Veterinary dermatology最新文献

Background: Topical antimicrobial therapy is vital for managing pyoderma yet poor compliance can affect treatment outcomes.

Hypothesis/objective: To evaluate the antimicrobial activity of a 3% chlorhexidine/ophytrium shampoo at different contact times and the residual activity of a 3% chlorhexidine/ophytrium mousse against meticillin-susceptible and -resistant Staphylococcus pseudintermedius (MSSP and MRSP), Escherichia coli (EC), ESBL-producing E. coli (ESBL), Pseudomonas aeruginosa (PA), and Malassezia pachydermatis (MP) in vitro.

Animals: 18 privately owned dogs.

Materials and methods: Dogs were treated once with the shampoo for 3, 5 and 10 min, with hair samples taken after rinsing. The mousse was applied once. Hair samples were collected at 30 min (Day [D]0) and at D2, D4, D7 and D14 post-treatment. Hair bundles were plated on Mueller-Hinton (MH) agar plates pre-inoculated with MSSP, MRSP, EC, ESBL and PA, and on supplemented MH plates pre-inoculated with MP. Zones of inhibition (ZIs) were measured after 24 h (bacteria) and 48 h (MP) incubation.

Results: Shampoo-there were no significant differences in antimicrobial activity between the contact times for any of the isolates. Mousse-for all the isolates, there was significant growth inhibition compared to the negative controls on D0, D2 and D4.

Conclusions and clinical relevance: Hairs exposed to the shampoo and mousse inhibited growth of all the isolates in vitro. A 3 min contact time was noninferior to 10 min for the shampoo. The mousse showed residual activity for ≥ 4 days for MSSP, MRSP, EC, PA and MP.

Background: Alopecia X (AX) is common in Pomeranians, and skin histological results support diagnosis. AX dogs may have shiny or woolly coats; the woolly type is implicated as a potential risk indicator.

Objectives: To compare skin histological and trichographic results among Pomeranians with AX, and those unaffected by AX with woolly (W) and shiny (S) coat types.

Animals: Seventy-two Pomeranians: 30 AX, 22 W, 20 S.

Methods and materials: Skin biopsies were analysed histologically; hair pluckings assessed by trichography and scanning electron microscopy (SEM), all blinded. Statistics evaluated follicular group counts, follicle numbers, hair types, anagen follicles and fragility events. Hair cycle staging was analysed descriptively.

Results: AX dogs had fewer follicles per group (4.1) than W and S (both 5.1). Anagen stage dominated in S (60.2%), telogen in W (39.4%) and AX (39.8%). Kenogen and atrophic groups were more frequent in AX (4.7% and 10.0%, respectively) than W (1.4% and 3.4%) and S (2.0% and 1.5%). Hair fragility per 10 mg of hairs was highest in AX (85.3), followed by W (53.6) and S (26.3). Trichorrhexis nodosa ratios were for AX 12.39 (95% confidence interval [CI] 4.82-31.85) and W 3.60 (95% CI 1.37-9.94) compared to S. No differences in primary-to-secondary hair ratios were found between groups. SEM showed similar round hair morphology across groups.

Conclusions and clinical relevance: Histological and trichographic findings in non-alopecic Pomeranians reveal coat-type differences, which should be considered when diagnosing AX.

Background: Canine leishmaniosis (CanL) is a zoonotic disease of variable severity. The typical immune response is driven by an exaggerated humoral immune response. Protective immunity is mediated by pro-inflammatory cytokines that enhance macrophage leishmanicidal activity.

Objective: To evaluate the cutaneous and the systemic immune responses as well as the cutaneous parasitic load in affected dogs before and after 28 days of treatment with meglumine antimoniate.

Animals: Twelve dogs with CanL and skin lesions, treated with meglumine antimoniate at a target dose of 100 mg/kg subcutaneously every 24 h, were prospectively enrolled.

Methods and materials: Before and after 28 days of treatments, blood samples and skin biopsies were collected. Circulating levels of host defence peptides, leptin and cytokines were determined via enzyme-linked immunosorbent assay (ELISA). Paraffin-embedded skin biopsies were processed for routine immunofluorescence and positive cells were identified using commercially available anti-canine antibodies. Parasitic load also was determined via molecular methods. All variables were statistically analysed with the significance level set at 0.05.

Results: Among the cutaneous cell types investigated, there was a decrease in the number of T-box transcription factor TBX21 (Tbet⁺) (p = 0.016), GATA binding protein 3 (GATA3⁺) (p = 0.016), interleukin (IL)-17A⁺ (p = 0.03) cells and neutrophils (p = 0.008) after treatment, whereas there were no significant changes in forkhead box protein P3 (FoxP3⁺) regulatory T and ionised calcium-binding adaptor molecule 1 (Iba1⁺) cells. A lack of change in serum concentration of inflammatory mediators was found. Finally, cutaneous parasitic load was significantly lower after treatment (p = 0.03).

Conclusions and clinical relevance: The results of this study show that the reduction of cutaneous parasitic load after meglumine antimoniate treatment results in downregulation of innate and adaptive cutaneous inflammatory responses.

Background: Aural cholesteatoma (tympanokeratoma) is a destructive epidermoid cyst arising within the temporal bone. In veterinary medicine, it is a historically rare and challenging entity. In recent years, reports of cases in animals have increased, and there is a trend towards minimally invasive approaches that appear promising for better outcomes.

Hypothesis/objectives: Our objective was to assimilate prior and new knowledge of cholesteatoma epidemiology, aetiology and clinical management in animals. We utilised this information to propose a staging scheme and basic treatment principles for common veterinary species.

Materials and methods: Animal cases of cholesteatoma were identified using an advanced PubMed search. Annual incidence in dogs was estimated using previously published figures. Signalment data (breed, age, sex) were summarised for affected dogs and cats. Outcomes were summarised for studies with ≥ 2 cases and ≥ 3 months of follow up data. Previously unpublished cases, including a rabbit with spontaneous disease and a dog managed with radiation therapy, were featured to address literature gaps.

Results: Cholesteatoma is reported in > 200 dogs as well as cats, gerbils and rabbits. Brachycephaly and otitis externa appear predisposing in dogs. There may be an emerging association with aural polyps in dogs and cats. There is insufficient evidence to support radiation therapy as a primary treatment modality. Endoscopy-assisted nonsurgical and surgical approaches appear to have lower rates of clinical relapse than conventional surgery.

Conclusions and clinical relevance: This is the first work to propose a clinical staging scheme and best practices for treating cholesteatoma in companion animals. Future investigations are needed to validate or improve upon these recommendations.

Background: Sebaceous adenitis (SA) is a well-documented disease in poodles and Akitas. However, no comparative histopathological studies have been conducted across breeds affected with this condition.

Objectives: Herein, we describe the histopathological features of SA skin lesions in 20 Akita inu and 13 poodle dogs.

Animals: Inclusion criteria were Akita inu or poodle breeds with clinical signs consistent with SA and confirmed with histopathological lesions.

Materials and methods: Histopathological features of Akita inu and poodle dogs diagnosed with SA were reviewed and compared on archived skin biopsy specimens.

Results: The average age of dogs diagnosed with SA was 4.6 years in Akitas and 5.5 years in poodles. Sebaceous glands lacked in 15 of 20 (75%) biopsy specimens in Akitas and eight of 13 (62%) biopsy specimens in poodles. Perifollicular inflammation was generally present in both breeds, varying from mild, predominantly lymphoplasmacytic to moderate or severe pyogranulomatous inflammation. Akitas show a higher degree of perifollicular inflammation (p < 0.0001). Epidermal hyperkeratosis was observed in all cases in both breeds, yet poodles exhibited a more severe form (p = 0.0019). Follicular infundibular orthokeratosis was observed in most cases and was significantly higher in poodles (p = 0.04). Other commonly observed lesions were superficial dermatitis, perifollicular fibrosis and follicular fronds.

Conclusion and clinical relevance: Akitas exhibit more intense inflammatory changes than poodles, while poodles display more prominent hyperkeratotic changes and follicular fronds. These breed-specific features of SA warrant further investigation, as they may offer valuable insights into the pathogenesis of the disease.

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.