Concomitant Cutaneous Neosporosis and Toxoplasmosis in a Golden Retriever

Introduction: This report describes a case of concomitant cutaneous neosporosis (CN) and cutaneous toxoplasmosis (CT) in a dog. Materials and Methods: A 10-year-old, female golden retriever be- ing treated with ciclosporin for an autoimmune disorder suddenly developed multifocal cutaneous nodules. Imprints, fine needle aspi- rates and skin punch biopsy samples were submitted. An immunoflu- orescence antibody test (IFAT) on serum samples was performed twice at a 1-month interval. Unstained smears and dewaxed sections of skin were immunochemically labelled with polyclonal anti-Toxo- plasma gondii (TG) and anti-Neospora caninum (NC) primary anti- bodies. PCR assay with primers for TG and NC were conducted using DNA extracted from cutaneous formalin-fixed and paraffin wax-embedded tissue. Results: Cytology demonstrated degenerate neutrophils admixed with fewer reactive macrophages containing numerous intracytoplasmic crescent shaped, 4e6 mm microorganisms, with a light basophilic cyto- plasm and a central nucleous (tachyzoites). Histology revealed diffuse and severe neutrophilic, histiocytic and eosinophilic dermatitis and panniculitis associated with necrotizing vasculitis. Elevated numbers of free and cytoplasmic tachyzoites within macrophages and epidermal and follicular keratinocytes were present. IFAT was positive for both TG and NC, with increased TG antibody titres after 1 month. Immu- nochemistry and PCR confirmed a concomitant TG and NC cutaneous infection. Clindamycin (11 mg/kg PO q12 h) and withdrawal of immu- nosuppressive medication resulted in clinical remission. Conclusions: CN and CT are rare manifestation of both diseases. To the best of our knowledge this is the first report of a simultaneous infection of TG and NC with a cutaneous anatomical location.