Treatment of canine atopic dermatitis: 2010 clinical practice guidelines from the International Task Force on Canine Atopic Dermatitis

Contagious yawning and scratching in captive lemurs

Behavioral contagion is thought to play a significant role in social synchronization and coordination across animal taxa. While there is extensive evidence of behavioral contagion in Haplorrhines (i.e. monkeys and apes), limited research exists in Strepsirrhines (i.e. lemurs). Here, we aimed to investigate the presence of contagious yawning and scratching in two captive groups of black-and-white ruffed lemurs (Varecia variegata) (N = 4) and red ruffed lemurs (Varecia rubra) (N = 4), and further test whether behavioral contagion is modulated by the model's social integration in the group. We conducted all occurrence sampling to examine whether individuals observing a yawning or scratching event (i.e. trigger event) were more likely to yawn or scratch in the following 2 min, as compared to individuals who did not observe it. We ran generalized linear mixed models and found that the likelihood of yawning and scratching was higher for subjects observing the trigger event than for subjects who did not observe the event, although the model's social integration had no modulating effect on the probability of showing behavioral contagion. Our findings represent the first evidence of behavioral contagion in this genus and contribute to shed light on the distribution and the possible adaptive function of this phenomenon in primates.

Total protein concentration and stability of Amb a 1 in glycerinated ragweed sublingual immunotherapy stored at room temperature and refrigerated cold temperature

BACKGROUND

Few studies have investigated optimal storage conditions or expiration dates for sublingual immunotherapy (SLIT) formulations prepared from glycerinated allergen extracts.

HYPOTHESIS/OBJECTIVES

The objective of this study was to compare concentrations of short ragweed major allergen (Amb a 1) and total protein in SLIT formulations stored at two different temperatures. It was hypothesised that protein concentrations would show greater decline over time in a formulation stored at room temperature (RT) than in one stored under refrigeration.

MATERIALS AND METHODS

Two SLIT samples containing equal volumes of 20,000 PNU Amb a 1 extract were prepared and stored at refrigerated cold (CT) (2-8°C) or RT (20-24°C) for 140 days. Changes in total protein and major allergen concentration and composition were measured by Bradford assay, two-site enzyme-linked immunosorbent assay and SDS-PAGE. Presence of Amb a 1 was confirmed with Western immunoblot. Data were analysed using an analysis of covariance, with p < 0.05 considered significant.

RESULTS

SDS-PAGE showed compositional changes in a ~26-30 kDa protein band under RT and not CT storage. The Amb a 1 concentration of the RT SLIT sample declined significantly over time, compared to that of the CT SLIT sample (F(1,8) = 47.69, p < 0.0001). There was no significant difference in total protein concentration over time between groups (F(1,8) = 1.79, p = 0.22).

CONCLUSIONS AND CLINICAL RELEVANCE

These results demonstrate that storage of glycerinated SLIT formulations in refrigerated CT preserved the highest concentration of the specific allergen Amb a 1, suggesting that SLIT formulations containing short ragweed should be stored under refrigeration.

Sustained release of stem cell secretome from nano-villi chitosan microspheres for effective treatment of atopic dermatitis

Canine atopic dermatitis (AD) arises from hypersensitive immune reactions. AD symptoms entail severe pruritus and skin inflammation, with frequent relapses. Consequently, AD patients require continuous management, imposing financial burdens and mental fatigue on pet owners. In this study, we aimed to investigate the therapeutic relevance of secretome from canine adipose tissue-derived mesenchymal stem cells (MSCs), especially after encapsulation in nano-villi chitosan microspheres (CS-MS) to expect improved efficacy. Conditioned media (CM) from MSCs significantly inhibited the proliferation of splenocytes, induced the generation of regulatory T cells, and decreased mast cell degranulation. We found that beneficial soluble factors known to reduce AD symptoms, including transforming growth factor-beta 1, were detectable after sequential concentration and lyophilization of CM. The CS-MS, developed by a phase inversion regeneration method, showed high loading and sustained release of the secretome. Local injection of secretome-loaded CS-MS (ST/SC-MS) effectively reduced clinical severity compared to groups treated with secretome. Histological analysis revealed that ST/SC-MS potently suppressed epidermal hyperplasia, immunocyte infiltration and mast cell activation in the lesion. Taken together, this study presents a novel therapeutic approach exhibiting more potent and prolonged immunoregulatory efficacy of MSC secretome for canine AD treatment.

Updated insights into the molecular pathogenesis of canine atopic dermatitis

Atopic dermatitis (AD) is a common and chronic inflammatory skin disease with frequent relapses. The genomics revolution has greatly contributed and revolutionised our knowledge of human AD; understanding the molecular skin fingerprint of AD and associated pathogenic immune pathways has led to preclinical assessments of several novel treatments. Initial studies using microarray analysis to analyse transcriptome (gene expression) changes provided relevant insight on the inflammatory and structural changes occurring at the time of acute or chronic AD skin lesions, or after immunomodulating treatments with drugs ciclosporin and dupilumab, a monoclonal antibody anti-IL4 receptor. The studies revealed that human AD is characterised by the activation of multiple cytokine pathways (predominance of T helper cell [Th]2 with some activation of Th1, Th17 and Th22) as well as dysregulated expression of barrier components in the skin. There are several reports on the expression of different single molecular targets (e.g. interleukin [IL]-13, CCL17 and periostin) in spontaneous canine AD (cAD). However, significant studies of the transcriptome have been limited to a single microarray study analysing chronic AD skin lesions in dogs. While revealing a large number of genes differentially expressed in cAD skin, the small sample size (n = 13 dogs) and the lack of changes in key epidermal barrier and inflammatory cytokine genes in the microarrays have inhibited discussion towards specific immunological changes. This review summarises the current literature regarding the molecular mechanisms of spontaneous cAD, including the recent data regarding RNA sequencing, and compares some pathogenic aspects to the previously published data from human AD.

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

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

A randomised, double-blinded, controlled trial to determine the efficacy of combined therapy of oclacitinib and marine oil extract PCSO-524 in dogs with atopic dermatitis

BACKGROUND

Polyunsaturated fatty acids (PUFA) can be beneficial in the management of canine atopic dermatitis (cAD). A commercial product PCSO-524 containing PUFA has demonstrated anti-inflammatory effects in dogs.

HYPOTHESIS/OBJECTIVES

To evaluate the efficacy of PCSO-524, in combination with oclacitinib in dogs with cAD.

ANIMALS

Seventeen client-owned dogs with cAD.

MATERIALS AND METHODS

A randomised, double-blinded, controlled trial. All dogs were treated with oclacitinib (0.4-0.6 mg/kg) twice a day for 14 days, then once a day until Day (D)42. They were randomly divided into two groups: PCSO-524 (n = 9) and sunflower oil (n = 8). Clinical status was assessed by Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-04) and pruritus Visual Analog Scale (pVAS) at baseline (D0), D14, D28 and D42. Trans epidermal water loss (TEWL) was measured at the same time points.

RESULTS

CADESI scores decreased significantly after treatment and there was a significant difference between the PCSO-524 and the control group at D28 (p = 0.04) and D42 (p = 0.03). The PCSO-524 group also demonstrated a significantly decreased pVAS on D28 and D42 (p < 0.001 and p < 0.001) compared to D0, while significant differences were observed in the control group at D14 and D28 (p < 0.01 and p = 0.04) and not at D42 (p = 0.12). The mean TEWL showed a significant decrease at D28 and D42 in the PCSO-524 group, compared to the control group (p = 0.002 and p < 0.001).

CONCLUSIONS AND CLINICAL RELEVANCE

The combination of PCSO-524 and oclacitinib may help to alleviate the rebound effect that occurs when tapering down the dosage of oclacitinib, as compared to using oclacitinib alone for the management of cAD.

Efficacy and tolerance of a novel topical TRPV-1 channel antagonist in dogs with allergic pododermatitis

BACKGROUND

Pruritus due to allergic skin disease is one of the most common reasons for dermatological consultations in the veterinary clinic. Treatment is usually multimodal and requires continuous monitoring and reassessment. New therapies are needed to broaden the therapeutic arsenal.

HYPOTHESIS/OBJECTIVES

The aim of this study was to evaluate the efficacy of a novel transient receptor potential vanilloid 1 (TRPV1) channel antagonist for allergic pododermatitis in dogs.

ANIMALS

Twenty-four client-owned dogs with allergic pododermatitis.

MATERIALS AND METHODS

The study was an open, prospective, multi-centre clinical trial with client-owned dogs. All dogs were treated twice daily with a spray containing hydroxymethoxyiodobenzyl glycolamide pelargonate for 28 days. Clinical assessments included pruritus Visual Analog Scale (PVAS), pedal skin lesion score, evaluation of quality of life (QoL), presence of secondary infections and a four-point subjective efficacy assessment by the veterinarian and the dog owner.

RESULTS

There was more than 50% improvement in all scores by the conclusion of the study. Secondary infections were reduced (p < 0.001). Both the veterinarians and dog owners evaluated the efficacy of the product positively. The product was well-tolerated.

CONCLUSIONS AND CLINICAL RELEVANCE

This study demonstrated the tolerability and efficacy of a TRPV1 antagonist on pruritic pododermatitis in 24 dogs.

Dermatological evaluation in dogs with atopic dermatitis treated with full-spectrum high cannabidiol oil: a pre study part 1

Introduction

Dermatological consultations represent a great part of the small animal medical clinic routine. Canine atopic dermatitis (CAD) is a common skin disease that affects a significant amount of dogs, making it a relevant consideration in clinical practice. The role of the endocannabinoid system on skin homeostasis has been described and its deregulation contributes to dermatopathies. Its function in specialized skin cells reveals an expressive therapeutic potential. Due to the difficulties and the growing scientific evidence of the therapeutic benefits of cannabis on animals, this work aimed to evaluate the anti-inflammatory effects of cannabis-derived oil in the treatment of CAD.

Methods

Fourteen canines diagnosed with CAD were divided into two groups: T: full spectrum high cannabidiol (CBD) cannabis oil, 2,5 mg/kg; and C: control group (treated with olive oil alone). The effectiveness was evaluated based on the degree of pruritus, dermatological evaluation (CADESI-4) and histopathological evaluation of the skin including mast cell count.

Results

Despite the theoretical basis, there were no significant results obtained between the compared treatments.

Discussion

Thus, it can be concluded that although full spectrum high cannabinoids therapy presents a promising approach to immunological diseases, further research is required in order to establish the actual effective cannabinoid ratio within the myriad possible combinations and for multi-target therapy of CAD.

Alfaxalone provides reliable sedation for intradermal allergen testing in dogs and does not significantly affect results when compared to dexmedetomidine

BACKGROUND

Dexmedetomidine (Dexmedetomidine hydrochloride-Dexdomitor; Zoetis) is the preferred sedative used for canine intradermal allergen testing (IDT) in the United States. Alfaxalone (Alfaxan Multidose; Jurox Animal Health) is a neuroactive steroid, and its effect on sedation and allergen reactivity scores is unknown.

HYPOTHESIS/OBJECTIVES

We hypothesised that alfaxalone would produce an adequate level of sedation with fewer cardiovascular adverse effects and would not affect allergen reactivity scores or histamine wheal size compared to dexmedetomidine.

MATERIALS AND METHODS

Twenty client-owned dogs were included in two groups: 10 atopic and 10 nonatopic. In a randomised, controlled, blinded, cross-over design all dogs underwent two modified IDT, 1-4 weeks apart, using intravenous dexmedetomidine (2.87-5.22 μg/kg) or alfaxalone (1.8-2.4 mg/kg). Anaesthetic parameters and sedation level were recorded over 25 min using a validated canine sedation scale described by Grint et al. (Small Anim Pract, 2009, 50, 62). Simultaneously, both objective and subjective reactivity scores were measured in technical triplicates at 10, 15 and 20 min. The modified IDT included eight allergens, histamine-positive and saline-negative controls.

RESULTS

Alfaxalone produced a significantly higher sedation score across all time points (p < 0.05). All objective scores were significantly correlated to the corresponding subjective scores (Spearman R = 0.859, p < 0.0001). Sedative used did not significantly affect subjective allergen scores for nine atopic dogs (p > 0.05, 15 min). Sedative used did not affect the diameter of objective scores for individual allergens and histamine wheals (p > 0.05, 15 min).

CONCLUSIONS AND CLINICAL RELEVANCE

Intravascular alfaxalone is an alternative sedative for IDT in dogs. Alfaxalone may be preferred to dexmedetomidine in some clinical scenarios as a result of having fewer cardiovascular adverse effects.

High-frequency ultrasound biomicroscopy findings of the skin of dogs with atopic dermatitis

BACKGROUND

The high-frequency ultrasonographic appearance of skin of dogs with atopic dermatitis (cAD) has not been described.

OBJECTIVES

To compare high-frequency ultrasonographic findings among lesional, macroscopically nonlesional skin of dogs with cAD, and the macroscopically nonlesional skin of healthy dogs. Additionally, to determine whether there is any correlation between the ultrasonographic findings in lesional skin and local Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-04) or its domains (erythema, lichenification, excoriations/alopecia). As a secondary aim, six cAD dogs were re-evaluated after management intervention.

ANIMALS

Twenty dogs with cAD (six were re-examined after treatment) and six healthy dogs.

MATERIALS AND METHODS

In all dogs, ultrasonographic examination was performed on the same 10 skin sites, using a 50 MHz transducer. Wrinkling of skin surface, presence/width of subepidermal low echogenic band, hypoechogenicity of dermis and thickness of the skin were evaluated and scored/measured blindly.

RESULTS

Dermal hypoechogenicity was more common and severe in lesional compared to macroscopically nonlesional skin of dogs with cAD. In lesional skin, presence/severity of wrinkling of skin surface and of dermal hypoechogenicity were positively correlated with presence/severity of lichenification, while severity of dermal hypoechogenicity was positively correlated with local CADESI-04. A positive correlation between the change in skin thickness and the change in the severity of erythema during treatment was noted.

CONCLUSIONS AND CLINICAL RELEVANCE

High-frequency ultrasound biomicroscopy may be useful for the evaluation of skin of dogs with cAD and for evaluating the progression of skin lesions during treatment.

Diminished antimicrobial drug use in dogs with allergic dermatitis treated with oclacitinib

Introduction

Dogs with allergic dermatitis often suffer concurrent skin and ear infections. The objective of this study was to retrospectively quantify the number of systemic and topical antimicrobial transactions in dogs with allergic dermatitis, following administration of oclacitinib or a glucocorticoid, compared to dogs that did not receive a pruritus therapy when there is an initial diagnosis of pyoderma. A secondary objective was to demonstrate that dogs on oclacitinib use fewer antimicrobials and concomitant therapies over time and have improved quality of life.

Materials and methods

This was a retrospective case-control study using a large, centralized database to identify canine patients receiving pruritus therapy along with a concurrent diagnosis of pyoderma. For the second objective, 58 client-owned dogs diagnosed with allergic dermatitis were enrolled in a prospective owner and dog quality of life and treatment satisfaction (QoL&TS) study that also evaluated concomitant therapy use over time. In Part A, data consisted of anonymous transaction records from 1,134 hospitals across the United States, representing pyoderma visits between December 2018 and December 2019. Odds ratios comparing the relative odds of having additional antimicrobial agent transactions were calculated, given initial pruritus therapy compared to dogs that did not receive pruritus therapy. Parametric bootstrapping was used to calculate goodness-of-fit statistics. In part B, dogs entered the study on Day 0 and returned for examination on Days 14, 21, 30, and 60. Owner determination of QoL&TS was performed on Days 0, 1, 3, 14, 21, 30, and 60. On Days 0, 14, 21, and 60, a veterinarian assessed concomitant therapies and dermatitis severity scoring. Least Squares Means and Standard Errors for QoL&TS, and Dermatitis Vet VAS (Visual Analog Scale) Scores were calculated using a Linear Mixed Model Approach for Repeated Measures (α = 0.05). The percent reduction in therapies was also calculated.

Results

Dogs that received oclacitinib (n = 5,132) or a glucocorticoid (n = 7,024) had reduced odds (OR: 0.8091; p = 0.0002 and OR: 0.7095; p < 0.0001, respectively) of having a follow up antimicrobial drug transaction after initial antimicrobial therapy compared to dogs with no pruritus therapy at the initial visit (n = 12,997). In part B, oclacitinib demonstrated a statistically significant improvement in QoL&TS scores over time QoL (p < 0.05). Veterinarian assessment showed a 70% reduction in dermatitis severity over time (p < 0.05), supporting oclacitinib's anti-inflammatory effects. Oclacitinib therapy was also associated with an 83% reduction in concomitant treatments, including a 100% reduction in systemic antimicrobial therapy over eight weeks.

Discussion

Dogs receiving oclacitinib showed no increase in antimicrobial therapy transactions compared to glucocorticoid recipients at the initial pyoderma diagnosis. Having a pruritus therapy at the index pyoderma visit reduced the odds of subsequent antimicrobial transactions. In addition to reducing concomitant therapy usage, oclacitinib improved owner and pet QoL, suggesting a paradigm shift in treatment success that could reshape allergic pruritus therapy recommendations. The study provides empirical evidence of oclacitinib's reduction in antibacterial therapy, supporting its therapeutic value and antimicrobial stewardship.

Perception and usage of short-term prednisone and prednisolone in dogs

BACKGROUND

Corticosteroids are widely used with low rates of reported side effects and a broad level of comfort in the hands of most veterinarians. With a low side effect reporting level of < 5% and high level of comfort there may be complacency and underestimation of the impact side effects of corticosteroids may have on a pet and pet owner.

OBJECTIVE

The objective of this clinical study was to describe the experience and perception of an owner who administered anti-inflammatory doses of oral prednisolone and prednisone to their dog for up to 14 days. We hypothesized dogs receiving anti-inflammatory doses of prednisone and prednisolone would experience much greater rates of side effects by day 14 then reported in current literature.

ANIMALS

There were 45 dogs initially enrolled in the study.

RESULTS

At each study point, 31 owners provided results. On day 5, 74% (23/31) reported at least 1 change in their dog's behavior including polyuria, polydipsia, polyphagia, polypnea and/or increased vocalization, with 11 individuals (35%) reporting these changes greatly increased. On day 14, 90% of owners (28/31) reported at least 1 change in their dog's behavior including polyuria, polydipsia, polyphagia, and/or polypnea as the most common changes noted. Overall, 61% (19/31) of owners reported an increase in filling of the water bowl over baseline and one-third (11/31) of pet owners reported cleaning up urinary accidents for pets who had been continent prior to the start of the study. Pet owner steroid satisfaction remained high through day 14 at 4.5/5 (1 = very unsatisfied, 5 = very satisfied).

CONCLUSION

This study highlights the impact short term anti-inflammatory doses of prednisone or prednisolone have on dog behaviour and confirms our hypothesis that by day 14, 90% of dogs experienced one or more behaviour changes, with polyuria and polydipsia most commonly reported. Adverse events were noted regardless of starting dosage or regimen. Although most pet owners expressed satisfaction with steroid treatment due to its high efficacy, 70% would select a more costly treatment if that treatment had fewer side effects.

Canine Mesenchymal-Stem-Cell-Derived Extracellular Vesicles Attenuate Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is associated with systemic inflammation and immune modulation. Previously, we have shown that extracellular vesicles resulting from human adipose-tissue-derived mesenchymal stem cells (ASC-EVs) attenuated AD-like symptoms by reducing the levels of multiple inflammatory cytokines. Here, we aimed to investigate the improvement of canine AD upon using canine ASC-exosomes in a Biostir-induced AD mouse model. Additionally, we conducted in vivo toxicity studies to determine whether they targeted organs and their potential toxicity. Firstly, we isolated canine ASCs (cASCs) from the adipose tissue of a canine and characterized the cASCs-EVs. Interestingly, we found that cASC-EVs improved AD-like dermatitis and markedly decreased the levels of serum IgE, ear thickness, inflammatory cytokines, and chemokines such as IL-4 and IFN-γ in a dose-dependent manner. Moreover, there was no systemic toxicity in single- or repeat-dose toxicity studies using ICR mice. In addition, we analyzed miRNA arrays from cASC-EVs using next-generation sequencing (NGS) to investigate the role of miRNAs in improving inflammatory responses. Collectively, our results suggest that cASC-EVs effectively attenuate AD by transporting anti-inflammatory miRNAs to atopic lesions alongside no toxicological findings, resulting in a promising cell-free therapeutic option for treating canine AD.

Establishment of an Intradermal Canine IL-31-Induced Pruritus Model to Evaluate Therapeutic Candidates in Atopic Dermatitis

Pruritic models in healthy dogs utilizing intravenous administration of interleukin 31 (IL-31) bypass the "natural" itch sensation in AD, which is initiated by pruriceptive primary afferent neurons in the skin. This study aimed to evaluate the immediate/delayed pruritus responses and the pruritic behaviors observed in an intradermal IL-31-induced pruritic model of healthy dogs and the anti-pruritic effect of oclacitinib on said model. In Phase 1, all the dogs were randomized and video-recorded for 300 min after intradermal canine recombinant IL-31 injections (1.75 µg/kg) and vehicle (phosphate-buffered saline) injections. In Phase 2, all the dogs received oral oclacitinib (0.4-0.6 mg/kg, twice daily for 4 consecutive days and once daily on day 5), with the intradermal IL-31 injection performed on day 5. Two blinded investigators reviewed the pruritic behaviors in all the video recordings. Intradermal IL-31 administration to healthy dogs caused a significant increase in the total (p = 0.0052) and local (p = 0.0003) seconds of pruritic behavior compared to the vehicle control. Oral oclacitinib administration significantly reduced the total (p = 0.0011) and local (p = 0.0156) intradermal IL-31-induced pruritic seconds; there was no significant difference in pruritic seconds between the vehicle and oclacitinib within the IL-31 groups. Significant delayed pruritic responses at 150-300 min after IL-31 injections were observed, and intradermal IL-31 failed to induce acute itch (first 30 min). Intradermal injection of IL-31 induces delayed itch responses in dogs that are diminished by the effect of oclacitinib, an oral JAK inhibitor.

Nasal microbiota profiles in shelter dogs with dermatological conditions carrying methicillin-resistant and methicillin-sensitive Staphylococcus species

Dermatological conditions may be complicated by Staphylococcus spp. infections influencing skin and nasal microbiota. We investigated the associations between the resident nasal microbiota of shelter dogs with and without dermatological conditions carrying methicillin-resistant and -sensitive Staphylococcus spp. Nasal sampling of 16 dogs with and 52 without dermatological conditions were performed upon shelter admission (baseline), and then bi-weekly until discharge (follow-up). All samples were cultured for Staphylococcus spp., while 52 samples underwent microbiota analysis. Two elastic net logistic regression (ENR) models (Model 1-baseline samples; Model 2-follow-up samples) were developed to identify predictive associations between dermatological conditions and the variables: signalment, antimicrobial treatment, and nasal microbial genera. Follow-up nasal samples of dogs with dermatological conditions had decreased microbiota diversity and abundance compared to dogs without dermatological conditions. Our ENR models identified predictive differences in signalment and nasal microbial genera between baseline and follow-up samples. Co-occurrence networks showed nasal microbial genera were more dissimilar when comparing dogs with and without dermatological conditions at follow-up. Overall, this study is the first to investigate Staphylococcus spp. carriage effects on nasal microbial genera in a canine animal shelter population, and ultimately reveals the importance of investigating decolonisation and probiotic therapies for restoring nasal microbiota.

Induction of autophagy improves skin and hair conditions in dogs with underlying diseases

Background

Autophagy was reported to play a crucial role in maintaining general and skin health.

Methods

The study used a synthesized autophagy inducer (AI) (Aquatide™ cospharm Inc.; Daejeon, Korea), for evaluating the effects of autophagy on skin and hair in dogs. Twenty-two dogs with poor skin and hair which were diagnosed with canine atopic dermatitis (CAD) or pituitary-dependent hyperadrenocorticism (PDH) were included. Clinical scores using Canine Atopic Dermatitis Extent and Severity Index-04 (CADESI-04), Pruritus Visual Analog Scale (PVAS) and skin barrier function using measurement of transepidermal water loss (TEWL) were evaluated and canine keratinocytes were also used in vitro investigation of pro-inflammatory cytokines after AI treatment.

Results

In the AI group, clinical scores and skin barrier function were improved at week 8 significantly compared to in the other groups. In particular, the AI significantly improved the hair surface damage at 8 weeks compared to the baseline. In vitro, the AI reduced pro-inflammatory cytokines by activating the 78-kDa glucose-regulated protein (GRP78).

Conclusion

AI improve skin barrier function and hair damage and reduce pro-inflammatory cytokines by inhibiting reactive oxygen species (ROS) production in dogs.

Malassezia: Zoonotic Implications, Parallels and Differences in Colonization and Disease in Humans and Animals

Malassezia spp. are commensals of the skin, oral/sinonasal cavity, lower respiratory and gastrointestinal tract. Eighteen species have been recovered from humans, other mammals and birds. They can also be isolated from diverse environments, suggesting an evolutionary trajectory of adaption from an ecological niche in plants and soil to the mucocutaneous ecosystem of warm-blooded vertebrates. In humans, dogs and cats, Malassezia-associated dermatological conditions share some commonalities. Otomycosis is common in companion animals but is rare in humans. Systemic infections, which are increasingly reported in humans, have yet to be recognized in animals. Malassezia species have also been identified as pathogenetic contributors to some chronic human diseases. While Malassezia species are host-adapted, some species are zoophilic and can cause fungemia, with outbreaks in neonatal intensive care wards associated with temporary colonization of healthcare worker’s hands from contact with their pets. Although standardization is lacking, susceptibility testing is usually performed using a modified broth microdilution method. Antifungal susceptibility can vary depending on Malassezia species, body location, infection type, disease duration, presence of co-morbidities and immunosuppression. Antifungal resistance mechanisms include biofilm formation, mutations or overexpression of ERG11, overexpression of efflux pumps and gene rearrangements or overexpression in chromosome 4.

Efficacy of subcutaneous allergen immunotherapy in atopic dogs: A retrospective study of 664 cases

Background

Canine atopic dermatitis (cAD) is an allergic skin disease affecting approximately 10% of dogs. allergen‐specific immunotherapy (ASIT) is currently the only treatment option able to induce tolerance to the causative allergens.

Objective

To retrospectively establish the efficacy of ASIT in atopic dogs.

Animals

Client‐owned (n  = 664) dogs with cAD presented between 2008 and 2018 to two dermatology referral clinics.

Materials and Methods

Clinical records of atopic dogs were reviewed to obtain information including the results of the intradermal skin test and/or allergen‐specific immunoglobulin (Ig)E serological results, the allergens included in the ASIT, concurrent symptomatic medications, and ASIT efficacy after at least 9 months.

Results

Excellent (ASIT alone controlled clinical signs), good (≥50% reduction of clinical signs) and poor (<50% improvement) responses were seen in 31.5%, 28.5% and 40.1% of the dogs, respectively. No significant differences in efficacy were associated with breed, sex, age at initiation of ASIT, type of allergens in ASIT, and between clinics. Dogs re‐examined regularly responded significantly better to ASIT than dogs that did not (>50% improvement in 69.3% and 55.4% of the dogs, respectively). Dogs treated with ASIT and concomitant systemic glucocorticoids showed a significantly poorer response (success rate of >50% improvement of 38.5%).

Conclusions and clinical importance

In 59.9% of atopic dogs, subcutaneous ASIT can improve clinical signs by ≥50%. The beneficial effect of ASIT is higher if dogs are re‐examined regularly and if systemic long‐term corticosteroids are avoided, at least during the first 9 months of ASIT.

The effects of oclacitinib treatment on antimicrobial usage in allergic dogs in primary practice: an Australia wide case-control study

BACKGROUND

Canine allergic dermatitis is a common diagnosis in veterinary practices which can lead to secondary infections requiring treatment with antimicrobials. A previous study suggested that dogs treated with oclacitinib in an Australian referral hospital required fewer courses of antimicrobial therapy compared to dogs receiving other anti-pruritic treatments. This study aimed to quantify the effect of oclacitinib treatment on the use of antimicrobials and other therapies in general practice veterinary clinics across Australia. A retrospective case-controlled review of patient records was designed to investigate the number of courses of antimicrobials and other therapies in dogs that received oclacitinib (Apoquel®), compared with those who received an anti-pruritic treatment that was not oclacitinib.

RESULTS

The target population included canine patients with a presumptive diagnosis of allergic dermatitis presenting between 2008 and 2018 to general practices contributing to the VetCompass Australia database. Patient records of interest were identified using search terms relating to allergic dermatitis, resulting in over 700,000 observations. Multivariable logistic regression models were developed to determine whether cases were prescribed fewer antimicrobial courses than controls, after adjusting for the presence of concurrent skin infections or infectious agents in ears. Our results indicate that fewer antimicrobial courses were prescribed in the cases compared to the controls. After adjusting for the concurrent skin infections, there was a significant reduction in the use of cefovecin [OR:0.62(0.39-0.98), P = 0.043], chlorhexidine [OR:0.57(0.42-0.77), P < 0.001], neomycin [OR:0.4(0.28-0.56), P < 0.001] and amoxycillin clavulanic acid (AMC) [OR: 0.55(0.39-0.78), P = 0.001] in cases compared to controls.

CONCLUSION

This study demonstrates a potential sparing effect of oclacitinib on the prescription of antimicrobials for the treatment of allergic skin diseases in dogs. This information may assist in the planning of treatment for canine allergic dermatitis, with consideration for antimicrobial stewardship.

Multiplex Cytokine Analyses in Ear Canals of Dogs Suggest Involvement of IL-8 Chemokine in Atopic Otitis and Otodectic Mange—Preliminary Results

Simple Summary

Atopic dermatitis is a form of allergy of genetic origin accompanied by itching, during which the animal more easily develops allergies to environmental factors, usually pollen and dust mites. Among the symptoms, otitis is common. The mechanisms of this disease are still not fully understood. In this study, we aimed to demonstrate the detection ability of inflammatory markers (cytokines and chemokines) in the ear canals of atopic dogs suffering from otitis externa compared to healthy dogs and to dogs with parasitic otitis (inflammatory but not allergic otitis). Therefore, we non-invasively sampled the surface of the ear canals of atopic dogs and compared the amounts of certain cytokines and chemokines with those in similar samples taken from ears of healthy dogs and ears with spontaneous ear mite infestation. It appears that concentrations of IL-8 are significantly higher in atopic ears than in healthy ears. Nevertheless, this difference does not appear to be atopic-specific, since the amount of interleukin-8 (IL-8) also increased in ears infested with mites. Further investigations with a larger number of dogs are now required to confirm these results and possibly to find other biomarkers involved in the pathogenesis of canine atopic otitis.

Abstract

Cutaneous cytokines and chemokines are involved in the pathogenesis of human and canine atopic dermatitis. The aim of the present study was to discriminate cytokine expression in the ear canals of atopic dogs with otitis, dogs with non-allergic inflammatory otitis (otodectic mange) and healthy non-atopic dogs. The ear canals of nine atopic dogs suffering from non-infected otitis externa (n = 14 ears), 10 healthy dogs suffering from otodectic mange (n = 20 ears) and 21 healthy controls (39 ears) were swabbed. The concentrations of a panel of 13 cytokines and chemokines on the aural surface were measured by multiplex analyses (Milliplex Canine Cytokine Panel). In addition, Canine Atopic Dermatitis Extent and Severity Index (CADESI)-04 and Otitis Index Score (OTIS3) scores were used to evaluate the overall status of the dogs. The concentration of IL-8 was significantly higher in the ears of atopic dogs and dogs with otodectic mange compared to those of healthy dogs. Significant increases in the levels of IL-10 were also overexpressed in atopic otitis but at lower rates. The concentrations of interleukin(IL)-8 were positively correlated with the OTIS3 hyperplasia score in atopic dogs. Taken together, these results suggest that IL-8 is overexpressed in atopic otitis and otodectic mange and that levels correlate with the otitis severity in atopic dogs.

Investigation on the Effect of Dose, Frequency and Duration of Allergen Exposure on Development of Staphylococcal Infections in a Chronic Model of Canine Atopic Dermatitis

Canine atopic dermatitis (CAD) is chronic and frequently complicated by Staphylococcal infections. Understanding the role of allergen dose, frequency and duration of exposure in triggering infections requires a model. Most models elicit acute inflammation and do not mimic real-life disease. Here we describe the effects of allergen exposures on development of infections in a model of chronic CAD. Diagnosis of pyoderma was based on clinical signs and consistent cytology. Study 1 evaluated the role of duration of exposure keeping the daily dose constant (25 mg/day). The one-week protocol involved three exposures, 3 days in a row. The one-month protocol involved twice-weekly challenges for 4 weeks. The three-month protocol involved twice-weekly challenges for 12 weeks. Study 2 evaluated different daily doses while keeping constant the total weekly dose (25 mg) and duration (3 weeks). Low-dose used 5 mg/day for 5 days, each week. High-dose used 12.5 mg/day twice-weekly. In Study 1, the longer the exposure, the more dogs developed pyoderma (6/9 in the three-month study, 2/9 in the one-month and 0 in the one-week). In Study 2, low-dose daily exposure caused more infections (5/8) than high-dose infrequent exposure (0/8). It is concluded that low-grade, daily exposure for a long time is most relevant for development of staphylococcal infections.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Randomized, double-blind, placebo-controlled clinical trial measuring the effect of a dietetic food on dermatologic scoring and pruritus in dogs with atopic dermatitis

Background

Canine atopic dermatitis (AD) is a common condition that often requires multimodal therapy. Including a diet in the multimodal management of AD may reduce medication doses, saving pet owners money and reducing side effects. The objective of this randomized, double-blind, placebo-controlled clinical trial was to determine if a diet fortified in antioxidants, polyphenols, and omega-3 fatty acids can reduce the clinical signs of AD. Forty client-owned dogs with AD were enrolled in the study and assigned to either an enriched diet (diet B) or control diet (diet A) for 60-days. CADESI-4 index scores and owner-reported pruritus scores were measured periodically.

Results

Total CADESI-4 index scores for dogs eating diet B were lower on day 60 compared to baseline (P = 0.003). There was no statistical difference in scores for dogs eating diet A over a 60-day period. Diet B dogs had 25 and 49% reductions in CADESI-4 index scores on days 30 and 60, respectively (P = 0.0007) while diet A had no change over the study period. When comparing the percent change in owner-reported pruritus scores, diet B also performed better than diet A. By day 60, owners feeding diet B to their dogs reported a significant reduction (P < 0.0001) of 46.4% in itching, while those on diet A reported a 26.8% reduction, which was not statistically significant (P = 0.08).

Conclusions

These study results demonstrate feeding a diet enriched with ingredients to improve skin health and reduce inflammation improves the clinical signs of AD in dogs.

Immunomodulatory effect of long-term oclacitinib maleate therapy in dogs with atopic dermatitis

BACKGROUND

Canine atopic dermatitis (cAD) is a chronic disease characterised by hypersensitivity to environmental allergens. Oclacitinib maleate selectively inhibits pro-inflammatory mediators associated with cAD. However, the impact of chronic oclacitinib use on immunocompetence requires further investigation.

OBJECTIVES

Herein, we examined the potential immunomodulatory effects of prolonged oclacitinib treatment in dogs.

ANIMALS

Thirteen privately owned dogs with cAD, treated with 0.4-0.6 mg/kg oclacitinib for 12 months.

METHODS AND MATERIALS

Pruritus level was evaluated using a pruritus Visual Analog Scale (pVAS) and the canine atopic dermatitis extent and severity index, 4^th iteration (CADESI IV). Peripheral blood samples were collected for routine laboratory assays and lymphocyte subtypes were analysed using flow cytometry. Antigen-specific intracellular cytokine production from CD4+ and CD8+ T lymphocytes was analysed following in vitro stimulation by Dermatophagoides farinae antigens.

RESULTS

Oclacitinib treatment significantly reduced pVAS and CADESI-04 scores, by 51% and 86.7%, respectively. Flow cytometric analysis revealed increased CD4+ and CD14+ lymphocyte populations. The cytokine profile at 360 days after treatment initiation was similar to that before treatment and was not associated with clinical relapse.

CONCLUSION

Oclacitinib, when administered at the currently labelled dose for one year, is associated with a significant increase in circulating CD4+ T cells, but does not alter cytokine production from antigen-stimulated T cells. The results reported do not support evidence for immunosuppression mediated by the mechanisms evaluated in this study.

A novel therapeutic diet can significantly reduce the medication score and pruritus of dogs with atopic dermatitis during a nine month controlled study

Background

Canine atopic dermatitis (cAD) is a common chronic relapsing pruritic skin disease for which management commonly relies on life‐long use of immunomodulatory drugs. A number of the medications used are associated with adverse effects and the potential for complications during long‐term use.

Hypothesis

The goal of the study was to determine if a complete and balanced diet formulated for therapeutic benefit could contribute towards management of cAD. We hypothesised that the diet would reduce pruritus while also reducing the requirement for medication during the study period.

Animals, materials and methods

Forty privately owned dogs, having undergone a comprehensive diagnosis for cAD, were randomly allocated to two groups, each group being fed one of two diets (test or control) for up to nine months. We assessed pruritus, Canine Atopic Dermatitis Extent and Severity Index‐(4th iteration) and medication score, the latter reflecting the medication required to maintain a satisfactory quality of life for the animal.

Results

Both diets were well‐accepted and ‐tolerated. There was a significant improvement in the pruritus score after three months of feeding the therapeutic diet (P = 0.0001). No such improvement was observed at any time point in the group of dogs given the control diet. There was a reduced drug requirement for dogs receiving the therapeutic diet after three months (P = 0.058), and that decrease was significant at six months (P = 0.021) and nine months (P = 0.018). No improvement was seen at any time point in the control group.

Conclusion

The results suggest that a novel therapeutic diet can assist in the management of cAD by helping to control pruritus and reducing reliance on medication.

Multivariable analysis of the influence of cross-reactive carbohydrate determinant inhibition and other factors on intradermal and serological allergen test results: a prospective, multicentre study

BACKGROUND

Serological allergen testing (SAT) is used widely to formulate allergen-specific immunotherapy for atopic dogs. Serum immunoglobulin (Ig)E specific for cross-reactive carbohydrate determinants (CCD) can produce false-positive reactions, creating discrepancy between SAT and intradermal allergen test (IDAT) results.

OBJECTIVES

The primary objective was to determine if inhibition of anti-CCD IgE in a commercial assay improved correlation with IDAT. The secondary objective was to assess the influence of dog- and clinic-specific factors, environmental factors, putative allergen exposure and prior medications on intradermal and SAT reactivity.

ANIMALS

Two-hundred and eleven client-owned dogs were enrolled from eight North American dermatology specialty practices.

METHODS AND MATERIALS

Collection of serum samples and IDAT were performed on the same day. Sera were assayed for detection of IgE specific to 25 allergens, before and after treatment with a proprietary inhibitor of anti-CCD IgE. Data for each dog were collected via a questionnaire filled out by veterinary personnel.

RESULTS

The correlation between the testing modalities was fair before (Spearman's rho, ρ = 0.2092) and after (ρ = 0.3042) inhibition of anti-CCD IgE. Ciclosporin dose (P = 0.003), independent of duration of use, and duration of lokivetmab use (P = 0.001), independent of dose administered, were associated with statistically significant decreases in IgE concentrations across all allergen types.

CONCLUSIONS AND CLINICAL RELEVANCE

Contrary to previous reports, this study demonstrated unchanged correlation between SAT and IDAT after inhibition of anti-CCD IgE. Ciclosporin dose and lokivetmab treatment duration may have unexplored effects on IgE concentration during SAT.

The Association Between the Use of Oclacitinib and Antibacterial Therapy in Dogs With Allergic Dermatitis: A Retrospective Case-Control Study

Background: Canine allergic dermatitis, including atopic dermatitis, often requires antibacterial therapy for concurrent infections. Oclacitinib is indicated for treatment of pruritus associated with allergic dermatitis and the clinical manifestations of atopic dermatitis in dogs aged ≥12 months.

Hypothesis/Objectives: We aimed to determine if there was a quantitative difference in antibacterial use by dogs with allergic dermatitis receiving oclacitinib vs. other anti-pruritic therapies and before vs. after oclacitinib.

Animals: In this retrospective case-control study, cases (n = 58) included dogs suffering from allergic dermatitis aged ≥12 months receiving oclacitinib and controls (n = 205) were counterpart dogs treated with other anti-pruritic therapies.

Methods: Clinical histories of dogs with allergic dermatitis were collected from a small animal university hospital. Multivariable logistic regression models were developed adjusting for underlying skin or ear conditions to determine whether cases were prescribed fewer antibacterials than controls.

Results: The odds of systemic antibacterial usage were lower in cases vs. controls [odds ratio (OR): 0.29 (95% confidence interval 0.12–0.71); P = 0.007]. The odds of amoxycillin clavulanic acid usage (12.5–25 mg/kg orally every 12 h) was lower in cases vs. controls [OR: 0.08 (0.01–0.71); P = 0.024]. Topical antibacterial drug use was reduced overall; however, only the odds of neomycin use was lower in cases vs. controls [OR: 0.3 (0.1–0.89); P = 0.029]. Cases had higher odds of experiencing improvements in allergic dermatitis categories vs. controls [OR: 7.89 (3.26–19.13); P < 0.001].

Conclusions and Clinical Importance: Our results suggest that use of oclacitinib to treat allergic dermatitis in dogs is associated with less antibacterial use than other anti-pruritic therapies.

A proposed medication score for long-term trials of treatment of canine atopic dermatitis sensu lato

BACKGROUND

The use of concurrent medications is necessary in trials of treatment of canine atopic dermatitis. Our aim was to use the best available evidence to construct and then to validate a medication score (MS) formula that will estimate the impact of concurrent medications on trial outcomes.

METHODS

Trials of 15 interventions were scrutinized to find those that were consistent in terms of specific medication, administration route and dosage regimen. A MS was constructed in five steps, starting from assigning a score of 1 for each day on oral prednisone, prednisolone or methylprednisolone at 0.5-1.0 mg/kg. The MS score was validated using the clinical records of 35 dogs with atopic dermatitis that had been treated for a period of 12 ± 2 weeks with six of these medications and compared with a previously published non-validated MS.

RESULTS

A MS could be assigned to eight treatments, six of which had been administered to the 35 dogs. A positive correlation was seen with the previously published MS and a negative correlation with changes in lesional and pruritus scores.

CONCLUSION

This MS may be a useful tool in new studies evaluating the efficacy of treatments in canine atopic dermatitis.

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.

A descriptive study of allergen-specific IgE serological tests for canine atopic dermatitis in Thailand

Background

This study describes the usefulness of allergen-specific Immunoglobulin E (IgE) serology (ASIS) for identifying allergens in dogs with atopic dermatitis. ASIS tests were conducted in 23 dogs diagnosed with atopic dermatitis for indoor allergens (yeast and mites), outdoor allergens (grass pollen, weed pollen, and tree pollen), and fleas. The relationship among positive ASIS tests were determined using Pearson’s correlation coefficient (r).

Results

Of the atopic dogs, 26.09%, 4.35%, and 47.83% had positive ASIS tests for only indoor allergens, only outdoor allergens, and both indoor and outdoor allergens, respectively. The prevalence of positive ASIS tests was highest for mites (69.57%) and did not differ between indoor and outdoor allergens by age, breed, or sex. The prevalence of positive ASIS tests for indoor allergens during the rainy season (84.21%) was significantly higher than during winter (25.00%, P-value = 0.030). The correlation coefficient of the ASIS results among the outdoor allergens indicated a strong correlation between grass and tree pollen (r = 0.840, P-value < 0.01), grass and weed pollen (r = 0.812, P-value < 0.01), and tree and weed pollen (r = 0.714, P-value < 0.01). The correlation coefficient of the ASIS results of D. farinae indicated a strong correlation with A. siro (r = 0.951, P-value < 0.01) and a moderate correlation with B. tropicalis (r = 0.656, P-value < 0.01) and T. putrescentie (r = 0.672, P-value < 0.01).

Conclusions

ASIS tests are useful in screening for multiple allergens in dogs with atopic dermatitis. Dust mites are an important source of indoor allergens and may be responsible for a higher titer of IgE antibodies against indoor allergens during the rainy season.

A survey of primary care practitioners' referral habits and recommendations of allergen-specific immunotherapy for canine and feline patients with atopic dermatitis

BACKGROUND

A recent pilot study of primary care veterinarians' attitudes regarding canine atopic dermatitis and initiation of allergen-specific immunotherapy (ASIT) revealed several barriers to specialist referral (in the USA) and use of ASIT as a treatment modality.

HYPOTHESIS/OBJECTIVES

The primary objective was to collect data on referral habits and ASIT practices among a much larger cohort of primary care veterinarians located around the world, and to explore barriers to referral and management of atopic diseases of dogs and cats with ASIT.

METHODS AND MATERIALS

An online survey, administered through the Veterinary Information Network (VIN, Davis, CA, USA), asked participants to self-report their referral habits and immunotherapy recommendations, and rate barriers and motivating factors using Likert-scale responses.

RESULTS

Of 827 survey responses, 97.6% identified as primary care practitioners. A larger number of practitioners (84.5%) reported seeing atopic dogs often, compared with atopic cats (9.7%). Fewer of these veterinarians (56.6%) referred atopic cats for specialist care, compared to atopic dogs (73.5%). Timely communication, sharing long-term management of the case, and provision of local continuing education were identified as factors associated with increased willingness to refer. A higher proportion of practitioners reported recommending ASIT for dogs (44.3%) than for cats (16.0%). Only 56.0% of respondents considered success rates of ASIT to be acceptable, while 27.9% were neutral on the topic.

CONCLUSIONS AND CLINICAL RELEVANCE

Dermatology specialists might build stronger relationships with referring veterinarians through timely case follow-up and provision of continuing education regarding the long-term benefits of ASIT and symptomatic management practices.

Efficacy and safety of 0.0584% hydrocortisone aceponate topical spray and systemic oclacitinib combination therapy in dogs with atopic dermatitis: a randomized, double-blinded, placebo-controlled trial

BACKGROUND

Oclacitinib is an effective systemic therapy for dogs with atopic dermatitis (AD). Few studies have evaluated concurrent topical treatment with oclacitinib in dogs.

OBJECTIVES

To evaluate the efficacy and safety of combination therapy of oclacitinib and 0.0584% hydrocortisone aceponate (HCA) spray in dogs with AD.

ANIMALS

Eighteen dogs with AD.

METHODS AND MATERIALS

This study was a randomized, double-blinded, placebo-controlled trial. All dogs were treated with oclacitinib (0.4-0.6 mg/kg twice daily for 14 days, then once daily for 14 days) and randomized to receive either HCA spray or placebo spray, applied once daily for seven days then every other day through to Day (D)28. Clinical assessments included the Canine Atopic Dermatitis Extent and Severity Index, 4^th iteration (CADESI-4) and the pruritus Visual Analog Scale (PVAS) every seven days, and blood and urine tests every 14 days.

RESULTS

The mean CADESI-4 and PVAS scores were significantly reduced on D7 and D14 compared to D0 in both groups (P < 0.05). From D14 to D21, CADESI-4 and PVAS scores were significantly increased in the placebo group (P < 0.005), and not in the HCA-treated group. The mean reduction from baseline of the HCA-treated group was significantly higher than that of the placebo group for the PVAS and CADESI-4 on D21 (59.9% versus 27.6%, P = 0.0216) and D28 (56.0% versus 30.5%, P = 0.0109), respectively. One dog in the HCA-treated group was withdrawn as a consequence of developing diarrhoea.

CONCLUSION

Topical application of 0.0584% HCA spray may be useful for preventing exacerbation of pruritus and clinical lesions when tapering oclacitinib therapy in dogs with AD.

Allergen-specific immunotherapy in dogs with atopic dermatitis: is owner compliance the main success-limiting factor?

BACKGROUND

While the efficacy of allergen-specific immunotherapy (ASIT) to treat canine atopic dermatitis has been well established, it remains unclear why not all dogs show the same response to treatment. The goal of the study was to determine the relationship between duration of ASIT and two measurements of success: disease severity and concomitant medication sparing effect.

METHODS

Data were retrospectively compiled for 145 dogs with atopic dermatitis treated with ASIT. As a measure of treatment compliance, cases were stratified into dogs treated for less than 12 months or for at least 12 months. Treatment efficacy, defined as a reduction in disease severity score (scale 0-10), was compared between both groups, and correlations between treatment success and several related factors were examined.

RESULTS

ASIT treatment duration was strongly correlated with treatment efficacy. Animals treated for less than 12 months showed lower efficacy rates (22 per cent) than those treated for at least 12 months (65 per cent). Further, in animals treated for at least 12 months, concomitant medications were reduced more (87 per cent) than in animals treated for less than 12 months (39 per cent).

CONCLUSION

A lack of owner compliance emerged as the main factor explaining the reduced effectiveness of ASIT. To improve treatment adherence, veterinarians and owners need to be better informed about ASIT mechanisms of action before starting treatment.

Biology, diagnosis and treatment of Malassezia dermatitis in dogs and cats Clinical Consensus Guidelines of the World Association for Veterinary Dermatology

BACKGROUND

The genus Malassezia is comprised of a group of lipophilic yeasts that have evolved as skin commensals and opportunistic cutaneous pathogens of a variety of mammals and birds.

OBJECTIVES

The objective of this document is to provide the veterinary community and other interested parties with current information on the ecology, pathophysiology, diagnosis, treatment and prevention of skin diseases associated with Malassezia yeasts in dogs and cats.

METHODS AND MATERIAL

The authors served as a Guideline Panel (GP) and reviewed the literature available prior to October 2018. The GP prepared a detailed literature review and made recommendations on selected topics. The World Association of Veterinary Dermatology (WAVD) Clinical Consensus Guideline committee provided guidance and oversight for this process. The document was presented at two international meetings of veterinary dermatology societies and one international mycology workshop; it was made available for comment on the WAVD website for a period of six months. Comments were shared with the GP electronically and responses incorporated into the final document.

CONCLUSIONS AND CLINICAL IMPORTANCE

There has been a remarkable expansion of knowledge on Malassezia yeasts and their role in animal disease, particularly since the early 1990's. Malassezia dermatitis in dogs and cats has evolved from a disease of obscurity and controversy on its existence, to now being a routine diagnosis in general veterinary practice. Clinical signs are well recognised and diagnostic approaches are well developed. A range of topical and systemic therapies is known to be effective, especially when predisposing factors are identified and corrected.

Supplementation with eicosapentaenoic acid and linoleic acid increases the production of epidermal ceramides in in vitro canine keratinocytes

BACKGROUND

Few studies have investigated the effects of essential fatty acids on the production of epidermal ceramide (CER) in canine keratinocytes.

HYPOTHESIS/OBJECTIVES

To investigate the effects of eicosapentaenoic acid (EPA) and linoleic acid (LA) supplementation on the production of CERs using an in vitro canine keratinocyte culture system.

METHODS AND MATERIALS

Canine keratinocyte cells (MSCEK) were incubated with high Ca²⁺ [1.8 mM calcium chloride (CaCl₂ )] serum-free medium, supplemented with 3 µM EPA and 15 µM LA when the cells showed confluency. On Day 8 of application, lipid analysis using high-performance thin layer chromatography and real-time PCR for detecting glucosylceramide synthase and ceramidase were performed.

RESULTS

It was revealed that the amounts of CER (EOS) (combination of ω-hydroxy fatty acids and sphingosines), CER [EOP] (combination of ω-hydroxy fatty acids and phytosphingosines) and a mixture of CER [NS] (combination of nonhydroxy fatty acids and sphingosines) and [NDS] (combination of nonhydroxy fatty acids and dihydrosphingosines), as well as total CERs, were significantly increased in cells incubated with EPA and LA compared to those of the vehicle, with increased mRNA expression of glucosylceramide synthase.

CONCLUSIONS AND CLINICAL IMPORTANCE

These findings suggest that EPA and LA can potentially alter the CER profile of the skin and this may contribute to its epidermal barrier function in canine skin.

Detection of allergen-specific antibody-secreting cells in dogs by ELISPOT

Current laboratory tests are unable to distinguish healthy from allergic dogs. Unlike serum antibody responses, circulating antibody-secreting cells (ASC) are temporarily induced after each contact with the antigen. These ASC can be identified using ELISPOT and the observation of allergen-specific ASC might correlate with the causative allergens in dogs with an allergic dermatitis. In this study, blood was sampled from six privately-owned allergic dogs and six non-allergic laboratory beagles to determine the frequency of circulating allergen-specific ASC for common allergens. Blood IgE+, IgA + and IgG + cells were magnetically isolated to determine the number of allergen-specific ASC with ELISPOT for Dermatophagoides farinae, Dermatophagoides pteronyssinus, Alternaria alternata, birch, timothy grass, wheat, cow's milk, bovine, chicken and lamb meat. For IgA and IgG, allergen-specific spots were observed, however for IgE, no spots were detected for any of the allergens. ELISPOT could not differentiate allergic from non-allergic dogs. When the responses to the different allergens were compared, more IgA ASC for D. pteronyssinus were observed compared to some of the other allergens which was statistically significant for the non-allergic dogs and approached significance in the allergic dogs. These findings indicate that ELISPOT can be used to identify circulating allergen-specific IgA- and IgG-secreting cells. The technique did however not detect allergen-specific IgE ASC and was unable to distinguish allergic from non-allergic dogs. Only a small number of studies have studied allergen-specific IgA in dogs. The finding that dogs have higher numbers of D. pteronyssinus-specific IgA ASC points out that apart from IgE and IgG, it might be interesting to include IgA measurements for certain allergens to analyse the complete spectrum of both the protective and pro-allergic antibody responses.

A moisturizer formulated with glycerol and propylene glycol accelerates the recovery of skin barrier function after experimental disruption in dogs

Background

Moisturizers are foundational therapies for human atopic dermatitis. In veterinary medicine, the use of moisturizers has been recommended by an expert committee to alleviate skin dryness that would occur, for example, in canine atopic dermatitis (cAD). However, little is known regarding the effects of moisturizers on the skin barrier.

Hypothesis/Objectives

To investigate the effects of a moisturizer on skin barrier recovery in a canine model of chronic mechanical barrier disruption.

Animals

Six healthy beagle dogs maintained in a laboratory setting.

Methods and materials

A model of chronic skin barrier disruption was simulated by tape stripping on both sides of the thorax. The moisturizer then was applied twice daily for one week to one side of the thorax, while the other hemithorax was left untreated. The effects were evaluated by measurement of transepidermal water loss (TEWL) at various times during skin barrier recovery, and by histological assessment of the disrupted skin one week after moisturizer application.

Results

Overall, TEWL was reduced, epidermal thickness was lower, stratum corneum thickness was greater and the intensity of the dermal inflammatory infiltrate was reduced for treated sites.

Conclusions and clinical importance

These results suggest a potential benefit of the moisturizer for improving skin barrier function, which is frequently altered in chronic inflammatory dermatoses such as cAD.

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

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

IgE sensitivity to Malassezia pachydermatis and mite allergens in dogs with atopic dermatitis

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

Safety and efficacy of a novel oral chewable combination tablet containing sarolaner, moxidectin and pyrantel (Simparica Trio™) against natural flea infestations in client-owned dogs in the USA

BACKGROUND

One randomized, controlled clinical field study was conducted in 18 general veterinary practices throughout the USA to evaluate the safety and efficacy of a novel oral chewable combination tablet, Simparica Trio™, containing sarolaner, moxidectin and pyrantel for the treatment and prevention of fleas on dogs.

METHODS

Client-owned dogs, from households of three or fewer dogs were eligible for enrollment. Four hundred and twenty-two dogs from 251 households were enrolled. Households were randomly assigned in a 2:1 ratio to treatment with either Simparica Trio™ at the minimum label dose of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5 mg/kg pyrantel (as pamoate salt) or afoxolaner (NexGard®, Boehringer-Ingelheim) at the label dose. One dog per household was selected as the primary dog for efficacy evaluations. Treatments were dispensed and dogs were dosed in their home environment on Day 0 and on approximately Day 30. Flea counts and examination for clinical signs of flea allergy dermatitis (FAD) were performed at the initial visit the day before or on Day 0 prior to treatment and on Days 30 and 60. Additionally, all dogs were examined for general health at each visit and blood and urine were collected for clinical pathology at screening and Day 60.

RESULTS

Simparica Trio™ reduced geometric mean live flea counts by 99.0% by Day 30 and by 99.7% by Day 60. As a result of the rapid reduction in flea infestations, clinical signs associated with FAD substantially improved following treatment. Simparica Trio™ was well-tolerated and a diverse range of concomitant medications were administered to dogs during the course of the study. Simparica Trio™ chewable tablets were well-accepted by dogs, with the majority of flavored chewable tablets (91.9%) voluntarily consumed by free choice without, or when offered in food.

CONCLUSIONS

Simparica Trio™ administered orally once monthly for two consecutive treatments was safe and effective against natural flea infestations and substantially improved clinical signs associated with FAD in client-owned dogs in a field study conducted in the USA.

Associations between neutering and early-onset urinary incontinence in UK bitches under primary veterinary care

OBJECTIVES

To investigate association between neutering and early-onset urinary incontinence in bitches under primary veterinary care in the UK.

MATERIALS AND METHODS

A retrospective cohort study of bitches within VetCompass born between January 1, 2010 and December 31, 2012 that were followed until March 31, 2018. The clinical records were automatically searched and manually validated for incontinence cases. Incidence risk and rate over the study period were calculated. Cox regression modelling separately evaluated the hazard of urinary incontinence and association with neutering: (1) from the date of birth for all bitches, both neutered and entire; and, (2) from the date of neutering for the neutered subset. Other variables considered included breed, bodyweight and veterinary practice group.

RESULTS

Overall, 492 bitches were identified with early-onset urinary incontinence from a total of 72,971 included in the study period. Incidence risk was 0.68% (95% confidence intervals 0.62 to 0.74), while incidence rate increased with age. After accounting for confounding factors, increased hazard of early-onset urinary incontinence was identified in: (1) neutered bitches, with the effect increasing with age; and, (2) bitches neutered before 6 months, within the first 2 years following neutering. In both models, increased hazard was additionally associated with increasing bodyweight and breed.

CLINICAL SIGNIFICANCE

Neutering itself and early-age neutering (<6 months) are major risk factors for early-onset urinary incontinence. These results should be taken into account in making evidence-based recommendations on neutering and its timing.

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

Aim

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

Materials and Methods

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

Results

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

Conclusion

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

Noninvasive evaluation of vascular endothelial growth factor-A (VEGF-A) protein concentrations in the stratum corneum and serum of healthy and atopic dogs

BACKGROUND

Vascular endothelial growth factor (VEGF) is a cytokine involved primarily in angiogenesis. In human atopic dermatitis (AD), VEGF has been detected in the stratum corneum and blood.

OBJECTIVE

To evaluate VEGF-A expression in the serum and stratum corneum of healthy and atopic dogs, and its possible correlation with disease severity in atopic dogs.

ANIMAL

Fifteen atopic and 15 healthy, privately owned dogs.

METHODS AND MATERIALS

The severity of clinical signs associated with AD was evaluated with the Canine Atopic Dermatitis Extent and Severity Index (CADESI-04). For all dogs, a single blood sample was performed and serum collected. Tape stripping (15 times) was performed on the left periocular area (lesional skin). A commercially available canine-specific VEGF-A enzyme-linked immunosorbent assay was performed with all samples.

RESULTS

Vascular endothelial growth factor-A was undetectable in the serum. In the stratum corneum, there was no significant difference in VEGF-A concentrations between healthy (mean 89.4 ± 59.5 pg/ml) and atopic dogs (mean 100.3 ± 77.1pg/ml) (P = 0.71). There was no correlation between stratum corneum VEGF-A concentrations and CADESI-04 scores.

CONCLUSIONS AND CLINICAL IMPORTANCE

The role of VEGF in canine AD is unclear. Because of many variants, VEGF-C and VEGF-D or VEGF-A isotopes should be explored in the skin to better evaluate the role of VEGF in canine atopy. Full-thickness skin biopsy, molecular biology and histopathological investigation may be necessary to further assess cutaneous VEGF expression.

Non-controlled, open-label clinical trial to assess the effectiveness of a dietetic food on pruritus and dermatologic scoring in atopic dogs

BACKGROUND

Canine atopic dermatitis (AD) is a common skin disease. The goal of this study was to evaluate food designed to improve skin barrier function and lower inflammation to reduce pruritus and clinical severity in client-owned atopic dogs. The food contained an antioxidant blend to reduce oxidative stress, plant polyphenols to stabilize mast cells, and polyunsaturated fatty acids to improve skin health and reduce inflammation.

RESULTS

Seventeen dogs were included in the analysis. Initially 48 adult atopic dogs were enrolled and exclusively fed a dermatologic food for 8 weeks in a non-controlled, open-label study. Thirty-one dogs were excluded for the following reasons: oral and topical medication changes (n = 17), missing data (n = 4), fatty acid supplementation (n = 3), food refusal (n = 3), dropped out (n = 3), and owner concerns (n = 1). Using a scale from 0 (normal) - 4 (severe), veterinarians evaluated the presence and severity of clinical signs of atopy at weeks 0, 4, and 8. Pet owners also rated their pet's clinical signs of atopy on a scale from 0 (not present) - 10 (present continuously) at weeks 0, 4, and 8. Compared with initial baseline scores (median 19, range 3-69), the total veterinarian scores were significantly lower at weeks 4 (median 11, range 1-15) and 8 (median 7, range 3-46) (p < 0.05). Similarly, owner assessments showed significant improvements in the least squares mean (LSM) from baseline to 4 weeks (itching, redness, licking, and scratching) continuing to 8 weeks (itching, redness, and scratching) (p < 0.05).

CONCLUSIONS

In this open, non-controlled study evaluating a dermatologic diet in seventeen client-owned dogs, owner and veterinarian assessments showed statistically significant reductions in clinical scores designed to measure severity of atopic dermatitis. While these results show promise for the management of canine atopic dermatitis, controlled clinical trials are also needed to affirm our findings.