Veterinary dermatology最新文献

Background: Feline Bowenoid in situ carcinoma (BISC) is frequently associated with Felis catus papillomavirus-2 (FcaPV-2). Although surgical excision of BISC is expected to be curative, recurrent lesions are reported and it is not known whether it is a consequence of incomplete surgery or residual viral load.

Objectives: To combine colorimetric in situ hybridisation (CISH) and quantitative (q)PCR for the detection of viral DNA, and to correlate the clinical outcome of cats with BISC in which FcaPV-2 DNA is detected at surgical margins.

Animals: Twenty-seven cats with a histopathological diagnosis of BISC.

Materials and methods: Sections including core and margins of the lesions were used for histopathological evaluation, qPCR and CISH. After surgical removal of the lesion, clinical follow-up data were recorded for 6 months.

Results: Six of 12 cases in which all four histological margins were evaluable were used to correlate the infection status at the margins with the follow-up data. Four showed margin positivity, of which half relapsed as expected and half cured; two cases were negative, of which one cured as expected while the other relapsed. Fifteen cases where only three, two or one of the histological margins were evaluable, were considered to adequately correlate the status of infection with the follow-up data if CISH was positive. Follow-up data were available for three with positive margins: one relapsed while the other two were cured.

Conclusions and clinical relevance: Wide clinical surgical margins are always recommended for neoplastic conditions, yet there was no evidence that CISH margin examination would be beneficial in predicting recurrence in this viral-induced lesion.

Background: Bacterial identification and antimicrobial susceptibility testing is an important step in timely therapeutic decisions for canine superficial bacterial folliculitis (SBF), commonly caused by Staphylococcus pseudintermedius. Next-generation sequencing (NGS) offers the appeal of potentially expedited results with complete detection of bacterial organisms and associated resistance genes compared to culture. Limited studies exist comparing the two methodologies for clinical samples.

Hypothesis/objectives: To compare and contrast genotypic and phenotypic methods for bacterial identification and antimicrobial susceptibility from cases of canine SBF.

Animals: Twenty-four client-owned dogs with lesions consistent with SBF were enrolled.

Materials and methods: A sterile culturette swab was used to sample dogs with SBF lesions. The swab was rinsed in 0.9 mL of sterile phosphate-buffered saline and vortexed to create a homogenous solution. Two swabs for NGS laboratories (Labs) and one swab for culture (Culture Lab) were randomly sampled from this solution and submitted for bacterial identification and antimicrobial susceptibility.

Results: No statistical difference regarding turnaround time for NGS Labs compared to Culture Lab was found. NGS Lab 1 identified more organisms than NGS Lab 2 and Culture Lab, which were both statistically significant. There was no statistical difference in detection frequency for Staphylococcus spp. among all laboratories. There was poor agreement for the presence of meticillin resistance and most antimicrobials among all laboratories.

Conclusions and clinical relevance: Utilisation of NGS as a replacement for traditional culture when sampling canine SBF lesions is not supported at this time.

Background: Few studies have investigated optimal storage conditions or expiration dates for sublingual immunotherapy (SLIT) formulations prepared from glycerinated allergen extracts.

Hypothesis/objectives: The objective of this study was to compare concentrations of short ragweed major allergen (Amb a 1) and total protein in SLIT formulations stored at two different temperatures. It was hypothesised that protein concentrations would show greater decline over time in a formulation stored at room temperature (RT) than in one stored under refrigeration.

Materials and methods: Two SLIT samples containing equal volumes of 20,000 PNU Amb a 1 extract were prepared and stored at refrigerated cold (CT) (2-8°C) or RT (20-24°C) for 140 days. Changes in total protein and major allergen concentration and composition were measured by Bradford assay, two-site enzyme-linked immunosorbent assay and SDS-PAGE. Presence of Amb a 1 was confirmed with Western immunoblot. Data were analysed using an analysis of covariance, with p < 0.05 considered significant.

Results: SDS-PAGE showed compositional changes in a ~26-30 kDa protein band under RT and not CT storage. The Amb a 1 concentration of the RT SLIT sample declined significantly over time, compared to that of the CT SLIT sample (F_(1,8) = 47.69, p < 0.0001). There was no significant difference in total protein concentration over time between groups (F_(1,8) = 1.79, p = 0.22).

Conclusions and clinical relevance: These results demonstrate that storage of glycerinated SLIT formulations in refrigerated CT preserved the highest concentration of the specific allergen Amb a 1, suggesting that SLIT formulations containing short ragweed should be stored under refrigeration.

Background: While alopecia associated with hair cycle arrest (HCA, Alopecia X) is well-recognised in Pomeranian dogs, the authors are unaware of reports of concurrent hair fragility.

Hypothesis/objectives: Following the observation of frequent hair shaft abnormalities in alopecic Pomeranians, we hypothesised that hair fragility events would be more frequent in dogs with a phenotype of HCA when compared to dogs with normal coats.

Animals: Eight alopecic Pomeranian dogs or crosses with a phenotype of HCA and 36 unaffected Pomeranians with owner-reported normal hair coats.

Materials and methods: All affected dogs underwent dermatological examination and clinicopathological evaluations. Hair samples, plucked from affected areas or obtained by brushing from unaffected dogs, were examined microscopically for structural abnormalities. Hair fragility events were characterised as trichorrhexis nodosa (TN) or longitudinal splits and were expressed per 10 mg of hair. A reference interval was calculated from the number of hair fragility events in the samples from unaffected dogs.

Results: The upper reference limit (with 90% confidence) from samples of 35 unaffected Pomeranians (one outlier excluded) was 9.75 hair fragility events per 10 mg of hair. The median (range) of fragility events in eight dogs with a phenotype of HCA was 66.0 (30.2-166.7) per 10 mg of hair.

Conclusions and clinical relevance: Clinicians should routinely perform trichography in Pomeranians with HCA because abundant hair abnormalities, particularly TN, may contribute to poor hair coat quality. Further studies are required to establish the pathophysiology of and treatments for these fragility events and to determine their predictive value for HCA.

Background: Canine atopic dermatitis (cAD) is a common skin disorder in dogs, wherein allergens are presumed to exert a significant influence. The prevalence of allergen sensitisation in dogs with suspected cAD remains inadequately investigated in France.

Hypothesis/objectives: This study aimed to analyse allergen-specific immunoglobulin (Ig)E test results from French dogs with suspected cAD, exploring potential risk factors influencing sensitisation.

Animals: The study included 25,451 client-owned dogs presented with clinical signs of cAD between January 2016 and December 2022. The study population consisted of 226 pure breeds and 915 cross-bred dogs of both sexes, with a mean age of 4.4 (±2.8) years.

Materials and methods: Data collection involved the compilation of results from canine serological allergen-specific IgE ELISA tests, using a 23 allergen composite panel. The influence of breed, sex, age, geographical area and sampling season on IgE test outcomes subsequently was analysed.

Results: Of the 25,451 analysed samples, 75.6% exhibited significant serum IgE concentrations in response to at least one of the tested allergens, with 67.9% testing positive for mites and 39.8% for pollens. Breed, sex, age, geographical area and sampling season were identified as significant risk factors influencing sensitisation patterns.

Conclusions and clinical relevance: This study provides insights into the prevalence and risk factors associated with allergen sensitisation in dogs with suspected cAD. Understanding these factors is crucial for effective diagnosis and tailored management strategies in veterinary practice. The findings underscore the need for personalised approaches in addressing cAD, considering individual patient characteristics.

Background: Alopecia X (AX) is a common noninflammatory alopecic condition of Pomeranian dogs with an unknown cause. While a genetic aetiology is suspected, no current tests can predict the development of this disorder or confirm the aetiology. Therefore, identifying potential risk indicators for the development of AX would be of value in this breed.

Objectives: This study aimed to identify risk indicators for AX in Pomeranians in the Netherlands and Belgium.

Materials and methods: A retrospective epidemiological study was conducted in the Netherlands and the Dutch-speaking parts of Belgium between March 2022 and August 2023, using an online survey of Pomeranian owners. Variables such as sex, birth season, neutering status, coat type, coat colour, grooming frequency and whether the dog experienced an 'ugly stage' of hair coat growth or not were recorded, along with the presence or absence of alopecia and the age of onset of the condition.

Results: Of 234 completed surveys, 211 were eligible for analysis. Statistical analysis with a Cox proportional-hazard model indicated that the risk of developing alopecia was greater for a woolly versus shiny coat and for males versus females.

Conclusions and clinical relevance: A woolly hair coat type and male sex were identified as risk indicators for developing AX in Pomeranian dogs in this study.

Background: Itch is a common clinical sign in skin disorders. While the neural pathways of itch transmission from the skin to the brain are well understood in rodents, the same pathways in dogs remain unclear. The knowledge gap hinders the development of effective treatments for canine itch-related disorders.

Hypothesis/objectives: This study aimed to investigate the differential gene expression in the dorsal root ganglia (DRGs) between healthy and atopic dogs to identify specific molecules potentially involved in itch signalling and neuroinflammation in canine atopic dermatitis (cAD).

Animals: Two atopic and four healthy dogs.

Materials and methods: DRGs were collected from atopic and healthy dogs to compare their transcriptional profiles using RNA sequencing.

Results: Principal component and heatmap analyses revealed two distinct clusters separating atopic from healthy dogs. Consistent with this observation, we identified 627 (543 upregulated and 84 downregulated) differentially expressed genes (DEGs) in atopic compared with healthy dogs. We further narrowed down our genes of interest to common DEGs in each atopic dog, which revealed 159 (132 upregulated and 27 downregulated) DEGs. Among these genes, when we focused on itch signalling-associated molecules, P2RY12, IL-2RG, TLR1 and POSTN were significantly upregulated, while MRGPRD and LPAR3 were both significantly downregulated in atopic dogs compared with those in healthy dogs. Pathway analysis showed a significant upregulation of CREB signalling in neurons, myelination signalling and neuroinflammation signalling pathways in atopic dogs.

Conclusions and clinical relevance: Our study suggested that dysregulation of neuroinflammatory pathways might play a role in the pathomechanism of cAD as in humans.

Background: Antimicrobial resistance is increasing each year. For example, in 2019 it was directly responsible for an estimated >1 million deaths. Additionally, the development of new drugs is much slower, generating enormous concerns about responses to infection in the future health scenario. Therefore, probiotics have emerged as an alternative to antibiotics.

Objectives: This study aimed to isolate and identify a Lactobacillus casei from healthy canine skin and investigate its antimicrobial effect on isolates of Staphylococcus pseudintermedius originating from dogs with pyoderma.

Materials and methods: L. casei was isolated from skin samples collected with a sterile cotton swab from the inner pinnae of healthy dogs. It was then cultured, identified using matrix-assisted laser desorption ionisation time-of-flight mass spectrometry, and tested against 30 different clinical isolates and one American Type Culture Collection strain of S. pseudintermedius using the spot-on-the-lawn technique. Its safety was assessed through a modified Kirby-Bauer disc diffusion susceptibility test.

Results: L. casei inhibited the growth of all isolates of S. pseudintermedius. The mean value of the inhibition halo of all isolates was 11.3 mm. A significant positive correlation (Pearson's linear correlation = 0.444; p = 0.014) was noted between the inhibitory halos formed by L. casei on the S. pseudintermedius isolates and the halos produced by the tested antimicrobial discs on the same isolates. The L. casei strain demonstrated sensitivity to all tested antimicrobials.

Conclusions and clinical relevance: The study indicates that using commensal bacteria from canine skin, specifically L. casei, to control bacterial infections caused by S. pseudintermedius can be a promising complementary or alternative therapy to antibiotics relevant to animal and human health.

Background: Psittacines (parrots and their allies) are kept under human care as companion animals, live exhibit specimens in zoological institutions and occasionally as research subjects. Cutaneous disorders such as feather destructive behaviour (FDB) and pododermatitis are commonly noted in clinical reviews, case reports and text book chapters.

Hypothesis/objectives: To document the type, signalment associations and prevalence of cutaneous disorders in a large number of captive psittacines in an academic referral teaching hospital population.

Animals: Case population at a university veterinary teaching hospital.

Methods and materials: Retrospective study using computerised medical records of birds (psittacine and non-psittacine) examined between 1 January 1988 and 31 December 2021. Inclusion criteria were records of psittacines with dermatological diagnoses.

Results: Of 3472 psittacines, 1454 (41.9%) had cutaneous disease. Age was strongly associated with an increased risk of cutaneous diseases. The most common cutaneous disorders were pododermatitis (n = 729) and FDB (n = 528). Female sex and increased age were associated with significantly higher odds of FDB, as were the genera Cacatua (cockatoos), Psittacus (African grey parrots), Ara (macaws) and Agapornis (lovebirds). Increased age and the genus Agapornis also were associated with significantly higher odds of pododermatitis. The most common infectious disease was mite (presumed Knemidocoptes) infestation, almost exclusively seen in budgerigars; increased age was associated with significantly lower odds of having mites.

Conclusions and clinical relevance: Pododermatitis and FDB were the most common cutaneous disorders in psittacines. As 50% of psittacines with skin disease presented for nonskin concerns, clinicians should perform a dermatological examination regardless of the reason for presentation.

Background: Chronic and recurrent pyoderma in dogs is driving a growing interest in natural antimicrobial products that offer minimal adverse effects and avoid antibiotic resistance.

Objectives: Evaluate the safety and efficacy of dermatological products with antimicrobial peptides and plant extracts, comparing them to chlorhexidine + miconazole and cephalexin therapy for superficial pyoderma in dogs.

Materials and methods: Forty-five dogs with superficial pyoderma underwent clinical, cytopathological and microbiological diagnosis, and were randomly assigned to Group 1 (G1) treated with shampoo (two weekly baths) and lotion (twice daily on the affected areas) containing natural antimicrobials; Group 2 (G2) treated with two weekly baths using a therapeutic shampoo containing 2% chlorhexidine and 2.5% miconazole; or Group 3 (G3) treated with oral cephalexin 30 mg/kg twice daily. Staphylococcus spp. strains were identified using matrix-assisted laser desorption ionisation-time of flight mass spectrometry and pruritus Visual Analog Scale (PVAS)/lesion scores were evaluated on Day (D)0, D7, D14, D21 and D28.

Results: Statistical differences (p < 0.05) were noted between D0 and D28 in PVAS values and lesion scores for all groups. G1 had lower PVAS scores than other groups on D7 and D14 (p < 0.05) and lower lesion scores than G3 on D7. By D28, G1 and G3 had lower lesion scores than G2. Notably, G1 and G2 had no adverse effects, while 26% of G3 patients experienced gastrointestinal issues during therapy.

Conclusions and clinical relevance: This preliminary investigation of the new product (G1) suggests that it is effective, safe and a promising topical treatment for managing superficial pyoderma in dogs, offering an alternative to systemic antibiotics and topical antiseptic treatments.