Veterinary dermatology最新文献

Background: Antimicrobial stewardship has become vital given the progressive emergence of multidrug-resistant bacteria, and novel approaches to the treatment of bacterial infections are needed. Recently, reported synergistic effects of antibacterial drugs and bacteriophage therapy have revealed promising applications for the management of meticillin-resistant staphylococcal infections.

Objectives: The objective of this study was to investigate the response of meticillin-resistant Staphylococcus pseudintermedius (MRSP) to treatment with a newly isolated, lytic MRSP-specific bacteriophage. Furthermore, a postulated synergism between phage and fusidic acid was examined in a canine ex vivo dermis model.

Material and methods: Skin was harvested from the lateral thorax of a euthanised dog, clipped, the subcutis removed, and epidermis cleaved via a modified salt-split technique. The ex vivo dermis model established in Franz diffusion cells was inoculated with 1 × 10⁷ colony-forming units (cfu) of a clinical MRSP strain for 16 h. Then, experimental groups were treated with phage vB_SpsS_LmqsKl44-4 at a concentration of 2 × 10⁶ plaque-forming units and fusidic acid 0.4 mg alone or in combination for an additional 8 h.

Results: Histopathological results showed that colonies of MRSP reached the superficial dermis and entered hair follicles. Co-treatment with fusidic acid and phage significantly reduced the amount of MRSP after 8 h.

Conclusions and clinical relevance: In conclusion, topical co-treatment with fusidic acid and a phage could be a promising approach to the treatment of canine MRSP pyoderma.

Background: Meticillin-resistant Staphylococcus pseudintermedius (MRSP) is often resistant to multiple antibiotics. Rifampicin is effective against most MRSP isolates, yet the potential for the development of rapid resistance raises questions regarding its suitability as an antibiotic monotherapy for MRSP pyoderma.

Objectives: To describe the: (i) clinical outcome of rifampicin antibiotic monotherapy in MRSP pyoderma; (ii) frequency of adverse effects; and (iii) development of rifampicin resistance among dogs considered nonresponders to therapy.

Materials and methods: A retrospective study of medical records from 1/1/2013 to 1/12/2022 of client-owned dogs with MRSP pyoderma treated with oral rifampicin as a systemic antibiotic monotherapy for 21 days.

Results: 104 dogs were included; 77 cases of superficial pyoderma (74%) and 27 cases of deep pyoderma (26%). The mean daily rifampicin dose was 6 mg/kg. Rifampicin was clinically effective in 86 cases (82.7%). Eleven of 18 nonresponding dogs demonstrated rapidly acquired rifampicin resistance (10.6%). Eighty-two (78.8%), 17 (16.3%), two (1.9%) and three (2.9%) dogs experienced zero, mild, moderate and severe adverse effects, respectively.

Conclusions and clinical relevance: Rifampicin at 6 mg/kg is an effective and mostly well-tolerated monotherapy for treating MRSP pyoderma. However, in this study, it was associated with rapid development of resistance in ≥ 10% of treated dogs. Inadequate clinical response occurred without demonstrable resistance in 6.7% of cases. Concurrent use of ciclosporin or fluconazole with rifampicin increased the odds of severe adverse reactions.

Background: Canine atopic dermatitis (cAD) is a common, chronic skin condition characterised by epidermal barrier dysfunction, immune dysregulation and cutaneous dysbiosis. While 'emollient plus' formulations are widely used in human atopic dermatitis (hAD), their role in cAD remains underexplored.

Hypothesis/objectives: To evaluate the clinical efficacy and owner-perceived value of a novel emollient plus formulation as a co-adjuvant treatment for cAD.

Animals: Twenty-one client-owned dogs with controlled, nonseasonal cAD completed the study.

Materials and methods: A proof-of-concept, bench-to-bedside study was conducted over 30 days. Dogs received a once-daily application of a novel emollient plus formulation developed in-house. Clinical outcomes were assessed using pruritus Visual Analog Scale (pVAS)10 and Canine Atopic Dermatitis Extent and Severity Index (CADESI)-04 scores, alongside skin barrier function parameters (trans epidermal water loss [TEWL] and pH) at the pinnae and inguinal areas. Owners evaluated therapeutic efficacy via the Owner Global Assessment of Treatment Efficacy (OGATE) questionnaire and sensorial acceptability through a survey.

Results: Significant reductions were observed in pVAS10 (4.25 ± 1.85 to 3.38 ± 1.79; p = 0.016) and CADESI-04 (24.62 ± 18.48 to 13.43 ± 7.44; p = 0.02) scores. TEWL (18.63 ± 17.33 to 9.56 ± 10.75; p = 0.049) and pH (6.07 ± 0.97 to 5.41 ± 0.71; p = 0.01) only had significant reductions at the pinnae. Owner satisfaction was exceptionally high, with 90.47% rating treatment efficacy as 'good to excellent'. The sensorial properties of the formulation also received consistently positive ratings.

Conclusions and clinical relevance: This cAD-targeted emollient product demonstrated promising efficacy in reducing pruritus and skin lesions while possibly improving skin barrier function. Its favourable safety profile and high owner satisfaction suggest strong potential for routine clinical use in the management of cAD. Further controlled studies are warranted to confirm efficacy and optimised treatment protocols.

Background: Tympanic membrane epithelial migration (TMEM) protects the external ear canal from infections and aids in the removal of keratin. Epidermal growth factor (EGF) accelerates tissue regeneration by stimulating cell proliferation and migration.

Hypothesis/objectives: Topical application of EGF will accelerate the canine TMEM rate.

Animals: Three male beagle dogs.

Materials and methods: Six TMs were divided into control and experimental phases. The experimental phase was assessed 2 weeks after the control phase and involved weekly EGF applications (0.5 mg/mL; 25 μg in 50 μL of phosphate-buffered saline), while the control phase involved no treatment. TMEM was assessed by applying ink spots to the TM and tracking migration on Day (D)0, D7, D14 and D21. A paired Student's t-test was used to compare the daily TMEM rates between phases.

Results: The EGF-treated phase had a significantly higher mean TMEM rate (235.0 ± 91.76 μm/day) than the control phase (146.83 ± 69.95 μm/day), showing a 60.1% increase (p < 0.05). The mean difference was 88.2 μm/day (95% confidence interval [CI]: 36.8-139.5). This difference was statistically significant based on both the paired t-test (p = 0.020) and Wilcoxon signed-rank test (p = 0.031). No differences were noted between the left and right ears, and no adverse effects occurred.

Conclusions and clinical relevance: These results suggest that EGF increases TMEM in dogs. These initial findings suggest potential clinical applications of EGF. Further studies are needed to validate these findings and evaluate their therapeutic potential.

Background: Canine atopic dermatitis (cAD) is a chronic condition requiring life-long management. Accurate diagnosis can be challenging, with no reliable diagnostic test.

Objectives: This study aimed to generate a simple diagnostic model for cAD.

Materials and methods: Machine learning by Random Forest was applied to metadata from a prospective dataset of clinical cases definitively diagnosed with cAD alone or another dermatosis. The dataset underwent a division of 67% for training and 33% for testing, with the model being trained via stratified K-fold cross-validation on the former portion, while performance assessment was conducted on the latter portion. Nine referral clinicians across four European countries contributed 645 cases.

Results: Modelling confirmed the value of the four tested metadata on a dog's history and reduced the initial 15 lesion locations tested to three. Metadata for the final model were: predisposed breed (any from a list of 31), predominantly indoor life, dermatitis onset age between 6 months and 3 years, dermatitis chronic, recurrent or a permanent background. Lesion locations were axilla, inguinal and other. Diagnostic prediction was 95% sensitive and 84% specific.

Conclusions and clinical relevance: This model is a relevant prototype for an app-based tool to support general practitioners in the diagnosis of cAD alongside existing tests. It has high sensitivity and specificity based on four questions and three lesion locations obtained from a standard history and clinical examination.

Background: Cytological examination of the ear canal is essential for evaluating dogs with otitis externa (OE). The conventional sampling method uses a swab. However, the cytobrush (gynaecological cervical brush), already used for cytological collection from other anatomical sites, has not been adequately investigated for this purpose in dogs with OE.

Objectives: To compare the cytobrush as a sampling tool for the ear canal of dogs with OE and compare it with the swab technique.

Animals: Thirty ears from 17 dogs with OE, presented at a veterinary teaching hospital, were included for sampling.

Materials and methods: Cytological samples were collected using both a cytobrush and a swab in random order. Two independent and blinded evaluators quantified micro-organisms (cocci, bacilli, yeasts), mononuclear cells, polymorphonuclear cells and epithelial cells. Animal discomfort during sampling was assessed using a scoring system.

Results: No significant differences were found between the methods regarding the presence of micro-organisms or inflammatory and epithelial cells (p > 0.05), indicating equivalence between techniques. The intraclass correlation coefficient (ICC > 0.9) demonstrated high reproducibility between evaluators. Although the oto-podal reflex was more frequent with the cytobrush, it did not significantly impact overall animal discomfort.

Conclusions and clinical relevance: The cytobrush is an effective, safe and well-tolerated sampling method, and may be considered a viable alternative to the swab for collecting samples from the ear canal of dogs with OE.

Background: Identification of offending foods in dogs with adverse food reactions is usually based on "deterioration" during open food challenges.

Objectives: To examine the placebo effect during double-blinded, placebo-controlled food challenges using a predefined set of criteria for relapse.

Animals: Twelve dogs with atopic dermatitis and adverse food reactions.

Materials and methods: Dogs were serially challenged with 40 g/day of eight food items (beef, chicken, codfish, corn flour, cow's milk, hen's egg, lamb, wheat), for 1 week, each mixed with their elimination diet and water. An additional two challenges were placebo (elimination diet mixed with water). Owners and investigators were blinded to the challenges and the order of the 10 challenges was randomised for each dog. Relapse was defined as moderate-to-severe owner global assessment of challenge deterioration and/or > 100% increase of Canine Atopic Dermatitis Extent and Severity Index, 4th iteration (CADESI-04) score (with the score at the end being > 9) and/or > 100% increase of pruritus using a Visual Analog Scale (with the score at the end being > 1.9/10).

Results: Most (91.7%) dogs were positive to one to six challenges with food items, yet half of them also were falsely positive in one placebo challenge. Two dogs had only one placebo challenge. The number of positive challenges to foods did not differ between dogs with positive and negative placebo challenges.

Conclusions and clinical relevance: The placebo effect during double-blinded food challenges creates doubts about the accuracy of the results of challenges with food items in this and in previous studies where open food challenges were used.

Background: Oclacitinib and lokivetmab are generally effective monotherapies for the treatment of canine allergic dermatitis yet treatment failures may occur.

Objective: To evaluate the efficacy of the combination of oclacitinib-lokivetmab therapy (COLT) in dogs that previously failed monotherapy.

Animals: Forty-four client-owned dogs diagnosed with allergic dermatitis that did not respond to both oclacitinib and lokivetmab as monotherapies were then treated with COLT.

Results: Twenty-seven of 44 (61.4%) dogs responded adequately to COLT based on a ≥ 2 cm reduction in the pruritus Visual Analog Scale (pVAS) score from baseline and client/clinician consensus on improvement. In dogs that responded, the mean pVAS for monotherapy (oclacitinib and lokivetmab group data combined) was 6.87 of 10 and fell to 2.67 of 10 after COLT (61.1% decrease; p < 0.0001). No adverse effects were noted with COLT.

Conclusions and clinical relevance: This study suggests that in dogs not adequately responsive to oclacitinib or lokivetmab monotherapy, COLT may provide superior control of pruritus.

Background: Topical corticosteroids (TCS) phobia refers to the negative feelings and beliefs related to TCS. TCS phobia may lead to a lack of adherence to therapy and treatment failure in patients diagnosed with atopic dermatitis.

Objectives: To quantify TCS phobia amongst pet owners of dogs diagnosed with canine atopic dermatitis (cAD) with the hypothesis that there is no TCS phobia.

Materials and methods: A validated topical corticosteroid phobia (TOPICOP) questionnaire adapted for veterinary use-termed Veterinary Topical Corticosteroid Phobia (VETCOP)-plus four additional questions were uploaded onto an online platform. Pet owners of dogs diagnosed with cAD from China and Singapore were recruited into the study via a QR code, and data were statistically analysed.

Results: In total, 363 respondents (276 female, 87 male) were enrolled in this study. The global median VETCOP score was 52.8%, with females exhibiting higher TCS scores compared to males, and older (> 60-year-old) pet owners expressing higher TCS scores than other age brackets. Surveyed pet owners expressed utmost concerns about their need for reassurances when TCS are prescribed and their willingness to pay for more expensive allergic medication other than glucocorticoids (topical or systemic).

Conclusions and clinical relevance: Based on the findings of this study, TCS phobia could potentially be a widespread problem in veterinary dermatology, and veterinary surgeons may be the only source of information regarding the use of TCS on pets. The failure to communicate or reassure pet owners when TCS is prescribed may lead to therapeutic failure.

Background: DNA-based vaccination rapidly induces strong cellular and humoral immune responses, which may be enhanced by inclusion of lysosomal-associated membrane protein-1 (LAMP).

Objectives: This proof-of-concept study evaluated the efficacy and safety of a Der f 2/Zen 1-LAMP-based DNA vaccine immunotherapy in client-owned dogs with nonseasonal AD sensitised to Dermatophagoides farinae (Df).

Animals: Fifteen dogs positive for Df only and 20 dogs with reactivity to additional environmental allergens received either a low (0.5 mg/0.1 mL) or high (2 mg/0.4 mL) dose of the vaccine intradermally.

Materials and methods: Four doses of vaccine were administered every 2 weeks. Pruritus, Canine Atopic Dermatitis Extent and Severity Index (CADESI)-04, average daily medication scores (AvdMS) and adverse events (AE) were recorded over 24 weeks. Owner perception of treatment efficacy (OGATE) was assessed at the end.

Results: Pruritus and CADESI-04 improved regardless of the sensitisation profile and the vaccine dose. After 24 weeks, despite a statistically insignificant reduction of AvdMS, 71%, 46% and 86% of dogs reached PVAS < 3.6, PVAS < 2 and CADESI-04 < 10, respectively. There was no statistically significant effect of AvdMS on PVAS or CADESI-04, meaning that the concurrently administered topical and/or systemic treatment(s) were unlikely to have been responsible for the observed PVAS and CADESI-04 reduction. Twenty-one owners (60%) rated the vaccine efficacy as good-to-excellent. No severe AEs were reported.

Conclusions and clinical relevance: These results of this proof-of-concept study support not only the safety of DNA vaccine immunotherapy in dogs with AD, but also its potential clinical benefits. A double-blinded, ≥ 12 month long, controlled study with more subjects should follow to further confirm the true efficacy of this vaccine.