First confirmed canine case of Ehrlichia canis infection in Japan

An 11-year-old castrated Pekinese dog that had been moved from Indonesia to Japan eight years previously was diagnosed with an Ehrlichia canis infecti on by haematological characteristics (normocytic anaemia, mild thrombocytop enia and hypergammaglobulinaemia) and serological findings (antibody titre to E canis 1:3200 or more). The dog did not respond to treatment with tetra cycline and died from renal failure. The diagnosis was confirmed postmortem by pathological evaluation and polymerase chain reaction (PCR) followed by sequencing of the 16S rRNA gene. Typical morulae of Ehrlichia were detecte d in the cytoplasm of macrophages in spleen tissue by immunohistological st aining. Ehrlichia-like organisms were also detected in the spleen by electr on microscopy. E canis-specific PCR analysis of DNA extracted from the sple en gave a positive signal, and sequence analysis of the fragment revealed t hat it was identical to part of the 16S rRNA gene of E canis. The dog was t he first confirmed clinical case of E canis infection in Japan.