Veterinary dermatology最新文献

Background: Autosomal recessive ichthyosis leads to structural or biochemical changes that impair skin barrier function.

Hypothesis/objectives: To assess (1) the phenotype and genotype in a litter of Jack Russell Terriers with autosomal recessive congenital ichthyosis (ARCI), and (2) the defective skin barrier and determine if a topical ceramide can modulate the barrier.

Animals: A healthy dam and litter of Jack Russell Terrier puppies (healthy male, affected male and female), one affected adult Jack Russell Terrier and one unrelated healthy Jack Russell Terrier.

Materials and methods: A severe cornification defect was identified via examination of affected puppies. As the phenotype worsened, the affected puppies received a topical application of ω-0-acylceramide for 10 days. Before humane euthanasia, the skin barrier was evaluated via transepidermal water loss (TEWL), corneometry and pH in affected dogs. Genomic testing was performed, and skin samples were analysed by light and electron microscopy.

Results: Affected puppies were homozygous for the 1980 bp LINE-1 insertion in the TGM1 (transglutaminase 1) gene; the unaffected littermate and the dam were heterozygous carriers. ARCI puppies were underweight and had a severe hyperkeratotic phenotype that impaired mobility. TEWL was markedly higher in affected dogs. The cutaneous pH of affected puppies was higher than the normal littermate. Treatment of the skin with ω-0-acylceramide normalised the pH to match the littermate and decreased TEWL. Electron microscopy revealed marked attenuation of the cornified envelope.

Conclusions and clinical relevance: Dogs with TGM1-deficient ARCI have an impaired skin barrier. Topical therapy can partially repair the barrier defect.

Background: Cold atmospheric plasma (CAP) is a new therapeutic tool used to treat various skin diseases in humans and animals.

Objective: To evaluate the effect of CAP in the treatment of canine acute otitis externa (AOE).

Animals: Four client-owned golden retriever dogs with bilateral AOE.

Methods and materials: After cleaning with a commercial ear cleanser, right ears (STANDARD group) were treated with an antibiotic/antifungal/corticosteroid combination and left ears (CAP group) were treated with CAP every three days for a total of four treatments. Cytological score and otitis index score (OTIS)3 were recorded for each ear on Day (D)0, D10 and D15. At D10 and D15, owners and investigators recorded an overall assessment.

Results: In both groups, OTIS3 and cytological score decreased over the study period. The overall assessment scale ranged from moderate to excellent in both groups.

Conclusions and clinical relevance: Cold atmospheric plasma treatment showed equal therapeutic effect compared with a commercial topical anti-inflammatory and antimicrobial ear treatment.

Background: Lokivetmab, a caninised monoclonal antibody against interleukin (IL)-31, is an effective treatment for the pruritus associated with canine atopic dermatitis (cAD).

Objectives: To investigate the efficacy and safety of lokivetmab during long-term treatment defined as at least three consecutive lokivetmab injections in atopic dogs under field conditions. To assess individual factors influencing treatment outcome and adverse events.

Animals: 150 dogs with cAD.

Materials and methods: Medical records of dogs treated with lokivetmab were reviewed, and owners and/or veterinarians were contacted as needed for follow-up. A decrease of the pruritus Visual Analog Scale (PVAS) score by ≥2 or a PVAS score ≤2 after treatment was considered as treatment success. Logistic regression was used to investigate the influence of a variety of factors on outcome: type of cAD (food versus environment), age at first lokivetmab administration, disease chronicity, dosage and/or secondary infection. Any adverse event that occurred during the study period was recorded.

Results: Lokivetmab reduced the PVAS score with long-term use (p < 0.01); the success rate was 53 of 69 total dogs (77%). The probability of treatment failure decreased with increasing treatment duration. None of the factors investigated influenced the treatment outcome. Twelve dogs of 150 (8%) showed adverse events such as gastrointestinal signs or lethargy.

Conclusion and clinical relevance: Lokivetmab appears to be an effective and safe long-term anti-itch therapy for dogs with cAD.

Background: Otitis externa (OE) is one of the most frequently diagnosed dermatological diseases in dogs, having a multifactorial aetiology. Among the bacterial agents associated with canine OE, Pseudomonas aeruginosa is of special concern owing to its frequent multidrug resistance profile and ability to form biofilms related to the infection's chronicity and recurrence.

Objectives: The main objective of this study was to evaluate and compare the antibiofilm activity of two innovative antimicrobials-an otological gel containing a synthetic antimicrobial peptide and Lavandula angustifolia essential oil-with gentamicin (a conventional antibiotic) using biofilm-producing P. aeruginosa isolates obtained from dogs with OE.

Materials and methods: The biofilm eradication capacity of gentamicin, otological gel and lavender oil was determined against a collection of 12 P. aeruginosa biofilm-producers among 35 clinical isolates obtained from the ear canals of dogs with OE. Also, the antimicrobial activity of the otological gel against P. aeruginosa biofilms was assessed in an in vitro model of dog cerumen.

Results: Lavender oil showed the best effectiveness after 30 min of contact, eradicating 58.3% (seven of 12) of the isolates, and gentamicin showed full eradication (12 of 12) after 24 h. The otological gel acted more slowly than the lavender oil; yet at 24 h, the antibiofilm capacity of both compounds was similar, with no significant difference between them. It also was found that triglycerides from synthetic cerumen earwax had antipseudomonal activity and, when combined with the otological gel, led to the full eradication of P. aeruginosa.

Conclusions and clinical relevance: The results of this in vitro study indicate that lavender oil and the otological gel may be effective topical treatments for canine OE promoted by P. aeruginosa biofilm-producers, as alternatives to gentamicin.

Background: Ear cleaning is often recommended for management of canine otitis externa (OE). Few in vivo studies evaluate how ear cleaning affects treatment outcome.

Hypothesis/objectives: To determine the effect of ear cleaning on canine OE by comparing treatment outcome in cleaned versus noncleaned ears.

Animals: Twenty-three client-owned dogs with ceruminous or purulent OE.

Materials and methods: Forty ears were randomised to one of two groups: 20 ears were wiped with dry or saline-moistened gauze (grp1), and 20 external ear canals received manual cleaning (grp2) with a commercial product. One millilitre of a commercial otic suspension containing hydrocortisone aceponate, miconazole nitrate and gentamicin sulfate was applied to affected ears every 24 h for five days. Cytological scores, modified otitis index score (OTIS3), pruritus Visual Analog Scale (PVAS), modified PVAS and client questionnaire were compared on Day (D)0 and D7.

Results: There were no statistical differences between cytological scores, modified OTIS3, PVAS, modified PVAS or client assessments between groups at D7. Both groups had significant reduction in all treatment parameters from D0 to D7 with the exception of cytological rod scores that were only significantly decreased in cleaned ears. There was a significant difference in OTIS3 before and after cleaning on D0.

Conclusions and clinical relevance: Both groups achieved successful outcome regardless of cleaning. Ear cleaning may be more important when rod-shaped bacteria are present.

Background: Mycobacterium cell wall fraction (MCWF) is derived from nonpathogenic Mycobacterium phlei and is used as an immunomodulatory compound in clinical practice, yet its mode-of-action requires further research.

Objective: To evaluate the host response to MCWF in canine peripheral blood mononuclear cells (PBMCs) by using enzyme-linked immunosorbent assays (ELISA) and quantitative reverse transcription (qRT)-PCR for assessment of cytokines.

Animals: Eight healthy Labrador retrievers.

Materials and methods: PBMCs were isolated from whole blood using density centrifugation. The cells were cultured with different concentrations of MCWF or a potent stimulator of cytokine production, phorbol 12-myristate 13-acetate/ionomycin, or left in cell culture medium for 24, 48 and 72 h. Cytokines were measured by ELISA for interleukin (IL)-4, IL-10 and interferon-gamma (IFN-γ), and by qRT-PCR for IL-4, IL-10, IL-13, IFN-γ, tumour necrosis factor alpha (TNF-α) and transforming growth factor-beta.

Results: A significant increase of IL-10 messenger ribonucleic acid (mRNA) was detected at all time points for all concentrations of MCWF (p < 0.05). Protein analysis reflected this finding, with a maximum IL-10 concentration of 300.6 ± 38.3 μg/mL. Compared to the negative control, post-stimulation elevation of IFN-γ mRNA was noted at 24 h with all concentrations of MCWF (p < 0.01), and TNF-α mRNA was increased for 0.5 μg/dL MCWF only at 72 h (p < 0.05).

Conclusions and clinical relevance: MCWF stimulation of PBMCs results in the elevation of both proinflammatory and regulatory cytokine mRNA. Further research into the role of MCWF as a systemically administered regulatory immunomodulator or adjuvant to allergen-specific immunotherapy should be considered.

Background: Sebaceous adenitis (SA) is an immune-mediated disease targeting the sebaceous glands. Meibomian gland dysfunction is a disease affecting meibomian glands with inflammatory features. Sebaceous and meibomian glands share anatomical, physiological and embryological similarities. The involvement of meibomian glands in dogs with SA is currently unknown.

Objectives: To evaluate meibomian glands in dogs affected by SA and compare them with healthy dogs.

Animals: Eighteen dogs were enrolled. Nine dogs with SA were retrospectively identified from clinical records and represented the case group. Nine healthy, breed- and age-matched dogs were prospectively enrolled in the control group.

Materials and methods: Both groups underwent dermatological examination, Schirmer tear test-1 (STT-1), tear meniscus height (TMH), slit-lamp biomicroscopy, interferometry (INT) and noncontact infrared meibography (NIM).

Results: One third of SA dogs presented subepithelial crystalline opacities. No significant difference between groups was observed in TMH (p = 0.944) and STT-1 values (p = 0.066). INT (p = 0.016) and NIM grades (p = 0.010) were significantly higher and lower in the SA group compared to the control group, respectively. INT values decreased with age (η = 0.930), while NIM scores (η = 0.935) increased.

Conclusions: Clinical Relevance: Subepithelial crystalline opacities in SA dogs might reflect a reduced tear film quality. In the absence of standardised methods, INT and NIM proved to be noninvasive and useful methods to examine meibomian glands. Dogs with SA showed a thinner lacrimal lipid layer and more severe meibomian gland abnormalities than control dogs, which seemed to progress with age.

Background: Protection from solar ultraviolet radiation (UVR) is paramount in light-skinned pig breeds such as Yorkshire or Landrace to avoid sunburn.

Objectives: Determination of the UVR exposure of a pig and the sun protection abilities of shade cloths with different shade rates.

Animals: Life-sized plastic model of a Landrace pig.

Materials and methods: The model was equipped with 20 UVR meters at various anatomical positions that recorded the erythemal effective solar irradiance. A turntable enabled irradiation from different directions. Solar irradiance was measured in direct sunlight as well as under three shade cloths with different shade rates (50%, 75% and 90%) and a camouflage net. The sun protection factors (SPF) were determined as the ratio of unshaded-to-shaded measurements at the same solar elevation. The exposure ratio to ambient (ERTA) was calculated for each body site with respect to ambient irradiance. It allows determination of when pigs are at risk of sunburn and protection is needed.

Results: The calculated ERTA values show that some body parts may receive higher values than ambient UVR. Measurements showed that the SPF of shade cloths depends on textile denseness. Selected shade cloths reached values of 3.5 (shade rate 50%), 4.2 (75%) and 5.8 (90%). Protection by the camouflage net was poor. The highest SPF was gained on body sides where ERTA was highest.

Conclusions and clinical relevance: Shade cloths can protect all body sites effectively and vulnerable sites in particular. The results of our study enable an estimation of when pigs are at risk of sunburn and provide quantitative metrics for sun protection. This allows effective prevention of UVR-caused skin damage and secondary disorders.

Background: Squamous cell carcinoma (SCC) is one of the most commonly diagnosed neoplastic disorders in reptiles. Recently, however, it has been demonstrated that basal cell carcinomas (BCCs) are frequently misclassified as SCCs. Several histological SCC and BCC variants have been characterised and their classification may allow the establishment of appropriate prognosis estimation and treatment approaches.

Hypothesis/objectives: To describe the clinical features and surgical outcomes of SCCs and BCCs diagnosed between 2010 and 2022 in reptiles.

Animals: Thirty-three captive reptiles (21 squamates and 12 chelonians).

Materials and methods: Detailed clinical history, including staging and surgical outcomes, were performed. Statistical analysis assessed significant factors using Prism (v8.2.1).

Results: While SCC was predominantly diagnosed in lizards, BCC was most commonly diagnosed in chelonians, and both neoplasms mainly occurred in adult to aged, male individuals. Although the gross pathological findings were highly comparable between SCC and BCC, considerable variation could be seen according to the primary location (oral, cutaneous or epidermis of the shell). Humane euthanasia or noncurative intent surgeries were performed in a minority of the cases. Curative intent surgeries were successful in 19 of 27 cases during a 1- to 7-year follow-up period, yet recurrence was seen in 8 cases. The results of this study allowed the identification of significant high-risk prognostic factors for SCC and BCC in reptiles.

Conclusions and clinical relevance: This study contributes to predicting the clinical behaviour and prognosis of distinct SCC and BCC histological variants, and selecting the most appropriate treatment protocol.

Background: Topical therapy is preferred for otitis externa (OE) in dogs. Otic products commonly contain glucocorticoids that can be systemically absorbed and possibly interfere with diagnostic tests such as intradermal testing (IDT).

Hypothesis/objectives: To determine the effect of a long-lasting otic solution containing mometasone furoate (MF) on IDT immediate reactions and to determine withdrawal time before IDT.

Animals: Seventeen dogs with healthy ears (Group 1) and 12 with OE (Group 2).

Materials and methods: Intradermal injections of histamine, anticanine-immunoglobulin (Ig)E and saline were subjectively and objectively evaluated before treatment and weekly for 6 weeks, after a single application of a long-lasting otic solution containing MF.

Results: Statistically significant reductions in the mean subjective histamine scores after application of MF were observed at Weeks 1 (p = 0.012) and 2 (p = 0.028) in Group 1, and Weeks 1 (p = 0.00066), 2 (p = 0.02) and 4 (p = 0.034) in Group 2. Mean histamine objective scores were significantly reduced in Weeks 1 (p = 0.042), 2 (p = 0.0009), 3 (p = 0.001) and 5 (p = 0.018) in Group 1 only. The mean subjective anticanine-IgE scores were significantly reduced in Week 1 in both groups (p = 0.003, p = 0.0066), respectively. There were no significant changes in the mean anticanine-IgE objective score in either group.

Conclusions and clinical relevance: Application of a long-lasting otic solution containing MF can interfere with IDT immediate reactions in healthy and OE dogs. Based on the subjective evaluation, IDT can be performed ≥2 weeks after application of the otic solution in healthy dogs, and ≥4 weeks in dogs with OE.