Veterinary dermatology最新文献

Background: Canine cutaneous epitheliotropic lymphoma (CEL) is a rare neoplastic disease with poor prognosis. Oclacitinib, a Janus kinase inhibitor primarily used to treat allergic and atopic dermatitis in dogs, may also cause other skin diseases.

Objectives: This study aimed to evaluate the efficacy of oclacitinib in the treatment of canine cutaneous lymphoma.

Animals: Eight client-owned dogs with CEL were included in the study.

Materials and methods: The dogs were administered oclacitinib. This study examined the immunological characteristics, time to treatment initiation, dosage, cutaneous lesions and pruritus, adverse events, survival time and prior oclacitinib use.

Results: Only one of the eight dogs (12.5%) showed symptomatic improvement after oclacitinib treatment, with no clinical improvement observed in the other cases. Improvement in pruritus was noted in only one dog. Adverse events included mild leucopenia in one dog, which did not significantly affect prognosis. The median survival time after diagnosis was 228.5 days.

Conclusions and clinical relevance: These results suggest that oral oclacitinib has limited efficacy in the treatment of canine CEL. Larger prospective studies are recommended to further investigate the optimal dose, treatment duration and potential combination therapies involving oclacitinib.

Background: Canine superficial bacterial folliculitis (SBF) is a common recurrent condition with a growing requirement for culture and susceptibility as a consequence of increased antimicrobial resistance and antimicrobial stewardship. Different opinions persist about the ideal technique for culture sample acquisition, which varies with lesion characteristics.

Objective: To determine if a difference exists in the recovered quantity of bacteria acquired when sampling nonexudative clinical lesions of SBF (crusts and epidermal collarettes) between a dry culture swab and a saline-moistened culture swab.

Animals: Nine dogs with crusts or epidermal collarettes and cytological findings consistent with SBF were recruited.

Materials and methods: Each clinical lesion was divided into two halves. One half of the lesion was sampled with a dry cotton sterile swab, while the other half was sampled with a sterile swab saturated with sterile saline. Each lesion was sampled with the culture swab by rolling it over the corresponding half four times. Aerobic quantitative cultures were then performed to determine the number of Staphylococcus-type colonies present.

Results: A total of 19 lesions (13 crusts and six epidermal collarettes) were evaluated. Dry culture swab identified a mean staphylococcal bacterial count of 3.83 Log₁₀ colony-forming units (cfu)/mL (standard deviation [SD] = 0.70). The saline-soaked culture swab revealed a median bacterial count of 4.41 Log₁₀ cfu/mL (SD = 0.77). There was a statistically significant difference between the sample collection methods (p = 0.002).

Conclusions and clinical relevance: Sterile saline-soaked swabs are more likely than dry swabs to result in increased recovery of bacteria from nonexudative lesions.

A 10-year-old fennec fox (Vulpes zerda) was presented for multifocal regions of chronic alopecia and crusting. Cutaneous lymphocytosis was diagnosed through histopathological examination and immunohistochemical investigation. Clonal rearrangement of the T-cell receptor gamma locus supports that lymphocytosis in this case was an indolent lymphoma.

Background: Diff-Quik (DQ) staining is widely used in clinical practice for its ease of use and rapid results. However, its potential contamination remains a concern.

Hypothesis/objectives: This study aimed to investigate DQ solution contamination in veterinary hospitals and identify factors affecting it through a questionnaire on stain usage practices.

Materials and methods: A survey was conducted to assess the use of DQ staining in local animal clinics. Samples of DQ solution II collected from each hospital participating in the survey were cultured and analysed microscopically for contamination.

Results: A total of 67 DQ stain samples were collected from veterinary hospitals, of which 10 (14.92%) were found to be contaminated with pathogens. Bacterial cultures were positive in six of the samples (8.95%); four were contaminated with Staphylococcus pseudintermedius, one with Stenotrophomonas maltophilia and one with Bacillus haynesii. Malassezia pachydermatis was found in the remaining contaminated samples (n = 4, 5.97%). Statistical analysis revealed that the significant factors associated with DQ stain contamination were the use of a dropper, direct immersion of slides in the dye, average weekly usage and periodic replacement of the solution (p < 0.05).

Conclusions and clinical relevance: This study confirms DQ solution contamination in general veterinary practice. To minimise contamination risk, using a dropper for stain application instead of direct specimen immersion in the stain is recommended. Furthermore, in hospitals where DQ solutions are frequently employed, the stain should be periodically replaced or examined under a microscope.

Background: Recurrent urticaria is common in horses. The pathophysiology is poorly understood and treatment options are limited. Often, only glucocorticoids are effective for controlling clinical signs, albeit with potential adverse effects. Studies investigating new treatments need a validated objective scoring system for the grading of skin lesions to assess response.

Hypothesis/objectives: The aims were to investigate inter- and intraobserver reliability of the Equine Urticaria Activity Score (EqUAS) for the grading of skin lesions in horses with recurrent urticaria, and to examine agreement between experienced and inexperienced observers.

Animals: Forty privately owned horses enrolled in a therapeutic clinical trial.

Materials and methods: Ten standardised photographs of both sides of the body of each horse were used to create 40 individual datasets. Five masked observers graded the photographs according to the EqUAS for calculation of interobserver reliability. Intraobserver reliability was calculated from two observers each grading the photographs twice. Scores were evaluated for reliability with Pearson's correlation (r) and for agreement with the intraclass correlation coefficient (ICC).

Results: Interobserver reliability was excellent with r = 0.9036-0.9600 (p < 0.0001). Intraobserver reliability and agreement also were excellent with r = 0.98 for each observer (p < 0.0001) and ICC = 0.945. Correlation and agreement between experienced and inexperienced observers were excellent (r = 0.9615 [p < 0.0001] and ICC = 0.941).

Conclusions and clinical relevance: The EqUAS showed excellent intra- and interobserver reliability for the evaluation of skin lesions of horses with chronic recurrent urticaria. It can be a useful tool in clinical studies.

Erythema annulare centrifugum (EAC) is an inflammatory skin condition characterised in humans by distinctive annular erythematous lesions. Three hairless dogs were examined with clinical and histological features suggestive of EAC. Oral or topical glucocorticoid administration led to complete clinical resolution.

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: Apoptotic keratinocytes have been described with canine epitheliotropic cutaneous T-cell lymphoma (eCTCL) without further detailed characterisation of this feature.

Hypothesis/objectives: This study aims to characterise confirmed eCTCL cases enriched with apoptotic keratinocytes as a novel cytotoxic variant of canine eCTCL.

Animals: Canine eCTCL cases from a veterinary pathology diagnostic laboratory database were searched from 2018 to 2024.

Materials and methods: Haematoxylin and eosin-stained slides were examined for evidence of lymphocytes, apoptotic keratinocytes with lymphocytic satellitosis, and epitheliotropism in the lower half of the epidermis and adnexal structures by a board-certified veterinary pathologist. Immunohistochemical (IHC) staining for CD3 and CD20 was performed in addition to clinical follow-up with response to treatment, and PCR for Antigen Receptor Rearrangement (PARR) assay (T and B cell).

Results: Six cases with representative features were identified. Various breeds were affected with a median age of 10 years at presentation. Skin lesions included generalised crusting, scaling, erythema and erosions/ulcerations; mucocutaneous junctions were involved in three of six dogs. Histopathological results confirmed an interface cytotoxic pattern eCTCL in all cases, marked by lymphocytic epitheliotropism and apoptotic keratinocytes. IHC staining demonstrated > 90% strong CD3⁺ T-cell immunoreactivity in the epidermis and follicular epithelium in all cases. All six confirmed cases showed clonality for the T-cell receptor gene using PARR analysis.

Conclusions and clinical relevance: This cytotoxic variant of canine eCTCL clinically and histologically can resemble other cutaneous diseases with cytotoxic dermatitis (e.g., hyperkeratotic erythema multiforme). IHC and clonality testing and monitoring response to treatment may be necessary for definitive diagnosis.