Cutaneous Alternaria infectoria infection in a dog in association with therapeutic immunosuppression for the management of immune‐mediated haemolytic anaemia

A 4‐year‐old, ovariohysterectomized, English springer spaniel on immunosuppressive therapy was re‐examined for the review of its immune‐mediated haemolytic anaemia and the recent development of skin lesions. For the 3 months since hospital discharge, the dog had been receiving 1.3 mg/kg prednisolone and 2.6 mg/kg ciclosporin, both administered orally twice daily. Physical examination revealed hepatomegaly and multiple, purulent, crusting, erosive to ulcerative lesions over different body areas. Onychorrhexis had occurred on one digit and the underlying corium had blackened. There were two proliferative and one plaque‐like lesions in the mouth. Thick walled fungal hyphae were detected in impression smears from all skin lesions and staining with periodic acid–Schiff’s stain confirmed the presence of multiple fungal hyphae and spores in all biopsies examined. Fungal culture isolated a heavy, pure growth of an Alternaria sp. which was identified as A. infectoria by sequencing the internal transcribed spacer 1 region of the rRNA gene. The animal’s condition prevented detailed investigation of the oral lesions. Withdrawal of the ciclosporin and reduction of the prednisolone dosage resulted in spontaneous resolution of the skin lesions within 40 days. Further gradual decrements in the prednisolone dosage to zero were carried out without recurrence of the immune‐mediated haemolytic anaemia. After 12 months, there has been no recurrence of either the skin lesions or the anaemia. To the authors’ knowledge, this is the first reported case of A. infectoria infection in a dog. Résumé Une Springer spaniel anglais de 4 ans, ovariohystérectomisée, sous thérapie immunosuppressive, a été ré‐examinée pour le suivi de ses anémies hémolytiques à médiation immune et le développement récent de lésions cutanées. Au cours des 3 mois depuis sa sortie de l’hôpital, l’animal a reçu 1.3 mg/kg de prednisolone et 2.6 mg/kg de ciclosporine par voie orale toutes les 12 heures. L’examen général a révélé une hépatomégalie et de multiples lésions purulentes, crouteuses, érosives à ulcératives sur différentes régions du corps. Un doigt était atteint d’ onychorrhexis et la peau sous‐jacente avait noircie. Il y avait deux lésions prolifératives et une lésion en plaque dans la gueule. Des hyphes fongiques à paroi épaisse ont été mis en évidence par calque direct de toutes les lésions cutanées et une coloration à l’acide périodique de Schiff a confirmé la présence de multiples hyphes et spores fo