Dermatitis In Dogs Research Articles

In-vitro Antifungal Susceptibility of Malassezia Dermatitis in Dogs

Malassezia dermatitis is a highly pruritic type of dermatitis which mainly produces itching, erythema as its primary skin lesion and secondary skin lesions includes scaling, seborrhoea, maldour, lichenification and hyperpigmentation. The present study was conducted to compare the antifungal efficacy of Ketoconazole, Itraconazole, and Terbinafine against Malassezia spp. and to evaluate the antifungal sensitivity of Malassezia species isolated from dermatitis cases in dogs in and around Jabalpur, Madhya Pradesh. A total of 100 skin swabs were collected from dogs with dermatological symptoms suggestive of Malassezia spp., out of which 87 swabs were successfully isolated and showed good growth on Sabouraud’s Dextrose Agar (SDA) during primary isolation from the skin swabs. For this, commercially available antifungal discs of Ketoconazole and Itraconazole were used whereas for Terbinafine antifungal disc was made due to lack of its availability. Based on in-vitro antifungal susceptibility studies, it can be concluded that Ketoconazole, Itraconazole, Fluconazole and Terbinafine were found to be effective against Malassezia dermatitis and can be advocated as the drug of choice for the treatment of Malassezia dermatitis in dogs.

Short-term parenteral infusions with high-osmolality amino acid solutions can be safely administered through peripheral catheters in dogs treated for hypoaminoacidemia-related conditions.

To compare complications between central and peripheral administration of high-osmolarity (approx 700 to 1,000 mOsm/L) amino acid (± lipid) infusions. 18 client-owned dogs diagnosed with aminoaciduric canine hypoaminoacidemic hepatopathy syndrome or superficial necrolytic dermatitis receiving parenteral amino acid ± lipid infusions. In this retrospective case series, medical records were reviewed for administration route (central vs peripheral), catheter details and infusion characteristics (product osmolarity, concurrent lipid administration, infusion volume, duration, and rate), and complications for each infusion. 18 dogs received 277 infusions (median, 8.5; range, 1 to 84). Effective infusion osmolarities were 683 mOsm/L in 22% of infusions, 791 mOsm/L in 8%, 802 mOsm/L in 2%, 837 mOsm/L in 45%, and 998 mOsm/L in 23% (65% peripheral, 35% central). Most (n = 230 [83%]) infusions were given peripherally. The osmolarities of solutions administered by each route (P = .53), the infusion rate indexed to body weight (P = .17), or the lipid infusion rates indexed to body weight (P = .89) did not differ. One dog suffered 2 complications in 63 infusions-1 mild, 1 severe-both occurring with peripheral infusions. Thus, the overall complication rate was 2 of 277 (0.9%) infusions. Short-term peripherally administered amino acid ± lipid infusions < 1,000 mOsm/L confer little risk compared to centrally administered infusions. Additional studies are needed to determine the safety of infusions with longer durations. Due to the relative ease of peripheral catheterization, clinicians should consider this route for medically managing aminoaciduric canine hypoaminoacidemic hepatopathy syndrome and superficial necrolytic dermatitis in dogs.

Oclacitinib (APOQUEL®) is a selective Janus kinase 1 inhibitor with efficacy in a canine model of flea allergic dermatitis.

Oclacitinib is a novel Janus kinase (JAK) inhibitor that potently inhibits JAK1-dependent cytokines involved in allergy, inflammation, and pruritus (IL-2, IL-4, IL-6, IL-13, and IL-31). Oclacitinib (Apoquel®, Zoetis Inc, Parsippany, NJ) is approved for the treatment/control of pruritus associated with allergic dermatitis and treatment/control of clinical manifestations of atopic dermatitis in dogs at least 12 months of age. To evaluate the effectiveness of oclacitinib in dogs with flea allergy dermatitis, the JAK1 selective inhibitor was tested in a placebo-controlled, masked, single-dose (0.4 mg/kg) or repeat-dose (0.4 mg/kg, twice daily for 2 weeks) study. Pruritic behaviors were quantitated by video recording, and erythema and skin lesions were assessed using a 10-cm visual analog scale (VAS). Results showed that oclacitinib reduced pruritus by 61% as early as 1.5 h after a single oral dose compared to placebo, with an average reduction (compared to placebo) of 85% 1-5 h after dosing (0.4 mg/kg; p < .0001). Oclacitinib also significantly reduced erythema (p < .0001) and skin lesion (p < .0005) VAS scores on Day 14 compared to placebo in a repeat dose study. No adverse events were noted during the conduct of these studies. IL-31 concentrations were elevated in the majority of dogs after flea infestation, suggesting JAK1-dependent cytokines may drive clinical signs of flea allergy dermatitis. These findings show that oclacitinib, an inhibitor of JAK1-dependent cytokines involved in allergy and inflammation can rapidly reduce clinical signs associated with flea allergic dermatitis in dogs.

Effect of Bacillus subtilis and Bacillus coagulans spores on induced allergic contact dermatitis in dogs.

Probiotic strains have the potential to modulate immune responses, reduce intestinal inflammation, normalize intestinal mucosal function and decrease allergic reactions. This study aimed to investigate the effect of oral probiotic supplements containing Bacillus subtilis and Bacillus coagulans spores on clinical symptoms, haematological factors and immune responses to allergic contact dermatitis in dogs induced by dinitrochlorobenzene (DNCB). DNCB was injected subcutaneously into the scapular region of 20 healthy adult dogs of both sexes, divided into four groups, to induce experimental allergic contact dermatitis. Dogs in Group 1 received food without probiotics or medication. Oral prednisolone was administered to Group 2 for 30 days at a dosage of 0.25mg/kg every other day. The dogs in Group 3 were treated with a combination of oral prednisolone and probiotics. The dogs in Group 4 were fed daily with a mixture of 109 B. subtilis and B. coagulans bacteria for 30 days. The immune system responses and related gene expression were analysed in the treated animals. The administration of probiotics for 30 days resulted in a reduction in clinical symptoms and duration of wound repair. The probiotics treatment also significantly increased the serum bactericidal effects against Staphylococcus aureus and Escherichia coli. It enhanced both the classic and alternative activity of the complement, as well as lysozyme activity. Additionally, the probiotics led to higher total immunoglobulin levels and significant reductions in anti-trypsin and C-reactive protein levels. Furthermore, the expression of IgE, induction of interferon-gamma and IL-4 genes were also reduced. According to the results, B. subtilis and B. coagulans can be further investigated as a viable alternative to corticosteroids in treating allergic contact dermatitis in dogs.

Dog Owners' Perceptions of the Convenience and Value of Chewable Oclacitinib: Quantitative Survey Data from an International Survey.

Oclacitinib is an oral therapy indicated for pruritus associated with allergic or atopic dermatitis in dogs. This study sought to assess pet owners' perceptions of the relative convenience and value of the conventional film-coated formulation and the chewable formulation. A quantitative discrete-choice experimental methodology was applied, comparing (conventional, film-coated) oclacitinib versus chewable oclacitinib using unbranded treatment profiles. Initially, a qualitative interview phase with pet owners and veterinarians was conducted to develop detailed treatment profiles. Subsequently, pet owners participated in a quantitative survey. Overall, 1590 pet owners provided survey responses. Most respondents (62%) reported having experienced challenges administering tablet-based therapies to their dog(s). Half of all respondents (52%) had experience administering flavoured or chewable tablets to their dog. Comparing oclacitinib and chewable oclacitinib (with or without associated costs), the majority of the respondents preferred the chewable formulation in all regions across short-term and long-term scenarios (≥58%; all p < 0.05). The current research is one of few survey-driven studies for treatment preferences in companion animal medicine. Veterinarians may offer chewable or palatable treatment options where available, with potential positive impacts on convenience, compliance, outcomes, quality of life, and the human-animal bond.

Antifungal activity of azoles, allylamines, and 8-hidroxiquinolines, alone and in combination, against Malassezia pachydermatis in vitro and in vivo

Malassezia pachydermatis is often reported as the causative agent of dermatitis in dogs. This study aims to evaluate the in vitro and in vivo antifungal activity of azoles and terbinafine (TRB), alone and in combination with the 8-hydroxyquinoline derivatives (8-HQs) clioquinol (CQL), 8-hydroxyquinoline-5-(n-4-chlorophenyl)sulfonamide (PH151), and 8-hydroxyquinoline-5-(n-4-methoxyphenyl)sulfonamide (PH153), against 16 M. pachydermatis isolates. Susceptibility to the drugs was evaluated by in vitro broth microdilution and time-kill assays. The Toll-deficient Drosophila melanogaster fly model was used to assess the efficacy of drugs in vivo. In vitro tests showed that ketoconazole (KTZ) was the most active drug, followed by TRB and CQL. The combinations itraconazole (ITZ)+CQL and ITZ+PH151 resulted in the highest percentages of synergism and none of the combinations resulted in antagonism. TRB showed the highest survival rates after seven days of treatment of the flies, followed by CQL and ITZ, whereas the evaluation of fungal burden of dead flies showed a greater fungicidal effect of azoles when compared to the other drugs. Here we showed for the first time that CQL is effective against M. pachydermatis and potentially interesting for the treatment of malasseziosis.

Establishment of an experimental model of ovalbumin-induced atopic dermatitis in canines.

A reliable standard model is required to evaluate the efficacy of new drugs for companion animals, especially dogs. Canine atopic dermatitis (cAD), also known as allergic inflammatory skin disease, is a common condition. Currently, the house dust mite animal model is used in the research of cAD; however, this model exhibits significant individual variation and is difficult to standardize. In this study, we used ovalbumin as an antigen to sensitize and stimulate dogs, thereby establishing a stable model mimicking the T-helper 2 (Th2) response seen in cAD. Our objective was to create a cAD model that could be employed to evaluate the efficacy of novel drugs and mimic the Th2 dominant allergic response observed in the pathogenesis of atopic dermatitis of dogs. In this study, six beagles were used. Normal saline was applied to two animals, and ovalbumin to four, on their dorsal skin. The ovalbumin-treated groups exhibited clinical cAD symptoms, such as pruritus and erythema. Moreover, plasma levels of the cAD markers immunoglobulin E and CCL17 chemokine were higher in the ovalbumin-treated group than in the vehicle control group. The skin thickness of the epidermis was significantly increased in the ovalbumin-treated group, with infiltration of inflammatory cells observed in the thickened dermis region. In conclusion, treatment of canine skin with an optimal concentration of ovalbumin induced typical cAD-like symptoms, and histological and molecular analyses confirmed an enhanced Th2-related immune response. Therefore, we successfully established a suitable Th2-dominant response mimicking cAD, which will facilitate targeted research of atopic dermatitis in dogs.

Incidence of fungal dermatitis in dogs

Incidence of fungal dermatitis in dogs

A review of cutaneous hypersensitivity reactions in dogs: A diagnostician's guide to allergy.

Allergic dermatoses are common in people and domestic animals. Resultant lesions are routinely biopsied and submitted for histological examination to confirm a diagnosis or rule out diseases with overlapping or atypical clinical features. Diagnostic pathologists and clinicians are often faced with the difficult task of determining whether an allergic reaction pattern is present on both the microscopic and macroscopic levels and correlating histopathologic findings with clinical and historical data to achieve a precise clinical diagnosis. The bulk of the current veterinary literature on allergic dermatoses focuses on atopic dermatitis in dogs, distantly followed by cats, horses, and other animals. The objectives of this review are to demonstrate the key histopathologic and clinical diagnostic features of the various allergy-mediated reaction patterns, and to provide diagnosticians with a practical guide for clinicopathological correlations. Current concepts in the pathophysiology of immediate hypersensitivity reactions, with a focus on atopic dermatitis, are discussed. Points of potential histopathologic overlap between the "classic" allergic reaction pattern and less common inflammatory, predominately eosinophilic, conditions that may mimic this pattern will be discussed with the goal of highlighting the critical need for collaboration between pathologists and clinicians in furthering patient care.

Alternative clinical approaches to the treatment of pruritus related with canine atopic dermatitis

Canine atopic dermatitis (CAD) is a genetically inheritable, inflammatory and pruritic skin disease with characteristic clinical features, most commonly associated with IgE antibodies to environmental allergens. Itching is the most prominent clinical finding. Depending on the allergens involved, seasonal or non-seasonal pruritus may occur. &#x0D; In the first active phase of pruritus treatment, which consists of two stages, acute exacerbations should be controlled by drugs with active ingredients such as corticosteroids, oclacitinib, lokivetmab, etc. In the proactive pruritus treatment, it is aimed to prevent exacerbations and prolong the pruritus-free period with maintenance treatment. For this purpose, in addition to active phase of the therapy, different treatment options such as cyclosporine, tacrolimus, antihistamines, essential fatty acids, Palmitoylethanolamide (PEA), topical drugs and shampoos can be used to repair the skin barrier.&#x0D; Due to the side effects and costs of the drugs used in the treatment of pruritus in atopic dermatitis, researches on alternative treatment methods are still continuing. Applications such as mesenchymal stem cell therapy, recombinant canine gamma-interferon, luteolin, vitamin D, vitamin E, lactoferricin/verbascoside, mastinib, cannabidiol (CBD), probiotics and vaccination against IL-31 are the alternative treatment options for atopic dermatitis in dogs. However, more studies are needed before their inclusion in our routine clinical practices and added to the guidelines. In this review, it is aimed to provide information about new treatments used for pruritus in CAD and to encourage their use in routine veterinary clinical practice.

Efficacy of manuka honey with conventional antifungals on Malassezia pachydermatis.

Yeast infections such as otitis externa and seborrheic dermatitis in dogs and cats are frequently associated with Malassezia pachydermatis secondary infection. It is part of the normal cutaneous microflora of most warm-blooded vertebrates, however, under certain conditions, it can become a causative agent of infection that needs to be treated pharmacologically. Azole derivatives are the drugs of the first choice. An interesting trend in developing resistance is the use of natural substances, which include manuka honey with confirmed antimicrobial properties. The main intention of this research was to evaluate the mutual effect of manuka honey in combination with four conventional azole antifungals - clotrimazole, fluconazole, itraconazole, and miconazole - on 14 Malassezia pachydermatis isolates obtained from dogs and 1 reference strain. A slightly modified M27-A3 method (CLSI 2008) and the checkerboard test (Nikolić et al. 2017) were used for this purpose. Our results show an additive effect of all 4 antifungals with manuka honey concurrent use. Based on the determined values of fractional inhibitory concentration index (FICI - 0.74±0.03 when manuka honey combined with clotrimazole, 0.96±0.08 with fluconazole, 1.0±0 with miconazole and 1.16±0.26 with itraconazole), it was found in all cases that the effect of substances used is more pronounced in mutual combination than when used separately.

Pharmacokinetics of cannabidiol following single oral and oral transmucosal administration in dogs.

In the last few years, different formulations containing cannabidiol (CBD) were tested with regard to its efficacy on chronic pain, refractory epilepsy, anxiety, aggressive behavior and atopic dermatitis in dogs. CBD is generally administered orally, but its low bioavailability, probably due to a first-pass metabolism, represents a great limitation. The aim of this study was to evaluate if CBD bioavailability increases after oral transmucosal administration (OTM) compared to oral treatment. Twelve dogs diagnosed with mild chronic pain were enrolled in the study and treated once orally or OTM (6 dogs/group) with a pure CBD in oil formulation at a dosing rate of 1 mg/kg b.w. At prefixed time points, blood samples were collected to define CBD plasma concentrations vs. time profiles, and the main pharmacokinetics parameters were obtained by non-compartmental model. CBD Cmax, Tmax, terminal half-life and AUC0 - t were 206.77 ± 167 and 200.33 ± 158.33 ng/mL, 2.17 ± 0.98 and 1.92 ± 1.11 h, 2.67 ± 0.53 and 2.62 ± 0.64 h, 647.51 ± 453.17, and 536.05 ± 370.21 h*ng/mL, following oral and OTM administration, respectively. No significant difference in pharmacokinetic parameters were observed between treatments. The OTM administration did not increase cannabidiol bioavailability compared to oral treatment. The almost perfectly superimposable mean plasma concentrations of cannabidiol following the two treatments suggests that CBD is not able to be adsorbed by the oral mucosa or that its absorption is very scarce, and that CBD is swallowed and absorbed in the gastrointestinal tract.

Clinical Management of Acral Lick Dermatitis in Dogs with Comparison of Fluoxetine and Clomipramine Treatment

Background: Acral lick dermatitis is defined as self inflicted skin disorder in dogs which induces localized alopecia and fibrotic lesion due to repetitive licking or chewing at the same ‘site most commonly near carpus or hock areas. Methods: The present study was carried out to investigate the approach to the management of various etiologies associated with ALD in dogs. A total of 30 dogs that were diagnosed with acral lick dermatitis (ALD) were rated on the day 0 of theirvisit to the hospital on the basis of three clinical scalesie; ALD severity scale, clinical global impression (CGI) and likert scale. Assessment and weekly rating of the ALD lesion was done during the entire treatment trial. Result: Dogs positive for psychogenic primary triggers were randomly divided in Group 1 (n=9; 47.36%) and Group 2 (n=10; 52.63%). Dogs in group 1 were treated with fluoxetine and dogs in group 2 were treated with clomipramine. Whereas dogs diagnosed with organic triggers were treated empirically. Dogs treated under group 1 exhibited significant difference (p less than 0.05) in the licking and ALD score values at the end of the trial, however, CGI score values were found to be non significant (p greater than 0.05) with mean recovery in 24±2 days and recurrence rate of 44.44% after mean 105±47 days of their treatment completion. 33.33% dogs were also reported with adverse effects of drug as drowsiness in group 1. Dogs treated under group 2 exhibited significant difference (p less than 0.05) in pre and post treatment values of all 3 scores (licking score, ALD score and CGI score) at the end of the trial with mean recovery in 41±5 days and 55.55% cases were reported with signs of reoccurrence after mean 37±21 days of their treatment completion. Total 2(20%) dogs out of ten were presented with adverse effects; 1(10%) with loss of appetite and 1(10%) was reported with vomiting. Both clomipramine and fluoxetine are effective in treating psychogenic triggers of ALD. However, fluoxetine helps in early recovery with lesser recurrence rates whereas clomipramine having better recovery rate with fewer side effects.

Characterization of the oral and faecal microbiota associated with atopic dermatitis in dogs selected from a purebred Shiba Inu colony.

Atopic dermatitis (AD) is a chronic and relapsing multifactorial inflammatory skin disease that also affects dogs. The oral and gut microbiota are associated with many disorders, including allergy. Few studies have addressed the oral and gut microbiota in dogs, although the skin microbiota has been studied relatively well in these animals. Here, we studied the AD-associated oral and gut microbiota in 16 healthy and 9 AD dogs from a purebred Shiba Inu colony. We found that the diversity of the oral microbiota was significantly different among the dogs, whereas no significant difference was observed in the gut microbiota. Moreover, a differential abundance analysis detected the Family_XIII_AD3011_group (Anaerovoracaceae) in the gut microbiota of AD dogs; however, no bacterial taxa were detected in the oral microbiota. Third, the comparison of the microbial co-occurrence patterns between AD and healthy dogs identified differential networks in which the bacteria in the oral microbiota that were most strongly associated with AD were related to human periodontitis, whereas those in the gut microbiota were related to dysbiosis and gut inflammation. These results suggest that AD can alter the oral and gut microbiota in dogs.

Medium-chain fatty acid esters are effective even in azole-resistant Malassezia pachydermatis.

Malassezia (M.) pachydermatis as a frequent reason for dermatological consultation in dogs and cats was recently shown to be lipid-dependent, too. Lipolytic activity is a prerequisite for activating antimicrobial effectivity of fatty acid esters. It was therefore of interest whether it is possible to induce this mechanism in M. pachydermatis and to identify possible differences between minimal and strong lipid-dependent strains. In an agar dilution test, the minimal inhibitory concentrations of six fatty acid esters were determined for seventeen M. pachydermatis strains. GC analysis of parent compounds and liberated fatty acids was used to quantify ester cleavage. Hydrolysis was observed in all test strains in a homogenous manner but was dependent on the chemical structure. Lowest MICs (500 ppm after 14 days of incubation) were obtained applying glyceryl monocaprylate and 3-hydroxylpropyl caprylate, while the corresponding esters of undecylenic acid showed nearly twice the value. As shown by GC analysis with the reference strains CBS 1879 and CBS 1892 and 3-hydroxypropyl caprylate, hydrolysis and caprylic acid formation starts immediately and was dependent on yeast density. Furthermore, nine azole-resistant strains isolated from dogs with treatment failures showed MIC values comparable to the other strains and no resistance to monohydric fatty acid esters. Medium-chain fatty acid esters may represent a new therapeutic option for veterinary use even in azole-resistant strains. The in vivo verification in M. pachydermatis-associated dermatitis in dogs and cats will be the next step for the successful development of new therapeutics.

The efficacy of a novel topical spray composed of sodium benzoate, alcohol and botanical oils for the treatment of Malassezia dermatitis in dogs - a split body, randomised, blinded study.

Treatment of Malassezia pachydermatis dermatitis can be performed by systemic or topical route. As M.pachydermatis is located on the stratum corneum, topical therapy alone may be sufficient to resolve the infection. Owing to systemic antifungal resistance and adverse effects, topical treatment alone may improve treatment outcome. To evaluate the efficacy of a topical spray composed of sodium benzoate, alcohol and botanical oils, compared to a shampoo containing 2% chlorhexidine gluconate and 2% miconazole nitrate for the treatment of Malassezia pachydermaitis dermatitis in dogs. Sixteen client owned dogs diagnosed with symmetrical interdigital lesions as a result of secondary Malassezia dermatitis. The study design was prospective, randomised and single-blinded, using a split body protocol. Malassezia yeasts were determined by cytology at the inclusion day (day0) and after treatment (day14). All dogs were treated during 14 days with both shampoo at one paw and spray on the other paw. At day 14 a reduction of Malassezia dermatitis was shown at both paws. No statistical difference was demonstrated between treatment with shampoo or spray. We could not show a difference in efficacy between application of the test spray once daily and the topical use of 2%miconazole/2%chlorhexidine shampoo every other day. No adverse effects were reported.

Study of the variation of the Malassezia load in the interdigital fold of dogs with pododermatitis

The yeast Malassezia pachydermatis is a common inhabitant of the skin and mucosae of dogs. However, under certain circumstances this yeast can overgrow and act as an opportunistic pathogen causing otitis and dermatitis in dogs. Canine pododermatitis is a common disorder in dogs in which M. pachydermatis acts as an opportunistic pathogen. In the present study, the presence of Malassezia yeasts was assessed and quantified in samples collected from the interdigital space of dogs with pododermatitis before and after treatment, and from healthy dogs. The samples were subjected to two different cytological examinations, culture on Sabouraud glucose agar and modified Dixon’s agar and a quantitative PCR targeting the internal transcribed spacer (ITS) genomic region. A selection of samples was analyzed by next generation sequencing (NGS) using the D1D2 domain of the large subunit of the ribosomal DNA as target. The pododermatitis samples before treatment showed higher cell counts, colony-forming units and ITS copies than the rest of samples. The NGS analysis revealed that Ascomycota was the main phylum in the healthy and post-treatment samples. However, Basidiomycota and M. pachydermatis was more abundant in the pododermatitis samples before treatment. These results support M. pachydermatis as an opportunistic agent in canine pododermatitis by a variety of methods, and demonstrate the correlation between cytologic and molecular methods for quantification.

Dietary Intervention Alleviates Signs of Atopic Dermatitis in Dogs by Improving Gut, Skin and Systemic Immunity

ObjectivesAtopic dermatitis (AD) is a common skin disorder in dogs. We hypothesize that dietary intervention alleviates AD by improving gut, skin, systemic immunity and skin health. MethodsControl food (CF) and Test food (TF) were formulated to meet or exceed AAFCO nutritional recommendations. Both foods had similar macronutrient levels (fat: 16.2% ±1.2, protein: 17.2% ±0.9, carbohydrate: 52.9% ±0.9, crude fiber: 1.1% ±0.05, total dietary fiber: 5.0% ±0.1, moisture: 8.1% ±0.9 and ash: 4.2% ±0.2) except for the ratios of soluble:insoluble fiber (S/IF) and linolenic (C18:3):arachidonic fatty acids (C20:4) (C18:3/C20:4). The ratios of S/IF and C18:3/C20:4 are: in CF 0.04 and 10.1 and in TF 0.27 and 26.6 respectively. 14 Derm disorder dogs (DD, n = 14) and pair-matched 16 healthy dogs (HD, n = 16) were pre-fed a maintenance food for 28 days and then randomized into 2 groups based on their age, gender and disease condition followed by a cross-over design without a washout period and each phase was fed for 42 days. Fecal and blood samples were collected for all dogs and assessment of skin symptoms was conducted by a veterinarian for DD dogs. ResultsThere was an improvement in the response rate of reduced pruritus, erythema, alopecia, skin and ear secretion severity in DD by 53.8%, 46.1%, 7.6% and 38.4% respectively, when fed TF compared with CF. Mean level of fecal calprotectin and alpha 1-proteinase were decreased in DD and HD dogs when fed TF (11.8 ng/g & 18.0 μg/g) compared with CF (25.0 ng/g & 20.1 μg/g), with ±Sp 30.2 & 14.6, respectively. Similarly, mean level of serum IgE and cholesterol were decreased in DD and HD dogs when fed TF (48.8 μg/ml & 199.2 mg/dL) compared with CF (61.5 μg/ml & 226.5 mg/dL), with ±Sp 63.0 & 44.9, respectively. Metabolomic analyses revealed that TF decreased circulating acylcarnitines, but increased long chain PUFAs and NAD metabolic pathway intermediates compared with CF which indicating an anti-inflammatory, antioxidant and improvement in skin barrier function respectively. TF also decreased circulating short chain sphingomyelins and ceramides to improve skin lipid homeostasis. ConclusionsTF intervention alleviates AD via multifaceted approach by improving gut, skin and systemic immunity and skin health in dogs. Funding SourcesThis study was funded by Hill’s Pet Nutrition, Inc.

Speed of onset of a new chewable formulation of oclacitinib maleate (Apoquel®) in a canine model of IL-31-induced pruritus.

Oclacitinib maleate (Apoquel®, Zoetis Inc.) is commonly used around the world for the control/treatment of pruritus associated with allergic dermatitis and the control/treatment of atopic dermatitis in dogs at least 12 months of age. A new flavored chewable formulation of oclacitinib has been developed where more than 90% of doses offered to dogs were freely accepted when tested in clinical trials. The objective of this study was to determine whether the new chewable formulation of oclacitinib has a similar onset of anti-pruritic activity as the original oclacitinib film-coated tablets (FCT). Twenty-one laboratory beagle dogs were randomized to treatment and received placebo, 0.4-0.6mg/kg oclacitinib FCT or 0.4-0.6mg/kg flavored chewable oclacitinib tablet (n=7/group). Efficacy was measured by assessing reduction in pruritus 1-3h post-administration of treatments. Pruritus was induced by injecting canine IL-31, intravenously (2.5μg/kg), approximately 15 min prior to the pruritus observation window. Results from this study demonstrated both oclacitinib FCT and the flavored chewable oclacitinib tablet significantly reduced IL-31-induced pruritus within 1-3h post-dosing compared to placebo (p=.0069 and .0113, respectively), suggesting the new formulation of oclacitinib chewable tablets works as quickly to reduce pruritus in dogs as the oclacitinib FCT.

Role of IL‐5/IL‐5RA Axis in Eosinophilic Allergic Response in Canines with Dermatological Problems

The inflammatory response in canines with dermatological problems is likely mediated by multiple effector cells including lymphocytes, eosinophils, and mast cells. Several cytokines produced by Th2 lymphocytes including IL‐4 and IL‐31 are implicated in the pathogenesis of dermatological disorders and subsequent elevation of serum IgE and increased inflammation in the skin. Our study assessed the gene expression profile of inflammatory markers in blood samples collected from canines with dermatological problems to identify novel inflammatory markers that could lead to improved nutritional interventions. This study was approved by IACUC and the Animal Welfare Committee, Hills PNC. Gene expression was assessed in blood collected in PAXgene RNA tubes from canines with dermatological problems (Derm; n = 12; 4‐14yr) or controls (Con; n = 16; 4‐14yr), as diagnosed clinically by a veterinarian. Changes in a panel of 84 genes were analyzed using the RT2 ProfilerTM PCR Array for dog inflammatory cytokines and receptors. Blood was also analyzed for complete blood count (CBC) for circulating concentrations of leukocytes. There was a significant increase in the interleukin‐5 receptor alpha (IL‐5RA) level in derm dogs when compared to controls (1.71 fold, p&lt;0.05). There was also an increase in C‐C chemokine receptor 3 (CCR3), IL‐4 and IL‐5 (all &gt;1.25 fold, ns) in the derm dogs. IL‐5RA and CCR3 are receptors that are also expressed on eosinophils and IL‐4 is involved in the production of IL‐5. Given that IL‐5 plays a key role in the maturation and activation of eosinophils, and committed eosinophil precursors in the bone marrow express IL‐5RA and CCR3, our results indicate an important role of the IL‐5/IL‐5RA axis in dermatological disorders in canines. Consistent with this, there was a significant increase in circulating eosinophil levels in derm dogs (n=14; 0.35 x 103/μl) when compared to controls (0.28 x 103/μl; p&lt;0.05). Further, increased levels of IL‐4 and IL‐5 are associated with increased serum IgE and subsequent allergic response. We report increased serum IgE levels in derm dogs (147.7 ± 52.9 µg/ml; n=14) when compared with healthy dogs (72.5 ± 49.5 µg/ml). In addition, other pro‐inflammatory proteins that were increased in derm dogs include CCR10 (1.67), CCL16 (1.34), CCR8 (1.35), CXCR5 (1.34), LTA (1.37), and BMP2 (1.44). Interestingly, derm dogs showed a decreased level of NAMPT, a putative cytokine that is hypothesized to enhance the maturation of B cell precursors (‐1.37 fold decrease). Taken together, our results indicate the important role of eosinophilic allergic response in dermatological disorders in dogs. Targeting the IL‐5/IL‐5RA signaling axis may be important as part of newer therapeutic approaches, including nutritional strategies, to reduce dermatitis in dogs.