Putative pemphigus-like reaction to oral fluralaner in a dog.

A 9-month-old mixed-breed dog developed generalised pustular dermatitis, accompanied by lethargy and hyperthermia, 7 days after oral fluralaner administration. Dermatopathological and microbiological evaluations were consistent with a pustular acantholytic dermatitis. A 4-month course of immunosuppressive therapy resulted in complete remission of lesions, which did not recur after therapy was withdrawn.

Un chien croisé âgé de 9 mois a développé une dermatite pustuleuse généralisée, accompagnée de léthargie et d'hyperthermie, 7 jours après l'administration orale de fluralaner. Les évaluations dermatopathologiques et microbiologiques sont compatibles avec une dermatite acantholytique pustuleuse. Un traitement immunosuppresseur de 4 mois induit une rémission complète des lésions, qui n'ont pas récidivé après l'arrêt du traitement.

Um cão mestiço de nove meses de idade desenvolveu uma dermatite pustular generalizada, acompanhada de letargia e hipertermia, 7 dias após administração de fluralaner. As avaliações dermatohistopatológicas e microbiológicas foram consistentes com uma dermatite pustular acantolítica. Um curso de quatro meses com terapia imunossupressiva resultou em remissão completa das lesões, que não recidivaram após o fim do tratamento.

Un perro mestizo de 9 meses desarrolló dermatitis pustulosa generalizada, acompañada de letargo e hipertermia, 7 días después de la administración oral de fluralaner. Las evaluaciones dermatopatológicas y microbiológicas fueron compatibles con una dermatitis pustulosa acantolítica. Un tratamiento inmunosupresor de 4 meses dio como resultado la remisión completa de las lesiones, que no reaparecieron después de retirar el tratamiento.

Effect of Local Administration of Meglumine Antimoniate and Polyhexamethylene Biguanide Alone or in Combination with a Toll-like Receptor 4 Agonist for the Treatment of Papular Dermatitis due to Leishmania infantum in Dogs.

Papular dermatitis is a cutaneous manifestation of canine Leishmania infantum infection associated with mild disease. Although it is a typical presentation, nowadays, there is still no established treatment. This study evaluated the safety and clinical efficacy of local meglumine antimoniate, locally administered polyhexamethylene biguanide (PHMB) alone or PHMB in combination with a Toll-like receptor 4 agonist (TLR4a) for the treatment of papular dermatitis due to L. infantum and assessed parasitological and immunological markers in this disease. Twenty-eight dogs with papular dermatitis were divided randomly into four different groups; three of them were considered treatment groups: PHMB (n = 5), PHMB + TLR4a (n = 4), and meglumine antimoniate (n = 10)), and the remaining were considered the placebo group (n = 9), which was further subdivided into two sub-groups: diluent (n = 5) and TLR4a (n = 4). Dogs were treated locally every 12 h for four weeks. Compared to placebo, local administration of PHMB (alone or with TLR4a) showed a higher tendency towards resolution of papular dermatitis due to L. infantum infection at day 15 (χ2 = 5.78; df = 2, p = 0.06) and day 30 (χ2 = 4.; df = 2, p = 0.12), while local meglumine antimoniate administration demonstrated the fastest clinical resolution after 15 (χ2 = 12.58; df = 2, p = 0.002) and 30 days post-treatment (χ2 = 9.47; df = 2, p = 0.009). Meglumine antimoniate showed a higher tendency towards resolution at day 30 when compared with PHMB (alone or with TLR4a) (χ2 = 4.74; df = 2, p = 0.09). In conclusion, the local administration of meglumine antimoniate appears to be safe and clinically efficient for the treatment of canine papular dermatitis due to L. infantum infection.

Histological and parasitological distinctive findings in clinically-lesioned and normal-looking skin of dogs with different clinical stages of leishmaniosis.

BACKGROUND: Normal-looking skin of dogs with leishmaniosis frequently shows microscopic lesions along with the presence of Leishmania amastigotes. However, histological lesions with or without detection of amastigotes might not occur in less severe clinical cases. In addition, comparative studies between paired clinically-lesioned and normal-looking skin samples from dogs with different disease severity are lacking. The objective of this study was to compare histological and parasitological findings by Leishmania immunohistochemistry (IHC) and quantitative PCR (qPCR) on paired clinically-lesioned and normal-looking skin biopsies from 25 dogs with different clinical stages of leishmaniosis, 11 with stage I-mild disease (papular dermatitis) and 14 with stage II-III (ulcerative or exfoliative dermatitis). RESULTS: The study demonstrated microscopic lesions in 14 out of 25 (56%) samples from normal-looking skin biopsies. In those samples, perivascular to interstitial dermatitis composed by macrophages with lymphocytes and plasma cells was observed mainly in the superficial and mid-dermis. The intensity of the dermatitis was mild to moderate and always less prominent than in the clinically-lesioned skin. In normal-looking skin samples, the presence of parasites was detected by histology, IHC and qPCR in 5/25 (20%), 8/25 (32%) and 18/25 (72%), respectively. Leishmania was encountered in 11/25 (44%), 23/25 (92%) and 25/25 (100%) of clinically-lesioned skin samples by histology, IHC and qPCR, respectively. Normal-looking skin from dogs with stage I-mild disease was less frequently inflamed (P = 0.0172). Furthermore, Leishmania was more easily demonstrated by histology (P = 0.0464), IHC (P = 0.0421) or qPCR (P = 0.0068) in normal-looking skin of dogs with stage II-III-moderate to severe disease. In addition, in the latter group, there was a significantly higher parasite load studied by means of qPCR than in dogs with less severe disease (P = 0.043). Clinically-lesioned skin from dogs with stage I disease was more frequently characterised by the nodular to diffuse pattern and granuloma formation (P = 0.0166) and by a lower parasite load studied by means of qPCR (P = 0.043) compared with more diseased dogs. CONCLUSIONS: Normal-looking skin from dogs with stage I is less likely to present histological lesions as well as harbour the parasite when compared with dogs with moderate to severe leishmaniosis.

Efficacy of a new topical cyclosporine A formulation in the treatment of atopic dermatitis in dogs.

Topical treatment with cyclosporine A (CsA) has recently become possible with the development of novel nanotechnology pharmaceutical formulations of CsA able to penetrate through the epidermis providing good absorption and dermal action. The aim of this multicentre, blinded, parallel, randomized, placebo controlled trial was to evaluate the efficacy of a new topical CsA formulation in dogs with atopic dermatitis (AD). Dogs (n=32) with severe and moderate clinical signs of non-seasonal AD, but few localized lesions, were randomly allocated to receive topical CsA (17 dogs) or placebo (15 dogs) and were treated twice a day for 6 weeks. Before and 21 and 45 days after starting the treatment, the severity of a previously selected skin lesion was evaluated according to a dermatological scoring system. Owners using a visual analogue scale also assessed pruritus weekly and effectiveness of the treatment was defined as a reduction of at least 50% in these variables after 45 days. After 21 and 45 days the lesion severity score in animals treated with CsA was significantly lower than at baseline (P<0.01, both times). In contrast, the animals on placebo showed no significant improvement at days 21 or 45. The percentage of dogs with an effective reduction in pruritus at the end of the trial was 87.5% and 28.6% in the CsA and placebo groups, respectively. These results suggest that topical administration of CsA is effective in reducing the severity of skin lesions and pruritus in dogs with moderate to severe AD as soon as 3 weeks after starting treatment.