Veterinary dermatology最新文献

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: Ichthyosis fetalis (IF), also known as harlequin ichthyosis, is a rare and often fatal autosomal recessive congenital skin disorder. It is characterized by thickened, hard skin plaques and deep skin fissures that limit mobility and cause malformations of the eyes, lips and ears. Affected individuals are highly susceptible to life-threatening infections due to the disruption of the skin's protective barrier. To date, IF and its genetic basis have not been described in domestic cats.

Objectives: To characterize the gross clinical, histopathological and genetic features of IF in two stray, random-bred domestic short-hair (DSH) littermates.

Animals: Two deceased female neonatal DSH kittens, both exhibiting sparse hair and deep fissures exposing the underlying dermis. One unrelated neonatal kitten with normal skin and hair was included as a control for comparison, along with 140 feline population samples from unrelated domestic cats of various breeds.

Materials and methods: Gross clinical examination, histopathological analysis, whole-genome sequencing and population genotyping were performed.

Results: Gross clinical and histopathological evaluations confirmed a diagnosis of IF in both affected kittens. Genetic analysis identified a homozygous one base pair deletion in ABCA12, resulting in a frameshift and predicted loss of function of the encoded protein. Genotyping of 140 unrelated cats revealed that all were homozygous for the wild-type allele.

Conclusions and clinical relevance: Variants in ABCA12 have been implicated previously in IF in humans, cattle and mice. This study provides the first description of IF in domestic cats and identifies a pathogenic ABCA12 frameshift variant as the likely genetic cause.

Background: Canine atopic dermatitis (cAD) is a multifactorial, inherited skin disease, estimated to affect ≤ 15% of dogs. Studies of skin messenger mRNA in cAD currently use invasive methods, including blood sampling and biopsy collection, whilst advances in human atopic dermatitis study methodology have demonstrated reliable use of minimally invasive skin sampling techniques for similar objectives.

Objectives: To validate the use of the minimally invasive D-Squame (tape stripping; TS) method for skin mRNA analysis in dogs, and to investigate the association of highly dysregulated mRNAs with clinical response in a canine model of cAD.

Animals: Eight healthy beagles.

Materials and methods: Dogs were epicutaneously sensitised twice weekly for 7 weeks (49 days) using house dust mites (HDM; Dermatophagoides farinae). The clinical response of individual dogs to sensitisation was categorised as low, average, or high. On Day 49, D-Squame TS samples were obtained from sensitised and nonsensitised sites from each dog, and transcriptomic analyses were performed. RNA-Seq data analyses were performed using R and Bioconductor with default parameters.

Results: Comparing sensitised and control sites, 210 of 12,545 expressed genes were most differentially expressed (fold-change ≥ 2, p ≤ 0.05). CD2, CD3D/E, CD209 (T cell), IL13, TNFRSF4, CCL17 (T helper 2 cell [Th2]), FCER1A and CD80 (dendritic cells) were among the top 50 most dysregulated genes significantly correlating with sensitisation. Dysregulation of several key mRNAs, including those involved in the Th2 pathway, correlated with clinical response.

Conclusions and clinical relevance: This proof-of-concept study using a minimally invasive method to investigate skin mRNA in cAD lesions enables ethical research of immune biomarkers involved in cAD.

Background: Zinc-responsive dermatosis, characterised by parakeratotic hyperkeratosis, is most commonly reported in Arctic breeds and, more recently, suspected in Boston terriers.

Objectives: To describe the clinical and histological features of pinnal parakeratotic hyperkeratosis in French bulldogs, evaluate the response to zinc supplementation, and compare tissue zinc concentrations between affected and unaffected dogs.

Materials and methods: Sixteen French bulldogs with histologically confirmed parakeratotic hyperkeratosis were identified retrospectively across the United States. Follow-up information was obtained from medical records and owner email surveys. Tissue zinc concentrations were measured by inductively coupled plasma mass spectrometry in skin biopsy samples from affected and control French bulldogs.

Results: All 16 dogs had bilateral pinnal hyperkeratosis; six also had lesions on the nasal bridge, scrotum or tail. Of 12 dogs that received oral zinc supplementation, eight (67%) improved or achieved complete resolution, including four that responded to zinc supplementation alone. Relapse occurred in four dogs following discontinuation of supplementation, with improvement in three upon reintroduction. Tissue zinc concentrations did not differ significantly between affected and control biopsy samples.

Conclusions and clinical relevance: French bulldogs may be predisposed to pinnal parakeratotic hyperkeratosis suggestive of zinc-responsive dermatosis. Zinc methionine supplementation at approximately 2 mg/kg/day was associated with clinical improvement in most cases. Prospective studies are warranted to clarify pathogenesis, compare zinc formulations, and establish diagnostic and therapeutic guidelines.

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: Gabapentin reportedly decreases central sensitisation, a disorder associated with chronic pruritus in humans, although this is not well documented in cats. Its combined use with the standard antipruritic therapy for feline atopic skin syndrome (FASS) is not yet described.

Objectives: To evaluate the impact of prednisolone, ciclosporin or placebo, with or without gabapentin, on lesional scores and actimetry in FASS cats.

Animals: Twenty-six cats from a laboratory colony with naturally acquired FASS.

Methods and materials: Following a 12-week washout period, cats were allocated to one of three groups: prednisolone (1 mg/kg, n = 9), ciclosporin (7 mg/kg, n = 8) and placebo (Avicel, n = 9). Treatments were administered orally, once daily for 5 weeks (Week [W]0 to W4), then combined with gabapentin (10-15 mg/kg) for another 3 weeks. The Feline Dermatitis Extent and Severity Index (FeDESI) was assessed at baseline and W2, W4 and W7. Actimetry was recorded and analysed over weekend (WE) time points. A repeated-measures generalised mixed model was applied using the zero-inflated negative binomial (FeDESI) or log-normal (actimetry) distribution (α = 0.05).

Results: Prednisolone alone significantly improved FeDESI (p = 0.008), while ciclosporin required the addition of gabapentin to achieve a significant effect (p < 0.034). Gabapentin decreased FeDESI scores in all groups (p < 0.001) and demonstrated the highest incidence rate ratio (2.59) compared to placebo. Improvements in FeDESI were associated with significant (corresponding in intensity) decreases in motor activity.

Conclusions and clinical relevance: Gabapentin, particularly when combined with prednisolone or ciclosporin, may reduce lesional score and actimetry-assessed itch in FASS cats, suggesting a potential central sensitisation in some cats.

Background: Administration of interleukin (IL)-31 to healthy dogs has been used in preclinical drug testing to evaluate the antipruritic effect of novel medications through a "preventative" design approach (i.e., drugs are given before IL-31 administration).

Hypothesis/objectives: Develop and validate a "reactive" intradermal IL-31-induced pruritus model in healthy dogs by administering oral oclacitinib.

Animals: Eight adult, healthy research-bred beagles.

Materials and methods: A blinded, randomised, cross-over study. All dogs received either intradermal recombinant canine IL-31 with or without a single dose of oral oclacitinib given afterward; cross-over treatment was administered following a 4-week washout period.

Results: Oclacitinib reduced the total (p = 0.0252) and local (p = 0.0078) pruritic behaviour seconds after intradermal IL-31 injections. It also reduced the total seconds of scratching (p = 0.0078), chewing/biting (p = 0.0078) and head-shaking (p = 0.0255) behaviours. No significant reduction in licking was observed. Decreases in total pruritic seconds in this "reactive" model following oclacitinib administration were observed at 120-180 min (p = 0.0058), 180-240 min (p = 0.0075) and 240-300 min (p = 0.0241). Likewise, decreases in local pruritic behaviour seconds were observed at 60-120 min (p = 0.0498) and 240-300 min (p = 0.0343).

Conclusions and clinical relevance: The study established the first "reactive" canine intradermal IL-31 itch model in healthy dogs. One-time oral administration of oclacitinib significantly reduced the incidence of pruritic behaviours. Novel antipruritic medications can be assessed and compared using this "reactive" model in future preclinical trials.

This report presents the clinical features, clinicopathological changes, computed tomography images and response-to-treatment of a dog with calcium-laden subcutaneous fluid collections, resembling a rare form of calcinosis in humans termed 'milk of calcium'.

Background: Suppurative Malassezia otitis externa (SMO) is a rare, severe presentation of Malassezia otitis (MO) sparsely reported in the literature.

Hypothesis/objectives: The primary objective of this study was to describe the clinical presentation, diagnostic findings, treatment, and prognosis of SMO. A secondary objective was to speciate available SMO isolates, as this phenotype may be caused by different Malassezia species.

Animals: Nine client-owned dogs with SMO.

Materials and methods: A retrospective study of medical records from nine dogs with SMO diagnosed at an academic referral hospital from 2022 to 2024. Three SMO and 10 MO isolates from poodle-crosses were speciated with matrix-assisted laser desorption and ionisation time-of-flight mass spectrometry (MALDI-TOF MS).

Results: Young (average 1-year-old), male (67%), poodle or poodle-crosses (67%; six of nine dogs) were most often affected. Clinical presentation included unilateral otitis externa (77%; seven of nine dogs) with dark brown mucoid discharge, canal ulceration, erythema and glandular hyperplastic changes (100%). Cytological findings included yeast, neutrophils, and extracellular material suggestive of biofilm (100%). Prior otic treatment was primarily misdirected towards Pseudomonas otitis. Malassezia pachydermatis was identified in two SMO isolates and half of the MO isolates. Prednisone (0.5-1 mg/kg/day) per os daily tapered over 1 month plus daily otic orbifloxacin, mometasone furoate monohydrate and posaconazole (Posatex; Merck Animal Health) achieved complete resolution in 83% of affected ears without an anaesthetised otic lavage. At the time of writing, there was no known recurrence of any case within at least 6 months of treatment.

Conclusions and clinical relevance: SMO is a phenotypically severe presentation of MO clinically mimicking suppurative bacterial otitis. Young, male poodle-crosses are commonly affected. Ear canal hair plucking is likely to incite severe primary inflammation before SMO development.

Background: Amphibian skin has unique structural properties and physiological functions that make it vulnerable to environmental influences and trauma. Based on a comprehensive literature search, no large-scale study has assessed the most common causes of dermatopathies or diagnostics clinically employed in these taxa.

Hypothesis/objectives: This study aimed to evaluate aetiologies of dermatological disease, diagnostic methods, treatments and incidence of antemortem versus postmortem diagnosis of dermatological disease in amphibians under human care.

Animals/materials and methods: This descriptive retrospective study reviewed the medical records of 223 amphibians with dermatological disease evaluated at five institutions between 1 January 1986 and 1 January 2024.

Results: The most common aetiologies of dermatological disease were infectious (47.1%; 105 of 223), undefined (21.5%; 48 of 223) and inflammatory (20.6%; 46 of 223). Diagnosis of bacterial skin disease or chytridiomycosis was most often made based on histological results. Antemortem diagnostic testing was performed in 22.9% (51 of 223) of amphibians. A diagnosis was determined antemortem in 31.4% (70 of 223) of cases, and postmortem in 68.7% (153 of 223) of cases.

Conclusions and clinical relevance: Although dermatopathies are common in amphibians under human care, an antemortem diagnostic approach was uncommon, representing areas for improvement in the medical management of this taxon.