Hepatozoonosis in Free-Ranging American Mink (Neovison vison) in Pennsylvania, USA: Case Series

Hepatozoon spp. are protozoal organisms that infect a wide variety of animal hosts. Three free-ranging American mink (Neovison vison) from Pennsylvania, USA, were diagnosed with hepatozoonosis either as the primary cause of mortality or as a co-morbidity with canine distemper virus infection or trauma. In all cases, protozoa were detected in the lungs and/or heart with varying severity, as characteristic microgranulomas with intrahistiocytic merozoites as well as fewer distinct meronts. Partial 18S rRNA gene sequence from one case was identical to a Hepatozoon sp. previously detected in mink followed by a Hepatozoon sp. detected in ticks and other mustelid species. This paper expands on the limited knowledge of Hepatozoon spp. infecting North American mustelids and correlates that a previously detected Hepatozoon sp. in mink can cause histopathologic lesions and occasional mortality.