Ear tip ulcerative dermatitis treated with oclacitinib in 25 dogs: a retrospective case series.

BACKGROUND: Ear tip ulcerative dermatitis (ETUD) is an uncommon clinical reaction pattern in canine dermatology. The lesions are suggestive of vascular damage which may be caused by inflammatory or noninflammatory diseases, and often are idiopathic. Therapeutic options for ETUD include topical glucocorticoids or tacrolimus, pentoxifylline, vitamin E, doxycycline, tetracycline and niacinamide, sulfonamides, glucocorticoids, ciclosporin and surgical correction. HYPOTHESIS/OBJECTIVES: The aims of this retrospective case series were to describe the clinical features and report response to treatment with oclacitinib in dogs with idiopathic, chronic ETUD. ANIMALS: Twenty-five privately owned dogs with unilateral or bilateral ETUD. METHODS AND MATERIALS: Cases of ETUD which were poorly responsive to conventional therapy and subsequently treated with oclacitinib, are summarised. All cases were tested for leishmaniosis by serological examination [indirect fluorescent antibody test (IFAT) or enzyme-linked immunosorbent assay (ELISA)]. Histopathological examination was performed in two cases. RESULTS: Serological results were negative for leishmaniosis in all dogs. Histopathological changes consistent with proliferative thrombovascular necrosis of the pinnae were documented in two cases. Oclacitinib, used at the standard dose range recommended for the treatment of canine atopic dermatitis, effectively resolved ETUD in 22 of 25 dogs within one to three months. Several of the dogs required prolonged use of twice daily dosing. CONCLUSIONS AND CLINICAL RELEVANCE: Oclacitinib should be included among the therapeutic options for ETUD, once infectious diseases have been ruled out.

In vitro activity of lactoferricin solution against Malassezia pachydermatis from otitis externa in dogs and cats.

BACKGROUND: Malassezia pachydermatis is a commensal organism of the skin, yet it may induce dermatitis and/or otitis. Lactoferricin (Lfcin) is an antimicrobial peptide obtained by the pepsin-mediated digestion of lactoferrin, a multifunctional innate-defence milk protein. The antibacterial activity of Lfcin is thought to cause alteration of bacterial membrane permeability, thus inducing cell death. OBJECTIVES: The aim of this study was to evaluate in vitro antifungal activity of different dilutions of Lfcin solution against M. pachydermatis strains isolated from ears of dogs and cats with otitis externa. METHODS AND MATERIALS: Fifty clinical Malassezia isolates from 40 dogs and 10 cats were tested. A dilution method in microtitre plates was used starting with a 20% Lfcin water solution. The different dilutions were 2:1 (13.3%), 1:1 (10%), 1:2 (6.7%), 1:5 (3.3%) and 1:10 (1.8%). Results were expressed as the value at which the growth of 50% (minimal fungicidal concentration MFC50 ) and 90% (MFC90 ) of yeast cells was inhibited. RESULTS: All strains showed susceptibility to 20% Lfcin solution (100%). With 1:5 and 1:10 dilutions corresponding to 3.3% and 1.8% Lfcin solutions, all strains showed resistance. The MFC50 and MFC90 values were observed at 13.3% and 20% Lfcin solutions. CONCLUSIONS AND CLINICAL RELEVANCE: The results indicated that Lfcin solution exhibits the antimicrobial activity specific to antimicrobial peptides. In particular, the 20% solution can be effective in killing M. pachydermatis isolated strains. Some susceptibilities also are evident at lower concentrations of ≤6.7% for four strains.

Acral congenital superficial dermal lymphatic malformations in two unrelated cats: clinicopathological, dermoscopic and ultrastructural findings.

BACKGROUND: Cutaneous vascular malformations (CVM) represent a spectrum of human diseases identified at birth or in paediatric patients and classified according to the type of vessel affected. Confusing classification in human medicine has led to misdiagnoses and frequent nomenclature revision. Cutaneous lymphatic malformations (CLM) are reported sporadically in humans. OBJECTIVE: To describe the clinicopathological findings of superficial dermal cutaneous lymphatic malformations (SDCLM) in two cats. ANIMALS: Two unrelated adult domestic short hair cats. METHODS: The two cats were evaluated clinically and with a dermoscope for recurrent swelling and presence of vesicles oozing serosanguineous fluid affecting the right and left hind foot, respectively, since birth. Skin biopsy specimens were collected for histopathological and immunohistochemical evaluation and electron microscopy. RESULTS: A CVM was suspected based on the age of onset, clinical signs, results of diagnostic imaging and histopathological findings. Dermoscopy was used to describe the alterations of the skin surface. The involvement of the lymphatic vessels was confirmed using immunohistochemical findings and electron microscopy. CONCLUSION AND CLINICAL IMPORTANCE: To the best of the authors' knowledge, this is the first description of the clinical, dermoscopic, histopathological and ultrastructural characteristics of SDCLM in cats resembling the human counterpart. SDCLMs are rare conditions and appropriate histopathological and immunohistochemical confirmation is required to avoid misdiagnosis and mistreatment.

Increased filaggrin-metabolizing enzyme activity in atopic skin: a pilot study using a canine model of atopic dermatitis.

BACKGROUND: Filaggrin (FLG) and its metabolites are essential for skin barrier function and hydration of the stratum corneum. Alteration of the FLG metabolism could be the basis for an abnormal skin barrier in allergic dogs. OBJECTIVES: To investigate the expression and distribution of calpain-1, caspase-14, furin and matriptase, four enzymes involved in FLG metabolism, in the skin of atopic and healthy beagles. METHODS: Skin biopsies were collected from four healthy and four atopic beagles before and after allergen exposure. The dogs were challenged for three consecutive days to mimic an acute exposure, or once weekly to mimic a chronic exposure to allergens. Skin biopsies were taken on days 0 (nonlesional), 3 and 10 in the "acute" model and on days 0 (nonlesional), 14 and 28 in the "chronic" model. Four healthy dogs were used as controls. Indirect immunofluorescence was used to analyse the distribution and the expression of FLG enzymes in a semi-quantitative manner. Five consecutive pictures/section were taken and the intensity analysed tracing the epidermis and using ImageJ on the traced areas. The enzymes' expression was compared between healthy and atopic nonlesional skin (Day 0) and over time in each group. RESULTS: All enzymes were expressed in all layers of the epidermis. A significantly higher expression of calpain-1 (P = 0.028), caspase 14 (P = 0.028) and matriptase (P = 0.028) was evident in atopic compared to control dogs on Day 0. No differences over time were seen for any enzyme analysed. CONCLUSIONS AND CLINICAL IMPORTANCE: This preliminary study suggests an abnormal catabolism of FLG in canine atopic skin.

Randomized, double-blinded, placebo-controlled pilot study on the effects of topical blackcurrant emulsion enriched in essential fatty acids, ceramides and 18-beta glycyrrhetinic acid on clinical signs and skin barrier function in dogs with atopic dermatitis.

BACKGROUND: Lipid-based emulsions can be useful for the management of canine atopic dermatitis (cAD). 18-beta glycyrrhetinic acid (GRA), a component of liquorice root, has anti-inflammatory and anti-pruritic effects. HYPOTHESIS/OBJECTIVES: To evaluate the effects of a topical lipid emulsion containing ceramides, fatty acids and GRA on clinical signs of cAD and skin barrier in a randomized, double-blinded, placebo-controlled trial. METHODS: Client owned (n = 45) dogs with nonseasonal, mild/moderate AD, received either treatment or placebo for three months. Skin lesions, pruritus, transepidermal water loss (TEWL) and global assessment (GA) were evaluated. RESULTS: Fourteen dogs receiving treatment and 14 receiving the placebo completed the study. After one month ≥50% reduction in pruritus was seen in seven of 14 dogs (50%) in the Treatment group, and in two of 14 dogs (14.3%) in the Control group (P = 0.047). After two and three months, significant reduction in pruritus was not seen. For Canine Atopic Dermatitis Extent and Severity Index (CADESI), TEWL and GA, there were no significant findings over time or between groups. CONCLUSIONS AND CLINICAL RELEVANCE: The emulsion had some transient beneficial clinical effects. However, it was not effective in controlling pruritus as a monotherapy. Further studies should examine whether owner compliance was a factor in the steady decline of effect on pruritus scores. Further studies evaluating its role as an adjunctive therapy are indicated.

Lymphocyte subpopulations and Treg cells in dogs with atopic dermatitis receiving ciclosporin therapy: a prospective study.

BACKGROUND: Canine atopic dermatitis (CAD) is a chronic dermatological disease partly due to dysregulation of the immune system. Inappropriate activation of CD4(+) lymphocytes could favour and promote the allergic response. An inadequate activation system of regulatory T cells (Tregs) is suspected to be a key immunological feature of the allergic response in atopic dogs. HYPOTHESIS/OBJECTIVES: To evaluate the difference in the CD4/CD8 lymphocyte ratio and the percentage of Tregs in healthy dogs, in a breed predisposed to CAD, and in dogs affected by CAD before and during therapy with ciclosporin (CsA). Additionally to assess the improvement in pruritus and skin lesions during therapy with CsA, and to compare this with CD4/CD8/Treg values. ANIMALS: Ten atopic dogs of different breed, sex and age, ten healthy dogs and ten English bulldogs were included. METHODS: Peripheral blood from all dogs was tested using flow cytometry to assess the CD4/CD8 ratio and percentage of Tregs. For atopic dogs, sampling was repeated after 30 and 90 days of therapy with CsA. RESULTS: The CD4/CD8 ratio was not significantly different between the three groups. The Treg percentage was higher, but not statistically significant, in atopic dogs compared with controls. Therapy with CsA led to clinical improvement; it was not associated with statistically significant differences in haematological variables. CONCLUSION AND CLINICAL IMPORTANCE: This study suggests that Tregs may be involved in the pathogenesis of CAD and that ciclosporin therapy does not affect the circulating lymphocyte subpopulations.

Identification by real-time PCR with SYBR Green of Leishmania spp. and Serratia marcescens in canine 'sterile' cutaneous nodular lesions.

BACKGROUND: Noninfectious, non-neoplastic, nodular to diffuse, so-called 'sterile' granulomatous/pyogranulomatous skin lesions (SGPSLs) are infrequently identified in dogs and may represent a diagnostic challenge. Their correct identification is based on history, histopathology and absence of intralesional foreign bodies and micro-organisms. HYPOTHESIS/OBJECTIVES: The aim of this study was to investigate the presence of Leishmania spp., Mycobacterium spp., Serratia marcescens and Nocardia spp. by real-time PCR in canine nodular skin lesions histologically diagnosed as putatively sterile. METHODS: Formalin-fixed skin biopsies were collected from 40 dogs. All samples were associated with an SGPSL diagnosis characterized by multifocal, nodular to diffuse, periadnexal and perifollicular pyogranulomas/granulomas. Neither micro-organisms nor foreign bodies were detected with haematoxylin and eosin staining, under polarized light. Further analyses included periodic acid Schiff, Ziehl-Neelsen, Fite Faraco, Giemsa and Gram histochemical stains; anti-Bacillus Calmette-Guérin (BCG) and Leishmania spp. immunohistochemistry; and real-time PCR analysis for Leishmania spp., Mycobacterium spp., S. marcescens and Nocardia spp. RESULTS: Special stains and BCG/immunohistochemistry were negative in all samples. Real-time PCR was positive for Leishmania spp. in four of 40 biopsies and for S. marcescens in two of 40 samples. Real-time PCR for Mycobacterium spp. and Nocardia spp. was negative. No correlation between real-time PCR positivity and a specific histological pattern was identified. CONCLUSIONS AND CLINICAL IMPORTANCE: Leishmania spp. have been previously identified as possible agents of certain SGPSLs, while the involvement of S. marcescens has not been investigated previously. According to our findings, Serratia spp. should be included in the list of agents possibly associated with a subgroup of granulomatous/pyogranulomatous skin lesions in dogs.

Feline trombiculosis: a retrospective study in 72 cats.

BACKGROUND: Trombiculosis is the infestation of a host by the larval form of mites belonging to the Trombiculidae family. Few data are available regarding this infestation in cats. HYPOTHESIS/OBJECTIVES: The aim of this retrospective study was to report data, clinical signs, diagnostic and therapeutic features of feline trombiculosis. METHODS: Clinical records of cats presented for dermatological examination or annual vaccination in Italy, from 2002 to 2012, were retrospectively searched using the key words trombiculosis, cat and Neotrombicula. RESULTS: Seventy-two indoor/outdoor domestic short-hair cats with infestation by Neotrombicula autumnalis were enrolled. Pruritus was reported by the owners in 43% of cases, while 57% of cats were asymptomatic. The most common clinical signs included sudden onset of pruritus and the appearance of orange-coloured granules on the skin. Mites were found incidentally in 12 cats. The larvae were localized in multiple sites in 68% of cases. The most frequently affected area was the ear (80.5% of cases). Mites were more often identified in autumn (41 cases). Eleven cats were diagnosed during winter, 13 in spring and seven in summer. CONCLUSIONS AND CLINICAL IMPORTANCE: This retrospective study suggests that feline trombiculosis is probably underestimated as a cause of pruritus and dermatological lesions. Epidemiological data regarding this infestation in cats are still lacking, and it will be interesting to perform a multicentre study to increase knowledge of this disease.

Transepidermal water loss in healthy and atopic dogs, treated and untreated: a comparative preliminary study.

An impaired skin barrier function is thought to be crucial for allergic sensitization. In humans, the skin barrier is assessed by noninvasive methods, such as the measurement of transepidermal water loss (TEWL). Although limitations have been reported, measurement of TEWL has been demonstrated to be a suitable method to assess barrier function indirectly in dogs. The purposes of this prospective clinical study were twofold. The first aim was to evaluate and compare TEWL in healthy and atopic dogs. The second aim was to evaluate TEWL in a population of atopic dogs and to assess TEWL in dogs whose disease was in remission after successful therapy and compare it with dogs whose disease was not controlled or receiving treatment. One hundred and fifty dogs were selected and divided into the following three groups: 50 atopic dogs before specific treatment (group A); 50 in remission (group B); and 50 control dogs (group C). The mean values for TEWL for each group were 22.47 (g/m(2) h) (group A; 95% confidence interval 20.85-24.09), 12.57 (g/m(2) h) (group B; 95% confidence interval 11.43-13.7) and 8.81 (g/m(2) h) (group C; 95% confidence interval 8.09-9.52); P-value was 0.0001 for TEWL (groups A, B and C). This study showed a significant difference of TEWL between healthy control dogs and dogs with atopic dermatitis. Additionally, TEWL was lower in atopic dogs whose disease was in remission due to treatment. These results were consistent with reports in human medicine about TEWL.

Comparable efficacy of a topical 0.0584% hydrocortisone aceponate spray and oral ciclosporin in treating canine atopic dermatitis.

This study compared the efficacy of a 0.0584% hydrocortisone aceponate (HCA) spray (Cortavance(®); Virbac SA) and ciclosporin (Atopica(®); Novartis Animal Health) in canine atopic dermatitis in a single-blind randomized controlled trial. Dogs received HCA (two sprays/100 cm(2); n=24) or ciclosporin (5 mg/kg; n=21). Canine Atopic Dermatitis Extent and Severity Index (CADESI)-03, pruritus (visual analog scale with grade descriptors) and owner scores (5-point scales) were recorded every 28 days for 84 days. Intention-to-treat data were analysed. CADESI-03 and pruritus significantly decreased over time (P<0.0001), but there was no difference between the treatment groups (P=0.91 and P=0.52, respectively). Similar proportions of HCA- and ciclosporin-treated dogs achieved ≥50% reductions in CADESI-03 and pruritus scores at 28 days (CADESI-03 58.3 and 57.1%, P=0.76; pruritus 33.3 and 38.1%, P=1.0), 56 days (CADESI-03 70.8 and 81.0%, P=1.0; pruritus 62.5 and 57.1%, P=1.0) and 84 days (CADESI-03 75 and 85.7%, P=0.72; pruritus 65.2 and 57.1%, P=0.76). The CADESI-03 and pruritus scores were close to equivalence (0.47 and 0.51, respectively). By 84 days, every-other-day or twice-weekly therapy was achieved in 13 of 24 HCA- and 12 of 21 ciclosporin-treated dogs (P=0.85). There were no significant differences in scores for efficacy (P=0.82), tolerance (P=0.62) and ease of administration (P=0.25). Scores for tolerance (0.49) and administration (0.46) were close to equivalence. The score for efficacy favoured HCA (0.68). Mild adverse events were noted in six of 21 ciclosporin and none of 24 HCA dogs (P=0.008). Five HCA-treated dogs and three ciclosporin-treated dogs were prematurely withdrawn (P=0.7). In conclusion, HCA and ciclosporin proved equally effective in treating canine atopic dermatitis for up to 84 days.

Detection of feline herpes virus 1 via polymerase chain reaction and immunohistochemistry in cats with ulcerative facial dermatitis, eosinophilic granuloma complex reaction patterns and mosquito bite hypersensitivity.

Ulcerative dermatitis caused by feline herpes virus 1 (FHV-1) is an uncommon disease characterized by cutaneous ulcers secondary to epidermal, adnexal and dermal necrosis. Differential diagnoses for FHV-1 lesions include, but are not limited to, mosquito bite hypersensitivity and eosinophilic granuloma complex. Histopathological diagnosis of FHV-1 dermatitis is based on the detection of the intranuclear inclusion bodies. In cases where intranuclear inclusions are missing but clinical and histological findings are compatible with FHV-1 dermatitis, immunohistochemistry (IHC) and PCRs have been used. In this retrospective study, we evaluated the presence of FHV-1 by IHC and PCR in skin biopsies and compared the results of the two tests. Sixty-four skin biopsy specimens from cats with compatible lesions were reviewed and tested via PCR and IHC for evidence of FHV-1. Polymerase chain reaction was positive in 12 of 64 biopsies; PCR and IHC were positive only in two of 64 biopsies, and these cases were considered true positive cases. The higher number of PCR-positive cases was possibly attributed to amplification of viral DNA from a live attenuated vaccination, but a previous FHV-1 infection with subsequent amplification of latently inserted FHV-1 could not be excluded. If clinical signs and histopathology suggest FHV-1 infection in the absence of typical inclusion bodies, IHC is the preferred diagnostic test; PCR may be useful for initial screening, but due to false positives is not sufficient for a definitive diagnosis.

Quality of life of dogs with skin disease and of their owners. Part 2: administration of a questionnaire in various skin diseases and correlation to efficacy of therapy.

A previously validated 15-item questionnaire on dogs' life quality (QoL1) and that of their owners (QoL2) was applied in a multicentre study to owners of 200 dogs with different dermatological conditions, together with a question on the owner-perceived disease severity (S). Factor analysis was applied to the whole questionnaire. The correlation of S with QoL1 and QoL2 scores was evaluated using Spearman's rank correlation tests. Owner sex, age, educational level and willingness to pay for a potential definitive cure of the disease were recorded, and compared with quality of life (QoL) scores. In 23 atopic dogs, CADESI-03, pruritus Visual Analogue Scale and QoL scores were obtained before and after therapy, and their correlation was evaluated with linear regression. Factor analysis revealed that three factors (S, QoL1 and QoL2) explained 75% of the variance. Owner-perceived severity correlated significantly with QoL1 and QoL2 (P = 0.002 and P = 0.015, respectively). The five diseases with the worst QoL scores were scabies, pododermatitis, complicated atopic dermatitis, pemphigus foliaceus and endocrine alopecia. Pruritic diseases did not give significantly higher QoL1 or QoL2 scores compared with nonpruritic diseases (P = 0.19, Kruskall-Wallis test). Owner sex, age or educational level did not influence QoL scores. Female sex, a younger age and a higher educational level were significantly associated with more willingness to pay. In atopic dogs, all the scores decreased after therapy, but post-treatment CADESI-03 and Visual Analogue Scale scores did not correlate with QoL1 and QoL2. Questions related to the burden of maintenance therapy showed the lowest improvements in score.

Sublingual reactive histiocytosis in a dog.

Lingual lesions are relatively uncommon in dogs and are mostly represented by neoplasms and glossitis secondary to trauma or infections. Reactive histiocytosis is an uncommon, poorly understood, reactive disorder characterized by proliferation of activated, interstitial, dendritic, antigen-presenting cells associated with lymphocytes and neutrophils with a specific angiocentric orientation and occasional angioinvasion and angiodestruction. Clinically, the disease has a waxing and waning behavior with possible response to treatment and regression, or progression to multiple lesions and internal organ involvement. This case report describes an unusual sublingual presentation of reactive histiocytosis in a Miniature Pinscher dog. The diagnosis was obtained by clinical and histopathological exclusion of other causes, detection of the characteristic microscopic growth pattern, and by immunocytochemistry. Histiocytic cells were vimentin, CD18, CD11c, and CD1c positive consistent with a dendritic cell origin. Anti-BCG stain (Bacillus Calmette and Guerin) was negative for etiological agents. The dog was treated with oral administration of tetracycline and niacinamide during an 8-month period. There was no indication of recurrence of the sublingual mass 2-years following treatment.

A case of drug-resistant staphylococcal para-aural abscess treated with photodynamic therapy in a West Highland White Terrier presenting with chronic otitis and craniomandibular osteopathy.

A 10-year-old canine with chronic unilateral otitis and a history of unsuccessful systemic and topical antibiotic treatments was referred. A computer tomography scan (CT scan) revealed unilateral chronic otitis with calcification of the ear canal, abscessation and fistula. On bacterial culture a Staphylococcus pseudintermedius sensitive to pradofloxacin was isolated. Systemic treatment with pradofloxacin, 3 mg/kg per os once daily, improved the infection and the dog had total ear canal ablation and bulla osteotomy performed. After one month, despite antibiotic treatment new fistulas developed in the same area. Bacterial culture revealed an drug-resistant S. pseudintermedius sensitive only to rifampicin. Under general anesthesia, the area was cleaned with 0.5% saline solution and 1 mL of indocyanine green (Emundo®, A.R.C.) was injected into the fistulas. A treatment with diode laser (A.R.C. Laser 810 nm, GmbH, Nurnberg, Germany) of four cycles 500 mw for 30 s, with a dosage of 50 J/cm2 in the effected area was performed. No antibiotic was administered and one week later, 50% of the fistulas were closed with a significant improvement of the patient's clinical condition. Cytology and bacterial culture were negative 72 h after the treatment. Total recovery occurred after two weeks. Photodynamic Therapy(PDT) is a promising antibacterial technique in case of localized refractory bacterial infections.

Effects of Feeding a Hypoallergenic Diet with a Nutraceutical on Fecal Dysbiosis Index and Clinical Manifestations of Canine Atopic Dermatitis.

BACKGROUND: an imbalance of the intestinal microbiota can cause health problems in the gastrointestinal tract and in other organs. Canine Atopic Dermatitis (CAD) is a genetically predisposed, inflammatory and pruritic allergic skin disease with multifactorial etiology and multimodal treatment. The aim of this study was to assess the effect of a nutraceutical product on Dysbiotic Index (DI) and the skin lesions of atopic dogs. METHODS: a nutraceutical product was administered to 32 dogs with CAD. The product was associated with a standardized hypoallergenic diet for 60 days; the dietary regimen continued for 120 days, while ongoing therapies remained unchanged. Values of Visual Analogic Scale (VAS), Canine Atopic Dermatitis Lesional Index (CADLI) and DI were evaluated on day 0, 60, 120. RESULTS: all the 32 dogs showed a statistically significant decrease (p < 0.001) to V60 of VAS and CADLI, which persisted and increased to V120 when diet alone was continued. The decrease in the DI value was also statistically significant (p < 0.001). CONCLUSION: the intake of nutraceutical associated with diet resulted in a decrease in the index of intestinal dysbiosis, with an improvement in the subjective severity of cutaneous lesions.

Canine nodular dermatophytosis (kerion): 23 cases.

Dermatophytosis is a common zoonotic disease, and one of its clinical presentations in the dog is nodular dermatophytosis (kerion). Because the infection is located within the dermis, routine diagnostic tests such as a Wood's lamp examination, microscopic examination of hair shafts for fungal elements and fungal culture can yield negative results. In such cases, histopathological examination with routine and special stains (periodic acid-Schiff, Gomori methenamine silver) is required to confirm the diagnosis. Nodular dermatophytosis in 23 dogs of different breed, age and sex with single or multiple nodules is described. Twelve dogs had a single nodule, and 11 dogs showed multiple lesions. Wood's lamp examination was negative in all cases. Microscopic examination of plucked hairs showed arthrospores in 8 of 23 cases. Skin scrapings in mineral oil looking for arthrospores and/or hyphae were positive in 12 cases. Impression smears of exudates were diagnostic in 21 of 23 cases (91%), showing arthrospores within fragments of hair shafts or free among neutrophils and macrophages (pyogranulomatous inflammation). Histopathology was performed in two cases. Fungal culture was positive for Microsporum canis in 16 dogs and for Microsporum gypseum in one dog. In six cases, the causative agent was not identified by fungal culture. All dogs were treated with systemic antifungal therapy and in eight cases with concurrent antibiotic therapy. Nodular dermatophytosis resolved in all dogs with the prescribed treatments within 4 to 8 weeks. Transmission to people or other pets in the home was not found.

Prevalence of PNPLA1 Gene Mutation in 48 Breeding Golden Retriever Dogs.

A non-epidermolytic ichthyosis has been identified in Golden Retrievers due to a variant in the PNPLA1 gene, and a genetic test is available to detect wild-type, heterozygous and homozygous dogs. The aims of this study were to investigate the prevalence of the PNPLA1 gene variant in Golden Retrievers used for breeding and to provide more information to breeders in order to restrict the spread of this disease. Clinical examination and assessment of the PNPLA1 genotype using PCR testing of oral swabs were performed in 48 breeding Golden Retrievers. Wild-type, heterozygous or homozygous variants of the PNPLA1 gene were demonstrated in 10 (21%), 23 (48%), and 15 (31%) of the 48 dogs, respectively. In only 3 of the 48 dogs were clinical signs suggestive of ichthyosis identified. Data collected agreed with data reported in the literature. The high prevalence of homozygous and heterozygous variants makes the exclusion of mutated dogs from breeding impractical. Furthermore, the reliability of the PNPLA1 mutation in prediction of clinical signs of ichthyosis is unclear. Additional studies are needed to investigate if PNPLA1 is the only gene involved or if other genes and environmental factors have a role in the development of ichthyosis in Golden Retrievers.

Comparison of 4 fixation and staining methods for the cytologic evaluation of ear canals with clinical evidence of ceruminous otitis externa.

BACKGROUND: Swab cytology of ear canals is one of the most useful and rapid methods to assess the presence of external ear infections. Smears are generally stained with rapid Romanowsky-type stains, with or without prior heat fixation. OBJECTIVES: The aim of this study was to compare 4 different methods of fixation and staining of ear swab cytology samples from dogs. METHODS: Eight dogs with otitis externa were selected from a dermatology referral population. A cotton swab was used to obtain ceruminous material from 12 ear canals. Four smears of each swab were prepared on glass slides (randomly identified as A, B, C, or D) and air-dried for cytologic examination. Samples marked A were stained with Dip Quick (Jorgensen Laboratories Inc, Loveland, CO, USA) after heat fixation; samples marked B were stained without heat fixation; samples marked C were heat-fixed and dipped only in the counterstain (the blue reagent) of Dip Quick; and samples marked D were dipped only in the counterstain, without heat fixation. Ten high-power fields (hpf; X100 oil immersion objective) in each slide were evaluated by 2 observers, and total numbers of keratinocytes, yeast, bacteria, and neutrophils were counted. Statistical comparison was performed using an ANOVA model applied after verifying the normal distribution of the data, and using nonparametric sign tests and Wilcoxon signed rank tests. RESULTS: No statistically significant differences were observed in the numbers of keratinocytes, yeast, bacteria, or neutrophils among the 4 staining methods (P > .05), although significant interobserver differences were found. CONCLUSION: We conclude that heat fixation does not improve the quality of ceruminous ear swab samples for cytologic evaluation, and propose a 1-step dip in the blue reagent alone as a rapid method of staining samples from canine ear canals.