J Vet Diagn Invest 13:17–21 (2001) An indirect enzyme-linked immunosorbent assay for diagnosis of American canine hepatozoonosis

Abstract. American canine hepatozoonosis (ACH), caused by Hepatozoon americanum, is an emerging tick-borne disease of dogs. An indirect enzyme-linked immunosorbent assay (ELISA) that should facilitate diagnosis of infection and study of the epidemiology of ACH has been developed using H. americanum spo-rozoites as antigen. Efficacy of the new test as a diagnostic tool was compared with that of skeletal muscle biopsy, the current gold standard for confirming H. americanum infection. Results show that the test is sensitive (93%) and specific (96%) and that it is as reliable as histopathologic examination of skeletal muscle for detecting infection. The ELISA would be suitable as a routine laboratory test for diagnosis of ACH. Canine hepatozoonosis was first described in India, with the causative organism classified as Leukocyto-zoon canis.7 Later, the genus Hepatozoon was de-scribed,14 and the dog parasite was subsequently trans-ferred to this genus.20 American canine hepatozoonosis (ACH) is an emerging tick-borne disease of dogs in the USA;9 the New World parasite was described as a new species, H. americanum, based on the location o