonstrate the efficacy and safety of lokivetmab (canine anti‐IL‐31 monoclonal antibody) for treatment of pruritus associated with allergic dermatitis in dogs.

Animals

Dogs that were at least moderately pruritic with a presumptive diagnosis of allergic dermatitis were enrolled in Portugal, Hungary, France and Germany by 12 primary care practitioners and two veterinary dermatology referral specialists.

Methods and materials

Dogs were randomised to receive either placebo (saline) or lokivetmab (1.0–3.3 mg/kg) by subcutaneous injection on Day (D)0. Owners evaluated pruritus using a validated Visual Analog Scale (pVAS) daily until D7 and then weekly until D28. The severity of dermatitis was assessed by the investigators using a modified VAS on D0, D7, D14 and D28.

Results

Beginning at D1, owner‐assessed pVAS least square means were significantly reduced in the treatment group versus the placebo group (57.7% versus 21.8% reduction on D28). For all time points, investigator‐assessed VAS means were significantly reduced in the lokivetmab group versus the placebo group (57.1% versus 20.5% reduction on D28). Overall, the occurrence of adverse health events during the evaluation period was comparable between the two groups.

Conclusions and clinical importance

Lokivetmab is a safe and efficacious treatment for dogs with allergic dermatitis.

A systematic review of moxidectin as a treatment for parasitic infections in mammalian species

Moxidectin (MOX) is a macrocyclic lactone approved worldwide for the treatment of both endo- and ecto-parasites in many mammalian species. The aim of this study was to assess the efficacy of MOX as a treatment against parasites in a range of mammalian species. An electronic literature search was performed for publications to the 1^st September 2020. A total of 205 papers were retrieved and screened against all required criteria; hence, 35 were papers were reviewed in this study. The level of evidence and methodological quality was analysed, where a total of 13 publications were categorised as a 'randomised control trial', seven were categorised as a 'non-randomised control trial' and 15 as an 'experimental control trial'. The overall methodological quality of the publications was considered low, low to moderate, moderate, moderate to high and high in ten, four, twelve, five and a further four, respectively. We assessed the treatment and possible toxicity of MOX in 13 mammalian species, six investigations reported adverse effects to MOX in a small percentage of individuals. The authors reported observed reactions that were typically mild symptoms that did not require additional therapies, and/or resolved themselves. Further studies are needed to assess the efficacy of MOX treatment in a larger number of species, particularly in wildlife.

Impact of Nutritional Supplementation on Canine Dermatological Disorders

Nutritional supplements, also known as complementary feeds, are products administered with the aim of furnishing health benefits, regardless of nutritional needs. They have been used since ancient times in veterinary dermatology, and a number of studies have focused on investigating the health benefits of some ingredients found in commercially available complementary feed for dogs. The aim of this paper is to review the literature available on the use of nutritional supplementation for the management of canine skin diseases, critically appraising the clinical efficacy of such interventions and summarizing the current state of knowledge. This review highlights how these feeds can be considered useful in the management of dermatological disorders and outlines their beneficial effects in the prevention of dietary deficiencies and treatment of diseases, alone, or in addition to conventional pharmacological therapy. In recent years, nutritional supplements have found increasing potential application in veterinary medicine, and the scientific proofs of their beneficial effects are described in this review.

Development and validation of a graphic 2D investigator's global assessment instrument for grading the overall severity of atopic dermatitis in dogs

BACKGROUND

Clinical trials enrolling dogs with atopic dermatitis (AD) use validated instruments that aggregate the extent and severity of selected skin lesions; none of these provides a global assessment of the severity of all lesions.

OBJECTIVES

To validate an Investigator Global Assessment (IGA) instrument to globally evaluate the severity of skin lesions in dogs with AD.

ANIMALS

Forty dogs with AD.

METHODS AND MATERIALS

A 2D graphic IGA (2D-IGA) instrument was created to subjectively score, with a single dot, the overall extent and severity of all canine AD lesions. This tool was tested for its validity (content, construct and criterion), reliability (inter- and intraobserver) and sensitivity to change.

RESULTS

The content of the 2D-IGA was first validated by a supportive vote by the International Committee of Allergic Diseases of Animals (ICADA) membership. Its construct was verified by positive correlations between the 2D-IGA scores and those of the Canine Atopic Dermatitis Extent and Severity Index, 4^th iteration (CADESI-04) and the Canine Atopic Dermatitis Lesion Index (CADLI) (Spearman's rank-order correlation, P < 0.0001). The positive correlation (P < 0.0001) between an Owner Global Assessment of Disease Severity (OGADS) and the 2D-IGA indirectly satisfied its criterion. Scores graded by the same investigator hours apart and those between investigators were positively correlated (P < 0.0001), thereby validating this scale's intra- and interobserver reliabilities. Finally, the changes in 2D-IGA values during treatment were correlated positively with scores of an Owner Global Assessment of Treatment Efficacy (OGATE; P < 0.0001), thus showing its sensitivity to change.

CONCLUSIONS AND CLINICAL IMPORTANCE

This novel 2D-IGA is a simple static graphic instrument that could be useful for clinical trials testing the efficacy of interventions for canine AD.

Clinical effect of probiotics in prevention or treatment of gastrointestinal disease in dogs: A systematic review

BACKGROUND

Gastrointestinal diseases are prevalent in dogs, and probiotics could provide safe alternatives to conventional treatments.

OBJECTIVE

To evaluate the clinical effects of probiotics when used in the prevention or treatment of gastrointestinal disease in dogs compared with no treatment, only symptomatic treatment, or conventional treatment.

METHODS

A systematic review was preformed searching AGRICOLA, AGRIS, CAB Abstracts, Embase, Ovid MEDLINE, and Web of Science to identify articles published before April 1, 2017. Selection criteria were original research report, those published in peer reviewed journal, and study investigating in vivo use of probiotic for prevention or treatment of gastrointestinal disease in dogs. Studies were rated based on the level of evidence, and methodological quality was evaluated by the following variables: similarities between groups at baseline, risk of bias, and study group size.

RESULTS

One hundred sixty-five studies were identified, of which 17 met the inclusion criteria-12 concerned acute gastrointestinal disease and 5 concerned chronic gastrointestinal disease. The level of evidence ranged between randomized controlled studies and crossover uncontrolled trials; estimated risk of bias was generally moderate to high; and sample sizes were small. Feces consistency was the most frequently evaluated clinical variable.

CONCLUSIONS AND CLINICAL IMPORTANCE

The current data point toward a very limited and possibly clinically unimportant effect for prevention or treatment of acute gastrointestinal disease. For chronic gastrointestinal disease, dietary intervention remains the major key in treatment, whereas probiotic supplement seems not to add significant improvement. However, studies were often underpowered, underscoring the need for future larger, preferably multicenter studies.

Atopic dermatitis in cats and dogs: a difficult disease for animals and owners

The purpose of this review article is to give an overview of atopic dermatitis in companion animals and of recent developments including knowledge on immunological background, novel treatment options and difficulties in disease management. The prevalence of hypersensitivities seems to be increasing. The pathogenetic mechanisms are not fully understood, yet multiple gene abnormalities and altered immunological processes are involved. In dogs and cats, the diagnosis of atopic dermatitis is based on history, clinical examination and exclusion of other differential diagnoses. Intradermal testing or testing for serum allergen-specific Immunoglobulin E is only used to identify allergens for inclusion in the extract for allergen immunotherapy. Symptomatic therapy includes glucocorticoids, ciclosporin, essential fatty acids and antihistamines. A selective janus kinase 1 inhibitor and a caninized monoclonal interleukin-31 antibody are the newest options for symptomatic treatment, although longterm effects still need to be assessed. The chronic and often severe nature of the disease, the costly diagnostic workup, frequent clinical flares and lifelong treatment are challenging for owners, pets and veterinarians. Patience and excellent communication skills are needed to achieve a good owner compliance and satisfactory clinical outcome for the animal.

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.

Vitamin D shows in vivo efficacy in a placebo-controlled, double-blinded, randomised clinical trial on canine atopic dermatitis

Atopic dermatitis (AD) in dogs is among the most common skin diseases in small animal practice. It is an inflammatory disease based on a genetic predisposition to develop hypersensitivity against environmental and food allergens and typical clinical signs up exposure. Treatment sometimes can be difficult and associated with adverse effects. Previous studies evaluating cholecalciferol as treatment for human AD have shown promising results. With canine AD being a good animal model for its human counterpart, it was hypothesised that cholecalciferol might have beneficial clinical effects in dogs, too. In this randomised, placebo-controlled, double-blinded eight-week cross-over study, 23 client-owned dogs received either systemic cholecalciferol (n=16), a vitamin D receptor analogue (n=8) or placebo (n=13). Blood samples for ionised calcium were obtained regularly during the study, and Canine Atopic Dermatitis Extent and Severity Index and pruritus scores, blood levels of vitamin D metabolites, measurements of skin pH and transepidermal water loss were determined before and after. Pruritus and lesion scores decreased significantly in the cholecalciferol group versus placebo. No differences in water loss or skin pH were observed. An increase in serum 25-hydroxycholecalciferol strongly correlated with a reduction in pruritus. Systemic cholecalciferol may be a viable treatment option for canine AD.

A study on periostin involvement in the pathophysiology of canine atopic skin

Atopic dermatitis (AD) is a chronic, pruritic, and allergic skin disease in humans and animals, particularly dogs. Canine AD (cAD) has received attention as a spontaneous atopic animal model because domesticated dogs inhabit a human environment, and cAD shares several clinicopathological features with human AD (hAD). In hAD, periostin (PO) is suggested to play a critical role in the enhancement and chronicity of allergic skin inflammation; however, PO involvement in the pathogenesis of cAD is unknown. Here we aimed to clarify PO involvement in the pathophysiology of cAD and focused on the inducing factor and function of PO in canine atopic skin. Using double-labeled in situ hybridization (ISH), interleukin (IL)-13 mRNA-positive cells were detected near the keratinocytes and dermal fibroblasts expressing PO mRNA in atopic skin. Using an in vitro assay, IL-13 induced PO gene expression in both canine dermal fibroblasts and keratinocytes. PO enhanced in vitro growth of canine keratinocytes. Moreover, among PO-induced genes in cultured canine keratinocytes detected using a microarray, we identified IL-25 as a possible mediator in canine atopic skin. In addition, real time polymerase chain reaction (PCR) analysis revealed upregulation of IL-25 gene expression in PO-stimulated keratinocytes. These data suggest that IL-13 possibly derived from T helper 2 (Th2) cells stimulates PO production in both keratinocytes and fibroblasts, and then PO may play a critical role in the pathophysiology of cAD, particularly in the enhancement and chronicity of skin lesions via IL-25.

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.

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.

An update on the treatment of canine atopic dermatitis

Canine atopic dermatitis is a common skin disease seen in veterinary clinical practice. Several factors appear to contribute to the cutaneous inflammation and pruritus. The therapeutic strategy should focus on control of those factors that can be identified and for which interventional measures are feasible; these include ectoparasites, bacterial/fungal infection and dietary hypersensitivity. Ectoparasites, particularly fleas, are not the cause of atopic dermatitis, but they are a confounding factor, which can exacerbate pruritus, and preventative measures are therefore indicated. Bacterial and yeast infections are frequently associated with atopic dermatitis and initial systemic and/or topical therapy should be considered, followed by regular topical treatment for preventing relapse. Concurrent dietary hypersensitivity should be investigated by undertaking an elimination/provocation trial, followed by feeding of a hypoallergenic diet where appropriate. Depending on the severity of the clinical signs of atopic dermatitis and the willingness and expectations of owners, symptomatic treatment and/or specific interventional therapy for environmental allergy (allergen avoidance, allergen-specific immunotherapy) may be implemented. Symptomatic treatment includes use of glucocorticoids (systemically or topically), ciclosporin and oclacitinib. Other treatment modalities of lower or less proven efficacy include antihistamines, dextromethorphan, fatty acids, feline interferon-omega, misoprostol, pentoxifylline, specific serotonin re-uptake inhibitors and tricyclic antidepressant drugs. The therapeutic approach should be reviewed at regular intervals and tailored to the individual's needs. A successful long-term outcome can usually be achieved by combining the various treatment approaches in a way that maximises their benefits and minimises their drawbacks.

Treatment of canine atopic dermatitis: 2015 updated guidelines from the International Committee on Allergic Diseases of Animals (ICADA)

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.

Introduction to systematic reviews in animal agriculture and veterinary medicine

This article is the first in a series of six articles related to systematic reviews in animal agriculture and veterinary medicine. In this article, we overview the methodology of systematic reviews and provide a discussion of their use. Systematic reviews differ qualitatively from traditional reviews by explicitly defining a specific review question, employing methods to reduce bias in the selection and inclusion of studies that address the review question (including a systematic and specified search strategy, and selection of studies based on explicit eligibility criteria), an assessment of the risk of bias for included studies and objectively summarizing the results qualitatively or quantitatively (i.e. via meta-analysis). Systematic reviews have been widely used to address human healthcare questions and are increasingly being used in veterinary medicine. Systematic reviews can provide veterinarians and other decision-makers with a scientifically defensible summary of the current state of knowledge on a topic without the need for the end-user to read the vast amount of primary research related to that topic.

Conducting systematic reviews of intervention questions II: Relevance screening, data extraction, assessing risk of bias, presenting the results and interpreting the findings

This is the fifth in a series of six articles describing systematic reviews in animal agriculture and veterinary medicine. The previous articles in this series overviewed the development of a review protocol and the initial steps in conducting a systematic review: identification of a structured question to be answered and conducting a comprehensive literature search to find potentially relevant original research to address the review question. This article describes relevance screening of literature identified in the search to determine which of the original research articles are relevant to the review question, data extraction from primary research studies, the use of standardized procedures to assess the risk of bias in the relevant research studies, presenting the results of the body of research identified and interpreting these results.

An introduction to systematic reviews in animal health, animal welfare, and food safety

In this paper, we provide an introduction to systematic reviews and discuss the process for conducting systematic reviews in animal health, animal welfare, and food safety. The research synthesis need that can be addressed by a systematic review is discussed. The use of systematic reviews to address questions about intervention effects, etiology, diagnostic tests evaluation and disease burden are discussed. The steps included in a systematic review are described.

Expression of Periostin in Normal, Atopic, and Nonatopic Chronically Inflamed Canine Skin

In humans, periostin plays a critical role in the enhancement and chronicity of allergic skin inflammation; however, whether it is involved in the pathogenesis of canine dermatitis remains unknown. The aim of this study was to examine the expression patterns of periostin in healthy, atopic, and nonatopic chronically inflamed canine skin. Biopsy specimens from 47 dogs with skin disease and normal skin tissue from 5 adult beagles were examined by light microscopy, immunohistochemistry, and in situ hybridization. In normal skin, periostin was localized just beneath the epidermis and around the hair follicles. In chronically inflamed skin, periostin expression was most intense in the dermis with inflammatory cell infiltrates. In contrast, low levels of periostin were detected in acutely inflamed and noninflamed skin. Conversely, all canine atopic dermatitis tissues characteristically showed the most intense expression of periostin in the superficial dermis, particularly at the epidermal–dermal junction. In situ hybridization showed that periostin mRNA was broadly expressed in the basal epidermal keratinocytes, outer root sheath cells, and dermal fibroblasts in normal dog skin. High expression of periostin mRNA was observed in fibroblasts in dog skin with chronically inflamed dermatitis. Moreover, in some chronically inflamed skin specimens, periostin mRNA expression was increased in basal keratinocytes. The severity score of chronic pathologic changes and CD3+ cell number in the dermis were correlated with distribution pattern of periostin in the atopic skin. These data suggest that periostin could play a role in the pathophysiology of chronic dermatitis, including atopic dermatitis, in dogs.

Atopic itch in dogs: pharmacology and modeling

Itch is the most common clinical problem seen in dogs with skin diseases. Although an etiological classification of canine pruritus does not yet exist, most causes would likely fall into the IFSI class I (dermatological) itch. One of the most common causes of canine itch is that associated with atopic dermatitis, and there is randomized controlled trial grade evidence of the efficacy of several antipruritic interventions. At this time, the mainstay of treatment of canine atopic itch relies principally on the use of topical and/or oral glucocorticoids and oral cyclosporine. Type 1 receptor antihistamines are notorious in their inconsistency in reducing pruritus in atopic dogs. A new Janus kinase (JAK)-1 inhibitor has recently been approved for treatment of allergic itch in dogs, and its onset of efficacy is remarkably fast. Modeling itch in dogs can be achieved by allergen sensitization (fleas, house dust mites), and challenges that elicit pruritic manifestation can be used for mechanistic studies as well as for testing of novel anti-itch modalities.

Effect of antibiotic treatment in canine and feline urinary tract infections: a systematic review

Urinary tract infection (UTI) is a major reason for antibiotic prescription in small animal practice. Optimal antibiotic treatment strategies have not been established for veterinary species, especially when considering duration of treatment, which is often considerably longer than for human patients with UTI. The aims of this study were (1) to identify and assess evidence related to the efficacy of antibiotic treatment in canine and feline UTIs; and (2) to compare the efficacy of short (<5 days) and standard (≥7 days) duration of antibiotic treatment for canine uncomplicated UTI. An electronic literature search was conducted for publications to 1 May 2014. Fourteen peer-reviewed prospective and controlled studies were retrieved, 10 of which evaluated antibiotic treatment in dogs and four in cats. Of the 14 studies, seven were clinical trials and five of those were randomised controlled trials. Most (12/14) studies were not considered to contribute sufficient evidence to evaluate treatment strategies. There were no clinical studies examining the effect of duration of the same drug. Of the short duration regimens evaluated, the efficacy of 3 day antibiotic therapy with trimethoprim-sulphonamide (females only) or high-dose enrofloxacin in dogs with uncomplicated UTIs was supported by fair evidence, as these treatment strategies were non-inferior to medium duration (10-14 days) therapy with β-lactam antimicrobials. In conclusion, there is little published evidence relating to antibiotic treatment of UTIs in dogs and cats. Well-designed clinical trials focusing on the duration of treatment are warranted to create evidence-based treatment protocols.

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.

Invited review: Antibiotic treatment of metritis in dairy cows: a systematic approach

Acute puerperal metritis (APM) is an acute systemic illness with fever ≥ 39.5 °C and signs of toxemia due to an infection of the uterus occurring within 21 d after parturition. Because of the infectious nature of APM, antibiotics are considered beneficial for its treatment. Each use of an antimicrobial drug, however, is associated with selective pressure for the emergence of resistant bacteria. Hence, there is a significant need to encourage prudent use of antibiotics and alternative therapies to antibiotics. Therefore, the objective of this study was to systematically review the current literature on treatment of APM. A comprehensive and systematic literature search was conducted utilizing the PubMed and CAB Abstracts databases to identify literature focusing on the antibiotic therapy of puerperal metritis in the cow. After application of specific exclusion criteria, 21 publications comprising 23 trials remained for final evaluation. Data extraction revealed that the majority of the studies (n = 19) were attributable to the highest evidence level. Of 21 studies controlled, 11 had an untreated group and 3 a positive control group. The majority of the studies (n = 17) applied ceftiofur for the treatment of APM. Concerning the efficacy of ceftiofur, 7 studies observed clinical improvement, whereas none found improved reproductive performance. Fewer than half of the studies (n = 10) performed a bacteriological examination and only 4 implemented an antibiotic susceptibility test. Also, 3 studies (13.0%) described a self-cure rate per se. Little attention was given to the issue of bacterial resistance (n = 3), the need for reducing the application of antibiotics (n = 2), or guidelines for prudent use of antibiotics (n = 1). Our findings demonstrate that implementation of bacteriological examinations, sensitivity testing, and determination of minimum inhibitory concentrations, as well as reporting and discussion of critical issues (e.g., self-cure rates, resistance, prudent drug use), were suboptimal. On the other hand, the quality of studies on the treatment of APM was good, as indicated by evidence level 1. Nevertheless, more high-quality research considering self-cure rates is necessary to address critical issues related to APM and crucial to the dairy industry, such as resistance, prudent use of antibiotics, animal welfare, and cost-benefit ratios.

Efficacy of oclacitinib (Apoquel®) compared with prednisolone for the control of pruritus and clinical signs associated with allergic dermatitis in client-owned dogs in Australia

BACKGROUND

Oral glucocorticoids are widely used to reduce pruritus and dermatitis associated with allergic dermatitis. Data suggest that oclacitinib, a Janus kinase inhibitor, is a safe and effective alternative.

HYPOTHESIS/OBJECTIVES

To evaluate the efficacy and safety of oclacitinib compared with prednisolone for the control of pruritus associated with allergic dermatitis in a single-masked, controlled clinical trial with a randomized complete block design.

ANIMALS

Client-owned dogs (n = 123) with a presumptive diagnosis of allergic dermatitis and moderate to severe pruritus as assessed by the pet owner were enrolled.

METHODS

Dogs were randomized to treatment with either oclacitinib (0.4-0.6 mg/kg orally twice daily for 14 days, then once daily) or prednisolone (0.5-1.0 mg/kg once daily for 6 days, then every other day) for 28 days. An enhanced visual analog scale (VAS) was used by owners to assess pruritus and by veterinarians to assess dermatitis, at all time points assessed.

RESULTS

Both treatments produced a rapid onset of efficacy within 4 h. The mean reductions in pruritus and dermatitis scores were not significantly different between the treatments except on day 14, when reductions were more pronounced for oclacitinib than prednisolone (P = 0.0193 for owner pruritus scores; P = 0.0252 for veterinarian dermatitis scores). Adverse events were reported with similar frequency in both groups.

CONCLUSION AND CLINICAL IMPORTANCE

In this study, both oclacitinib and prednisolone provided rapid, effective and safe control of pruritus associated with allergic dermatitis, with substantial improvement in pruritus, reported by owners, and dermatitis, reported by veterinarians.

Clinical efficacy of low-level laser therapy on localized canine atopic dermatitis severity score and localized pruritic visual analog score in pedal pruritus due to canine atopic dermatitis

BACKGROUND

Canine atopic dermatitis is a genetically predisposed inflammatory skin disease often requiring multimodal treatment. There is a need to find further low-risk adjunctive therapies.

HYPOTHESIS/OBJECTIVES

To evaluate the localized effect of low-level laser therapy (LLLT) on the paws of dogs with atopic dermatitis using a localized canine atopic dermatitis severity score (LCADSS) and owner localized pruritic visual analog score (LPVAS) in comparison to treatment with a placebo.

ANIMALS

Thirty client-owned dogs with symmetrical pedal pruritus due to canine atopic dermatitis.

METHODS

Dogs were randomly assigned into two groups. In each group, one paw was treated with LLLT and one paw treated with a placebo laser (comparing either both fore- or hindpaws). Treatments were administered at 4 J/cm(2) (area from carpus/tarsus to distal aspect of digit 3) three times per week for the first 2 weeks and two times per week for the second 2 weeks. Scores were assessed for each paw at weeks 0, 2, 4 and 5.

RESULTS

There were no significant differences in LCADSS or LPVAS between LLLT and placebo treatments between weeks 0 and 5 (P = 0.0856 and 0.5017, respectively). However, LCADSS and LPVAS significantly decreased from week 0 at weeks 2, 4 and 5 in both LLLT and placebo groups (P < 0.0001 for all).

CONCLUSIONS AND CLINICAL IMPORTANCE

Low-level laser therapy is not an effective localized treatment for pedal pruritus in canine atopic dermatitis.

Ciclosporin 10 years on: indications and efficacy

Ciclosporin is a lipophilic cyclic polypeptide with powerful immunosuppressive and immunomodulatory properties that has been used in veterinary medicine for two decades. It is a calcineurin inhibitor whose principal mode of action is to inhibit T cell activation. The drug is principally absorbed from the small intestine and is metabolised in the intestine and liver by the cytochrome P450 enzyme system. Ciclosporin is known to interact with a wide range of pharmacological agents. Numerous studies have demonstrated good efficacy for the management of canine atopic dermatitis and this has been a licensed indication since 2003. In addition to the treatment of atopic dermatitis, it has been used as an aid in the management of numerous other dermatological conditions in animals including perianal fistulation, sebaceous adenitis, pododermatitis, chronic otitis externa and pemphigus foliaceus. This article reviews the mode of action, pharmacokinetics, indications for use and efficacy of ciclosporin in veterinary dermatology.

Life-long diseases need life-long treatment: long-term safety of ciclosporin in canine atopic dermatitis

Ciclosporin (Atopica; Novartis Animal Health) has been licensed for canine atopic dermatitis (AD) since 2002. Adverse events (AEs) have been reported in 55 per cent of 759 dogs in 15 clinical trials, but are rare in pharmacovigilance data (71.81 AEs/million capsules sold). Gastrointestinal reactions were most common, but were mild and rarely required intervention. Other AEs were rare (≤1 per cent in clinical trials; <10/million capsules sold). Hirsutism, gingival hyperplasia and hyperplastic dermatitis were rarely significant and resolved on dose reduction. Ciclosporin decreases staphylococcal and Malassezia infections in AD, and at the recommended dose is not a risk factor for other infections, neoplasia, renal failure or hypertension. The impact on glucose and calcium metabolism is not clinically significant for normal dogs. Concomitant treatment with most drugs is safe. Effects on cytochrome P450 and MDR1 P-glycoprotein activity may elevate plasma ciclosporin concentrations, but short-term changes are not clinically significant. Monitoring of complete blood counts, urinalysis or ciclosporin levels is not justified except with higher than recommended doses and/or long-term concurrent immunosuppressive drugs. Ciclosporin is not a contraindication for killed (including rabies) vaccines, but the licensed recommendation is that live vaccination is avoided during treatment. In conclusion, ciclosporin has a positive risk-benefit profile for the long-term management of canine AD.

A scoping review of published research on the relinquishment of companion animals

Globally, large populations of companion animals are relinquished each year. The purpose of this scoping review was to identify all published research investigating companion-animal relinquishment to map out and evaluate research gaps, needs, and opportunities. A comprehensive search strategy was implemented in 4 online databases, identified citations were screened, and relevant articles were procured and characterized. From 6,848 unique citations identified, 192 were confirmed relevant, including 115 primary-research articles and 77 reviews and commentaries. The majority of these articles originated from the United States (131; 68.2%); 74 (38.5%) of them have been published since 2006. Among the primary-research articles, 84 (73.0%) investigated reasons for companion-animal relinquishment. The most commonly studied reasons were aggressive companion-animal behaviors (49; 58.3%); moving, rental, or housing issues (45; 53.6%); and caretaker personal issues (42; 50.0%). Only 17 primary-research articles investigated interventions to prevent companion-animal relinquishment. The quantity of research into reasons for relinquishment highlights an opportunity for future knowledge-synthesis activities in this area, including systematic review and meta-analysis. In comparison, the limited research into interventions identifies a priority for new research.

Efficacy of dimetinden and hydroxyzine/chlorpheniramine in atopic dogs: a randomised, controlled, double-blinded trial

Antihistaminic drugs are commonly used as symptomatic therapy of atopic dermatitis in dogs. Unfortunately, their clinical benefit is largely unsubstantiated. In a double-blinded, placebo-controlled, cross-over trial, the influence of dimetinden and of a combination of chlorpheniramine and hydroxyzine on pruritus and lesions was evaluated in 19 dogs. They were treated with either product or a placebo orally for 14 days, each time followed by a 14-day washout period. Before and after each period, the dogs were examined and the Canine Atopic Dermatitis Extent and Severity Index (CADESI) determined by a clinician, and the pruritus and general condition by the owner. Dimetinden improved the pruritus significantly (P=0.014) but not the CADESI (P=0.087), the combination of hydroxyzine and chlorpheniramine improved the CADESI (P=0.049) and pruritus (P=0.05) significantly. Ten of 17 dogs improved by more than 25 per cent in pruritus with the combination of hydroxyzine and chlorpheniramine, 12 of 18 with dimetindenmaleate and only 2 of 19 with placebo. Antihistamines can help to reduce pruritus in atopic dogs, but in most cases, the improvement is limited and additional treatment may be needed.

Efficacy and safety of oclacitinib for the control of pruritus and associated skin lesions in dogs with canine allergic dermatitis

BACKGROUND

Oclacitinib (Apoquel(®) ) inhibits the function of a variety of pro-inflammatory, pro-allergic and pruritogenic cytokines that are dependent on Janus kinase enzyme activity. Oclacitinib selectively inhibits Janus kinase 1.

HYPOTHESIS/OBJECTIVES

We aimed to evaluate the safety and efficacy of oclacitinib for the control of pruritus associated with allergic dermatitis in a randomized, double-blinded, placebo-controlled trial.

METHODS

Client-owned dogs (n = 436) with moderate to severe owner-assessed pruritus and a presumptive diagnosis of allergic dermatitis were enrolled. Dogs were randomized to either oclacitinib at 0.4-0.6 mg/kg orally twice daily or an excipient-matched placebo. An enhanced 10 cm visual analog scale (VAS) was used by the owners to assess the severity of pruritus from day 0 to 7 and by veterinarians to assess the severity of dermatitis on days 0 and 7. Dogs could remain on the study for 28 days.

RESULTS

Pretreatment owner and veterinary VAS scores were similar for the two treatment groups. Oclacitinib produced a rapid onset of efficacy within 24 h. Mean oclacitinib Owner Pruritus VAS scores were significantly better than placebo scores (P < 0.0001) on each assessment day. Pruritus scores decreased from 7.58 to 2.59 cm following oclacitinib treatment. The day 7 mean oclacitinib Veterinarian Dermatitis VAS scores were also significantly better (P < 0.0001) than placebo scores. Diarrhoea and vomiting were reported with similar frequency in both groups.

CONCLUSIONS AND CLINICAL IMPORTANCE

In this study, oclacitinib provided rapid, effective and safe control of pruritus associated with allergic dermatitis, with owners and veterinarians noting substantial improvements in pruritus and dermatitis VAS scores.

Canine atopic dermatitis - what have we learned?

Canine atopic dermatitis is a complex multifactorial disease. Here, Tim Nuttall, Maarja Uri and Richard Halliwell, representing three generations of veterinary dermatologists, describe the research underpinning our understanding of the condition and highlight its relevance to clinical practice.

Nonsteroidal, nonimmunosuppressive therapies for pruritus

Pruritus, or itch, is defined as "a sensation that, if sufficiently strong, will provoke scratching or the desire to scratch." Pruritus is a symptom associated with a wide variety of causes and treatment options. Topical therapy is becoming the new target for the treatment of pruritus. The treatment of pruritus in the dog must be approached in a systematic manner and should include the search and resolution of the primary causes. Identifying and treating the primary cause of pruritus greatly increases the success rate of any therapy for pruritus.

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.

An update on the treatment of canine atopic dermatitis

Remarkable progress has been made in recent years concerning our understanding of the pathogenesis of canine atopic dermatitis (AD). As our understanding improves, the therapeutic approach evolves. Of utmost importance is the documentation of skin barrier impairment in canine AD: ceramides deficiency leads to increased permeability and increased allergen penetration and sensitization. It is currently unknown whether this dysfunction is primary and genetically inherited or secondary to inflammation but it is accepted that skin barrier deficiency plays an important role in either starting or minimally exacerbating canine AD. Thus, the therapeutic approach has changed from focusing on the control of the inflammation to a combined approach that includes therapies aimed at skin barrier repair. The issue of skin barrier repair has been addressed both with oral administration of essential fatty acids and the topical application of products containing a combination of ceramides and fatty acids. These strategies are most helpful as adjunctive treatments and would be best used in young patients that have not developed chronic skin changes. Importantly, treatment for canine AD is multimodal and tailored to the individual patient, the age, and the duration of the disease. Client education plays an important role in explaining the importance of a long-term approach to minimize flare-ups and, in this context, topical therapy to correct skin barrier can be of great benefit. This is an area still in infancy and much work is needed to identify the best formulation. In human medicine, long-term use of moisturizers can have a profound effect on skin barrier and gene expression of proteins involved in skin barrier. This effect is variable depending on the formulation used. It is reasonable to speculate that the same may be true in dogs; thus, it is very important to identify the correct ingredients and formulation to use.