Of growing concern globally is the indication that
these viruses have caused significant epizootics in a
variety of reptile and fish species (Chinchar et al.
2009, Gray et al. 2009b, Lesbarrères et al. 2012).
Whether amphibian, reptile, and fish populations
transfer these viruses among one another remains an
important unanswered question, but the possibility
broadens the concern for ranavirus risk assessment
and disease management. Another complication is
that ranavirus can be widespread in amphibian populations without causing any obviously associated
disease or mortalities (Miller et al. 2009, Uyehara et
al. 2010, Hoverman et al. 2012), and FV3 has been
considered minimally pathogenic (Majji et al. 2006).
Further, in the asymptomatic carrier form, host populations may also differ in their responses to infection
(Robert et al. 2011). Our histopathology findings for
FV3-infected southern leopard frogs were inconsistent with previous descriptions of FV3 (Gray et al.
2009b), in which the hematopoietic tissue has usually
been necrotic (Daszak et al. 1999, Greer et al. 2005)
and infections appeared to be subclinica