Veterinary dermatology最新文献

Background: Targeted antimicrobial therapy for canine otitis externa (OE) represents an opportunity for antimicrobial stewardship. Fosmidomycin selectively inhibits the non-mevalonate pathway for isoprenoid biosynthesis utilised by canine-adapted, and not human-adapted, staphylococci.

Objectives: To evaluate the safety and efficacy of fosmidomycin for treatment of bacterial OE compared with enrofloxacin.

Animals: Fifteen client-owned dogs with bilateral bacterial OE were enrolled.

Materials and methods: Fosmidomycin stability in solution for 28 days was confirmed before trial commencement. A 'split body' design was used: each ear canal was randomised to receive a solution of fosmidomycin or enrofloxacin applied twice daily for 28 days, combined with a tapering anti-inflammatory course of oral prednisone. Owners and investigators were blinded to treatments. Dogs were evaluated at Day (D)0, D14 and D28 with clinical scores (0-3 otitis index score [OTIS3], ear cytological results, pain) and owner assessments (pruritus scores for each ear, quality-of-life scores and a hearing questionnaire). On D28, owners and investigators assessed global treatment efficacy for each ear.

Results: Treatment group did not significantly influence clinical scores; cytological scores, OTIS3 scores and pruritus scores significantly improved for both groups over the trial period. Treatment efficacy for both ears was assessed as good-to-excellent by owners and investigators for the majority of dogs. No safety concerns were identified.

Conclusions and clinical relevance: Fosmidomycin and enrofloxacin performed comparably for topical treatment of bacterial otitis in this study. Fosmidomycin is a promising targeted antimicrobial for canine bacterial infections while limiting selection for antimicrobial resistance in human pathogens such as Staphylococcus aureus.

Background: Erythema multiforme (EM) and similar cytotoxic dermatoses, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), represent immune-mediated conditions that have clinical, histopathological and immunohistochemical overlap with other diseases. Although reactive processes are typically associated with polyclonal expansion of lymphocyte populations, benign clonal expansion is possible in non-neoplastic conditions.

Hypothesis/objectives: The purpose of this study is to elucidate the role of clonality in differentiating cases of canine EM/SJS/TEN from cutaneous epitheliotropic lymphoma. Further aims include providing clinical correlation and response to therapy in combination with clonality. It is hypothesised that both clonal and polyclonal expansions will be observed in cases of EM/SJS/TEN.

Animals: Twelve dogs with clinical and histopathological changes supportive of EM or SJS/TEN.

Materials and methods: Clinical data, histological and immunohistochemical examination as well as clonality for T-cell receptor gamma (TRG) was performed for tissue samples in canine EM/SJS/TEN. Modified drug scoring was performed for cases with medication administration before lesion development.

Results: Twelve cases were included for retrospective review. Good response to therapy, CD3 immunoreactive T cells, and at least minor expression of Granzyme B were noted in all cases. Eleven of 12 had mild-to-moderate CD20 dermal infiltration. Polyclonal populations were noted in four cases, polyclonal with minor clones in five cases and clonality in three cases. Modified drug scoring was positive in five of six cases.

Conclusions and clinical relevance: This study describes cases of canine EM/SJS/TEN demonstrating both polyclonal and clonal T-cell expansion, further highlighting the need for pairing clinical response with histopathological results and advanced diagnostics.

Background: Dermatophytosis is an infectious skin disease caused by fungal organisms collectively known as dermatophytes. In cats, the most commonly isolated dermatophyte is Microsporum canis. Known predisposing factors include young age, long hair coat, lifestyle, warm geographical locations and Persian breed.

Hypothesis/objectives: The aim of this retrospective study was to evaluate the prevalence of dermatophytosis in cats of different breeds in a dermatological referral practice in Italy over a 9 year period, highlighting clinical and breed-related differential features.

Animals: 1457 cats of different breeds, 54 of which were affected by dermatophytosis.

Materials and methods: Cases of feline dermatophytosis diagnosed between 1 January 2016 and 31 December 2024 were searched. Cases were included based on availability of signalment, clinical presentation and confirmation of diagnosis with positive microscopic examination of hair shafts and/or Wood's lamp examination and positive fungal culture.

Results: The prevalence of feline dermatophytosis in our sample was 3.7%, with M. canis identified in all cases. Dermatophytosis was more frequently diagnosed in Persian cats (14 of 66, 21.2%) and Persian-related breeds, including British shorthair (10 of 39, 25.6%), exotic shorthair (two of 22, 9.1%) and Scottish fold (two of 20, 10%). Among Domestic short hair (DSH) cats, the prevalence was 2.1%. Young age was a predisposing factor and in pure-bred kittens contagion most likely occurred at the breeder's facility. Pruritus was reported in 63% of the cats.

Conclusions and clinical relevance: The disease was frequently diagnosed in Persian cats and Persian-related breeds. Cats aged < 1 year are predisposed. Pruritus is common, regardless of the breed.

Background: Psoriasiform lichenoid dermatosis (PLD) is a rare lesion in dogs receiving calcineurin inhibitors, associated with staphylococcal infection.

Objectives: To define the clinical features of dogs with a histopathologic diagnosis of PLD.

Results: Twenty-eight dogs were included in this retrospective study. PLD was focal (4/28), multifocal (17/28) or regional/generalised (7/28). Twenty-seven of 28 dogs received a calcineurin inhibitor with a median time to lesion onset of 6 months (1-24 months). Twenty-three of 28 dogs received ciclosporin (ciclosporin alone: 15/23; ciclosporin with ketoconazole: 7/23). Formulations included generic modified ciclosporin (12/23), brand-name modified ciclosporin (7/23), compounded modified ciclosporin (1/23) or unknown formulation (3/22). Four dogs had gingival hyperplasia or paw-pad hyperkeratosis. Four dogs received topical tacrolimus. No breed or sex predilection was found. The median age of onset was 7 years (3-12 years). In 22/28 dogs, bacteria were seen on lesional cytology, and Staphylococcus pseudintermedius was isolated with bacterial culture from nine dogs. Short-read whole genome sequencing was performed on three isolates. Most dogs received antimicrobials before (14/28) and/or after diagnosis (22/28 dogs).

Outcomes/clinical relevance: PLD occurs in adult dogs irrespective of breed with varied forms of calcineurin inhibitors. Twenty of 28 dogs achieved > 50% improvement or complete (100%) lesion resolution after topical and/or systemic antimicrobial therapy and discontinuation with or without dose reduction of the calcineurin inhibitor.

Background: The chronic and multifactorial character of canine atopic dermatitis (cAD) often leads to poor disease control and treatment dissatisfaction. Environmental factors are likely to contribute to the disease development and may play a more important role than assumed previously. This opens new research directions that require an appropriate tool to obtain useful data from large representative study populations.

Hypothesis/objectives: A tool such as a questionnaire is suitable for obtaining high-quality data to investigate the pathogenesis of cAD and monitor the disease.

Materials and methods: To assure the tool's validity and reliability, the development process of this four-language questionnaire (original language German) included two pilot tests (with owners' interviews and questionnaire evaluation sheets), test-retest assessment, content validity evaluation and a structured translation and back-translation into three languages (English, Italian and French).

Results: The development process took place between June 2024 and December 2024. The preliminary questionnaire comprised 107 questions. The pilot tests (round 1 = four participants, round 2 = two participants) resulted in a revision of 31 questions and the deletion of three. The test-retest assessment revealed an Intraclass Correlation Coefficient of 0.80. The panel of (six) experts evaluated the questionnaire with a content validity index of 0.99. The translation and back-translation process revealed that only minor adjustments were sufficient to guarantee the validity and reliability across languages.

Conclusions and clinical relevance: The comprehensive development process ensures high validity and reliability of the questionnaire, indicating that such a process can not only positively impact the quality of the developed tool, but also create a reliable basis for the generation of accurate and less biased data.

Background: The antibacterial efficacy of chlorhexidine shampoo is directly affected by formulation and bathing factors.

Hypothesis/objective: To evaluate the in vitro antibacterial efficacy of chlorhexidine-containing shampoos at various dilutions and to compare their lathering ability.

Animals: No animals were utilised in this study.

Materials and methods: Eight chlorhexidine-containing shampoos, three non-chlorhexidine shampoos, and a 2% chlorhexidine gluconate solution were tested against one American Type Culture Collection (ATCC) meticillin-sensitive Staphylococcus pseudintermedius and one institutional meticillin-resistant S. pseudintermedius isolate. The effect of formulation on minimum inhibitory concentration (MIC) was determined using a broth microdilution method. The first dilution that had no visible growth and four preceding dilutions were plated on blood agar to determine the minimum bactericidal concentration (MBC). Lathering ability and lather stability were assessed using a modified cylinder shake method. MIC and MBC were compared for the dilution ratio and chlorhexidine gluconate/digluconate concentration using a Kruskal-Wallis test with Bonferroni correction (p < 0.001).

Results: All products had a detectable MIC. Statistically significant differences between MIC and MBC were observed between shampoos that were not based on chlorhexidine concentration alone. Two non-chlorhexidine shampoos had no detectable MBC. Over time, all shampoos had a significant decrease in lather height. Lathering ability significantly differed between some shampoos.

Conclusions and clinical relevance: This preliminary study suggests that shampoo formulation and not just chlorhexidine concentration impacts efficacy. Further investigation with more robust numbers of bacterial isolates and large-scale head-to-head clinical trials is required to determine if the reported in vitro variance has clinical significance.

Background: Recurrent otitis externa (OE) episodes commonly affect dogs with canine atopic dermatitis (cAD) despite ongoing cAD treatment.

Objective: To determine if a therapeutic diet with active ingredients targeting the skin barrier and allergy pathways reduces the incidence rate of OE.

Animals, materials and methods: Thirty-four client-owned dogs with active erythroceruminous OE + cAD (not necessarily active) were randomised to test (n = 16) or control diet (n = 18), fed for up to 6 months. Dogs had to be in remission by Month (M)1 after initial OE treatment. Outcomes included incidence rate (percentage of dogs with ≥ 1 OE episode), 0-3 Otitis Index Score (OTIS-3), cAD Extent and Severity Index, 4th iteration (CADESI-04), and medication score (medication required to control OE and/or cAD) at M3 and the end-point, defined as each dog's last on-study data.

Results: The incidence rate was significantly lower in the test versus control group (25% vs. 61%, p < 0.01). OTIS-3 and CADESI-04 improved significantly between baseline and M3 in both groups (control: p = 0.003 and p < 0.001; test: each p = 0.001). Between M3 and the end-point, OTIS-3 and CADESI-04 rebounded significantly in the control (p = 0.025 and p = 0.026) and not in the test group (p = 0.139 and p = 0.909). CADESI improvement from baseline was maintained at the end-point in the test (p < 0.001) and not in the control group (p = 0.227). Medication score improved significantly throughout the diet duration in the test group (baseline to M3, M3 to end-point, and baseline to end-point) versus no improvements in the control group.

Conclusion and clinical relevance: A therapeutic diet for cAD helped to sustain improvements in aural manifestations.

Background: Microfilarial dermatitis was described once in dogs of the western United States. The organisms were not identified.

Hypothesis/objective: To identify nematodes as a cause of dermatitis and describe clinical features, treatments and therapeutic responses.

Animals: Eight client-owned dogs with suspected or definitively diagnosed microfilarial dermatitis based on appropriate clinical history and therapeutic response had skin biopsy samples collected.

Materials and methods: Retrospective review of electronic medical records taken between January 2010 and December 2022 from a multicentre dermatology speciality group in the United States for dogs, followed by PCR and genome sequencing of microfilariae from formalin-fixed tissue.

Results: Pruritus (eight of eight), plaques (five of eight) and lesions of the head (six of eight) were commonly reported. Four had microfilariae on histopathological evaluation. One sample was genetically consistent with Cercopithifilaria bainae; another was consistent with Onchocerca lupi. Two formalin-fixed paraffin-embedded samples were not available for sequencing. Dogs received oral pulse dosing of fenbendazole (Panacur; Merck Animal Health) (mean 41 mg/kg) at 10-day intervals for 4 weeks and injectable ivermectin (Agri-Mectin; AgriLabs) (mean 0.42 mg/kg) given orally once weekly for 6 weeks. Three dogs had adverse drug events. One dog had recurrent clinical signs after experiencing full resolution. Complete resolution without recurrence was reported in two of eight dogs. The times to complete resolution were 63 days (Dog 5) and 65 days (Dog 3).

Conclusions and clinical relevance: This is the first confirmed report of clinical dermatitis secondary to O. lupi microfilariae in a dog, and the second clinical description of canine C. bainae microfilarial dermatitis in the United States. Paired ivermectin and fenbendazole may be an appropriate treatment for suspected or definitively diagnosed canine microfilarial dermatitis.

Background: Short-chain fatty acids (SCFAs), including acetic, propionic and butyric acids, are key gut microbiota metabolites with anti-inflammatory properties. Lower SCFA levels have been observed in human patients with atopic dermatitis (AD) and have been shown to be able to predict disease development. Although differences in faecal SCFA concentrations have been described in other canine diseases, such studies are lacking in canine (c)AD.

Hypothesis/objectives: To measure SCFA concentrations in the faeces of cAD-diagnosed and healthy dogs to assess potential differences.

Animals: The study included 25 client-owned dogs with cAD and 27 healthy controls.

Materials and methods: Owners collected faecal samples which were frozen at -80°C for ≤ 4 months. Gas chromatography was used to analyse acetic, propionic and butyric acid concentrations.

Results: Mann-Whitney U-tests revealed significantly lower concentrations in acetic (p < 0.001), propionic (p = 0.0271) and butyric acids (p < 0.001) in the group of dogs with cAD compared with the control group.

Conclusions and clinical relevance: This is the first report on the measurement of faecal SCFAs in dogs with cAD. This pilot study highlights potential links between SCFA levels and cAD, suggesting possible future therapeutic and biomarker applications. A larger-scale study is recommended to validate these findings.

Background: Otitis externa (OE) with secondary bacterial or yeast infection is a common problem in small animal practice. Cold physical plasma (CPP) has been reported to have antimicrobial activity in vitro.

Hypothesis/objectives: This randomised, blinded, prospective study assessed the influence of additional CPP treatment on the recovery of canine OE with secondary infection.

Animals: Twenty-one dogs with bilateral clinical OE and cytological evidence of infection were included.

Materials and methods: An ear flush was performed with saline solution in all dogs. Additionally, one ear of each dog, chosen in a prospective randomised fashion, was treated with CPP for 30 s. Afterwards, both ears were treated with a depot ear medication containing betamethasone, terbinafine and florfenicol. Seven days later, the depot medication was administered again as recommended by the manufacturer. On Day (D) 0, D7 and D21, a clinical otic score and a validated semiquantitative cytological score were compared with a Friedman test and Dunn's multiple comparison test.

Results: Ears treated additionally with CPP showed lower otic scores after 21 days compared to nontreated ears, although this difference was not significant (p = 0.08). Cytological scores improved over 21 days with cocci in CPP-treated (p = 0.003) and nontreated ears (p = 0.02). With yeast, there was significant improvement in CPP-treated (p = 0.0002) ears in contrast to nontreated ears. With rods, the improvement was not statistically significant in either group.

Conclusions and clinical relevance: CPP treatment seems to be a promising option as an additional treatment after ear flushing.