Bilateral pyogranulomatous otitis externa with putative cartilage destruction in a dog: A severe case of auricular chondritis?

Auricular chondritis of unknown cause was suspected in a 10-year-old male Bolognese dog with a five-month history of painful bilateral nodular and ulcerative pyogranulomatous dermatitis of the pinnae with putative auricular cartilage destruction. Pain and lesions resolved with immunosuppressive doses of prednisolone, yet the condition resulted in deformity of both pinnae and external canals.

Une chondrite auriculaire d'étiologie inconnue est suspectée chez un bichon bolonais mâle de 10 ans qui présente depuis 5 mois une dermatite pyogranulomateuse nodulaire et ulcéreuse bilatérale douloureuse du pavillon de l'oreille avec une destruction présumée du cartilage auriculaire. La douleur et les lésions disparaissent avec des doses immunosuppressives de prednisolone, mais l'affection entraîne une déformation des deux pavillons et des conduits auriculaires externes.

Suspeitou­se de condrite auricular de causa desconhecida em um cão macho Bolonhês de 10 anos de idade com um histórico de cinco meses de dermatite piogranulomatosa ulcerativa e nodular bilateral no pavilhão auricular com suposta destruição de cartilagem auricular. A dor e as lesões resolveram com doses imunossupressoras de prednisolona apesar de a etiologia ter resultado na deformidade de ambas as orelhas e condutos auditivos.

Se sospechó la existencia de una condritis auricular de causa desconocida en un perro boloñés de 10 años con historia de 5 meses de duración de una dermatitis nodular ulcerativa piogramulomatosa y bilateral en las orejas con posible destrucción del cartílago auricular. El dolor y las lesiones se resolvieron con dosis inmunosupresoras de prednisolona pero la enfermedad produjo deformación de ambas orejas y de los canales auriculares externos.

Canine pigmented viral plaques associated with application of potent topical glucocorticoids.

A six-year-old atopic boxer presented with pigmented viral plaques on the interdigital spaces and pinnae following treatment with potent topical glucocorticoids. The lesions regressed after treatment was discontinued, and recurred each time a topical glucocorticoid was resumed. A Chipapillomavirus was amplified from lesional tissue.

Prolonged twice-daily administration of oclacitinib for the control of canine atopic dermatitis: a retrospective study of 53 client-owned atopic dogs.

BACKGROUND: Oclacitinib administered at the licensed dose twice daily for two weeks and then once daily as required is recommended for the treatment of atopic dogs. In some cases, the once-daily regimen is insufficient to control the clinical signs. OBJECTIVES: To provide preliminary safety and efficacy data on the prolonged twice-daily administration of oclacitinib in atopic dogs. ANIMALS: Fifty-three client-owned atopic dogs. METHODS AND MATERIALS: The medical records of dogs with atopic dermatitis treated with oclacitinib twice daily for more than two weeks were reviewed retrospectively. Animal details, treatment dose and duration, concurrent diseases, adjunctive medications and possible adverse events were recorded. Treatment efficacy was assessed retrospectively and, when available, the selected blood parameters before and during the treatment were compared. Statistical analyses of the collected data were performed. RESULTS: The median treatment duration was 113 days. Excellent-to-good efficacy was observed in 38 dogs (72%), including 24 of 33 dogs that failed to respond to the once-daily regimen. Eight dogs showed a poor response despite the addition of systemic glucocorticoids. Pyoderma, gastrointestinal signs and otitis externa were the most frequent adverse events recorded whilst on treatment. Blood tests performed in 35 dogs showed slightly decreased leucocyte, neutrophil, eosinophil and monocyte counts that remained within the reference ranges in most cases. Three dogs developed hypercholesterolemia. CONCLUSIONS AND CLINICAL RELEVANCE: Prolonged twice-daily administration of oclacitinib generally was well-tolerated and was effective in most of the treated dogs. Regular clinical evaluation and blood tests are advisable for this treatment regimen.

Presumptive herpesvirus-associated erythema multiforme in a cat.

Erythema multiforme (EM), an uncommon immune-mediated skin disorder of cats, conceivably could be triggered by feline herpesvirus type-1 (FHV-1) infection, in a manner analogous to human herpesvirus-associated EM (HAEM). This report describes a 10-year-old Persian-mixed cat with a presumptive diagnosis of HAEM.

L'érythème polymorphe (EM), est une dermatose à médiation immune rare chez le chat, théoriquement déclenché par une infection FHV-1 (feline herpesvirus type-1), de la même façon que chez l'homme avec HAEM (human herpesvirus-associated EM). Cet article décrit un chat croisé Persan de 10 ans avec un diagnostic présumé de HAEM.

El eritema multiforme (EM), un trastorno cutáneo poco común mediado por el sistema inmunitario de los gatos que posiblemente podría desencadenarse por una infección por herpesvirus felino tipo 1 (FHV-1), de manera análoga a la EM asociada al herpesvirus humano (HAEM). Este informe describe un gato persa mixto de 10 años con un diagnóstico presuntivo de HAEM.

Eritema multiforme (EM), uma doença de pele imunomediada incomum em gatos, em teoria pode ser desencadeada por infecção por herpesvírus felino tipo 1 (FHV-1), de maneira análoga ao EM associado ao herpesvírus humano (EMAH). Este relato de caso descreve um gato persa de 10 anos de idade com diagnóstico presuntivo de EMAH.

Cryotherapy to treat benign skin tumours in conscious dogs.

BACKGROUND: Cryotherapy can be used to treat benign skin lesions without general anaesthesia. This technique has only been described in anaesthetized dogs. OBJECTIVE: To describe the feasibility, safety and efficacy of cryotherapy to treat benign skin tumours in conscious dogs. ANIMALS: Twenty-five client-owned dogs with 52 skin tumours diagnosed as benign sebaceous neoplasia (46) or follicular cysts (six). METHODS AND MATERIALS: Cryotherapy was performed in conscious dogs using a liquid nitrogen spray technique with a handheld spray-release system. If needed, cryotherapy was repeated every three to four weeks until complete cure was achieved or for a maximum of eight treatments. Effectiveness and adverse effects were recorded. RESULTS: Resolution was obtained for 29 of 52 lesions (57%) with a median number of one to two cryotherapy sessions. Eighteen of 52 (35%) lesions shrank to <0.1 cm. In one case, the tumour enlarged after cryotherapy, and histopathological examination of the excisional biopsy revealed an apocrine gland carcinoma. Pain and discomfort during the treatment were the most common adverse effects (33%). CONCLUSIONS AND CLINICAL IMPORTANCE: In the present study, cryotherapy was possible in conscious dogs and proved to be effective to cure or reduce the size of benign sebaceous tumours and follicular cysts. The procedure is safe but the degree of pain during the treatment needs to be further investigated. Worsening of the lesion after cryotherapy suggests the need for surgical removal and histopathological examination.

Genetic variant in the NSDHL gene in a cat with multiple congenital lesions resembling inflammatory linear verrucous epidermal nevi.

BACKGROUND: The feline counterpart of human inflammatory linear verrucous epidermal nevus (ILVEN) has been described; however, the possible underlying developmental defect has not been investigated. OBJECTIVE: To report a case of multiple ILVEN-like lesions in a cat with a genetic variant in the NSDHL gene. ANIMALS: A 2-year-old, female, domestic short hair cat with a history of multiple alopecic, verrucous, hyperpigmented and erythematous skin lesions, following Blaschko's lines on the head, the limbs, the trunk and paw pads. METHODS AND RESULTS: According to the clinical and histopathological findings, a diagnosis of multiple ILVEN-like lesions was made. Genetic investigation revealed a heterozygous missense variant in the X-chromosomal NSDHL gene predicted to lead to a loss-of-function of the NSDHL protein. CONCLUSIONS AND CLINICAL IMPORTANCE: To the best of the authors' knowledge, this is the first case of feline ILVEN-like lesions in which a genetic cause has been proposed. Future studies to establish a causal relationship between NSDHL variants and skin lesions might lead to pathogenesis-directed treatments.

Topical polyhydroxy acid treatment for autosomal recessive congenital ichthyosis in the golden retriever: a prospective pilot study.

BACKGROUND: Autosomal recessive congenital ichthyosis (ARCI) in golden retrievers is due to a PNPLA1 gene mutation, which plays a role in epidermal lipid organization and metabolism. Topical therapies are used to reduce scaling; however, there are few published efficacy studies. OBJECTIVES: To examine the efficacy of topical treatment based on gluconolactone, a polyhydroxy acid with known beneficial effects on stratum corneum structure. ANIMALS: Sixteen golden retriever dogs with clinical signs of ARCI and PCR-confirmed PNPLA1 gene mutation. METHODS: This was a prospective, multicentre, noncontrolled study. Dogs were treated with a shampoo and lotion containing gluconolactone and other hydroxyl acids. Treatments were administered initially twice weekly for two weeks, then once weekly for two weeks and finally once monthly. Examinations were performed prior to and at 14 and 30 days of treatment to assess scaling, presence of other skin lesions and pruritus. In two dogs, pre- and 30 day post-treatment, skin biopsies were obtained. RESULTS: The extent and size of the scales were reduced by 60% and 75% after 14 and 30 days of treatment, respectively (P < 0.001). In 20% of the dogs, scaling was no longer observed after the first 30 days of treatment. No other skin lesions or pruritus were observed in any dog. Post-treatment biopsies showed normalization of the stratum corneum morphology and reduced hyperpigmentation. CONCLUSION AND CLINICAL IMPORTANCE: The frequent use of a shampoo and lotion containing gluconolactone may be an effective measure to improve skin scaling in golden retrievers with ARCI.

A retrospective study comparing histopathological and immunopathological features of nasal planum dermatitis in 20 dogs with discoid lupus erythematosus or leishmaniosis.

BACKGROUND: In areas endemic for leishmaniosis, discoid lupus erythematosus (DLE) and canine leishmaniosis (CanL) are the most common differential diagnoses for nasal planum erosive-ulcerative dermatitis in dogs. HYPOTHESIS/OBJECTIVE: To compare histopathological and immunopathological features of canine nasal planum erosive-ulcerative dermatitis with depigmentation due to DLE or CanL. ANIMALS: Nasal planum biopsies from dogs with nasal planum loss of architecture, depigmentation, swelling, erosions or ulcerations due to DLE (n = 14) or CanL (n = 6). METHODS: Sections of paraffin-embedded samples, stained with haematoxylin and eosin were reviewed. Samples were examined using antibodies targeting T cells (CD3), B cells (CD20), macrophages (Mac387) and class II major histocompatibility complex (MHC II). Histopathological and immunophenotypical findings were compared between DLE and CanL cases. RESULTS: Lichenoid and interface dermatitis were observed in both DLE and CanL cases. A nodular-to-diffuse, superficial and/or deep dermatitis with macrophages, lymphocytes and plasma cells was present only in CanL samples. CD20-positive cells predominated over CD3- and Mac387-positive cells in the two conditions. The percentage of dermal Mac387-positive cells was higher in CanL compared to DLE samples and the difference was statistically significant (P = 0.025). CONCLUSIONS/CLINICAL IMPORTANCE: In this study, similar histopathological and immunopathological findings were observed in dogs with nasal planum lesions due to DLE or CanL. Therefore, in areas endemic for leishmaniosis, the presence of the parasite should be investigated in canine nasal planum dermatitis showing clinical and histopathological features suggestive of DLE.

Rifampicin treatment of canine pyoderma due to multidrug-resistant meticillin-resistant staphylococci: a retrospective study of 32 cases.

BACKGROUND: Rifampicin has received increased interest in veterinary dermatology because of its activity against multidrug-resistant meticillin-resistant staphylococci (MRS). There is limited knowledge about the efficacy and safety of rifampicin in dogs. HYPOTHESIS/OBJECTIVE: To provide information on response to treatment and adverse effects in dogs treated with rifampicin for multidrug-resistant MRS pyoderma. ANIMALS: Thirty two dogs treated with rifampicin for rifampicin-susceptible multidrug-resistant MRS pyoderma. METHODS: Retrospective review of medical records, including alanine aminotransferase (ALT) and alkaline phosphatase (ALP) serum activity levels and total bilirubin concentrations, obtained before and throughout the treatment, was performed. RESULTS: Oral rifampicin as sole systemic antimicrobial therapy (median dose 5 mg/kg twice daily) was effective in 71.88% of cases. Topical antimicrobials were used in most cases. Median duration of rifampicin treatment was five weeks for superficial pyoderma and four weeks for deep pyoderma. Gastrointestinal signs were reported in 15% of treated dogs. Statistically significant increases of ALT (P = 0.045) and ALP (P = 0.0002) values after 3-4 weeks of treatment was observed. The median increase was equal to 0.3 and ×1.5 the upper limit of the reference ranges for ALT and ALP, respectively. CONCLUSIONS/CLINICAL IMPORTANCE: Oral rifampicin combined with topical antimicrobials can be considered an effective therapeutic option for canine superficial and deep pyoderma caused by rifampicin-susceptible multidrug-resistant MRS. Liver enzyme induction might be the most important cause of ALT and ALP increase associated with rifampicin therapy in dogs.

Effectiveness of a combined (4% chlorhexidine digluconate shampoo and solution) protocol in MRS and non-MRS canine superficial pyoderma: a randomized, blinded, antibiotic-controlled study.

BACKGROUND: There is a lack of studies comparing topical antiseptics to systemic antibiotics in the treatment of canine superficial pyoderma. HYPOTHESIS/OBJECTIVES: To compare the efficacy of topical chlorhexidine with systemic amoxicillin-clavulanic acid for the treatment of canine superficial pyoderma. ANIMALS: A randomized controlled trial was conducted in dogs with superficial pyoderma. Group T (n = 31) was treated topically with 4% chlorhexidine digluconate shampoo (twice weekly) and solution (once daily) for 4 weeks. Group S (n = 20) was treated orally with amoxicillin-clavulanic acid (25 mg/kg) twice daily for 4 weeks. METHODS: Bacterial culture and susceptibility testing were performed on clinical specimens collected before treatment. Severity of lesions and number of intracellular bacteria were evaluated using four-point scales to calculate a total pyoderma score for each dog. Pruritus was assessed by owners using a visual analog scale (range 0-10). Scores were analysed for statistical differences between groups T and S. RESULTS: Staphylococcus pseudintermedius was isolated from 48 dogs, including eight meticillin-resistant strains (MRSP). Although the number of dogs was small, no significant differences in pyoderma and pruritus scores were observed between groups throughout the study except for day 1, when group S had a significantly higher total score than group T (P = 0.03). Treatment with chlorhexidine products resulted in resolution of clinical signs in all dogs including those infected with MRSP. CONCLUSION AND CLINICAL IMPORTANCE: Topical therapy with chlorhexidine digluconate products may be as effective as systemic therapy with amoxicillin-clavulanic acid. This finding supports the current recommendations to use topical antiseptics alone for the management of superficial pyoderma.

Prevalence of Demodex canis-positive healthy dogs at trichoscopic examination.

Demodex canis is thought to be present in small numbers in the skin of most healthy dogs; however, available data on the prevalence of normal dogs harbouring D. canis are scarce. The purpose of this study was to investigate, using microscopic examination of plucked hairs, the prevalence of healthy dogs harbouring D. canis. Seventy-eight clinically healthy dogs with no history of dermatological problems and clinically normal skin and hair coat were included in the study. Five areas (perioral skin 2-3mm from both labial commissures, periungual skin of the third digit of both anterior paws and chin) were examined in each dog. Fifty to sixty hairs were plucked from each skin site and microscopically examined. No D. canis mites were observed and only one adult form of Demodex injai was found in the labial commissure of one dog. Based on these results, the estimated prevalence of healthy dogs harbouring D. canis in clinically normal skin should not exceed the threshold of 5.4%, with 95% confidence level. Considering our and previous findings, we propose that, although small numbers of D. canis might inhabit the skin of normal dogs, the probability of finding these mites in normal dogs is low. Consequently, in most cases, the presence of a D. canis mite in the skin should not be considered as indicative of normality.

Azole resistance of Malassezia pachydermatis causing treatment failure in a dog.

A 5-year-old neutered female toy Poodle chronically treated with systemic and topical azoles to control recurrent Malassezia dermatitis/otitis was presented because of the loss of treatment efficacy. Minimum Inhibitory Concentrations (MICs) obtained in vitro for various azoles (especially itraconazole and ketoconazole) against Malassezia strains isolated from the dog were increased by several-fold compared with MICs obtained for control isolates. These results reinforced the assumption based on clinical observation, i.e. the development of azole resistance.

A Large Deletion in the NSDHL Gene in Labrador Retrievers with a Congenital Cornification Disorder.

In heterozygous females affected by an X-linked skin disorder, lesions often appear in a characteristic pattern, the so-called Blaschko's lines. We investigated a female Labrador Retriever and her crossbred daughter, which both showed similar clinical lesions that followed Blaschko's lines. The two male littermates of the affected daughter had died at birth, suggesting a monogenic X-chromosomal semidominant mode of inheritance. Whole genome sequencing of the affected daughter, and subsequent automated variant filtering with respect to 188 nonaffected control dogs of different breeds, revealed 332 hetero-zygous variants on the X-chromosome private to the affected dog. None of these variants was protein-changing. By visual inspection of candidate genes located on the X-chromosome, we identified a large deletion in the NSDHL gene, encoding NAD(P) dependent steroid dehydrogenase-like, a 3ß-hydroxysteroid dehydrogenase involved in cholesterol biosynthesis. The deletion spanned >14 kb, and included the last three exons of the NSDHL gene. By PCR and fragment length analysis, we confirmed the presence of the variant in both affected dogs, and its absence in 50 control Labrador Retrievers. Variants in the NSDHL gene cause CHILD syndrome in humans, and the bare patches (Bpa) and striated (Str) phenotypes in mice. Taken together, our genetic data and the known role of NSDHL in X-linked skin disorders strongly suggest that the identified structural variant in the NSDHL gene is causative for the phenotype in the two affected dogs.