Abstract:
This is the first comprehensive review of the literature pertaining to Babesia species
reported from domestic cats. Description of the four species (Babesia felis, Babesia
cati, Babesia herpailuri, and Babesia pantherae) named based on morphology and/or
host specificity is documented. Feline babesiosis is of major veterinary concern only in
South Africa. Reports of the rare occurrence of feline babesiosis cases in Europe (France,
Germany, Poland, and Spain) and Asia (Israel, India, and Pakistan) are documented.
Molecular characterization has revealed that cats can harbor a variety of Babesia species.
The previous practice of referring to all piroplasms, especially small ones, seen on
feline blood smears as B. felis is therefore no longer tenable. The near-full-length 18S
rRNA gene sequences entered into GenBank in 2001 (accession no. AF244912) are
designated as definitive for B. felis sensu stricto. All published literature relating to
molecular characterization of feline Babesia species that could be traced was critically
assessed. Four Babesia species are now known to be involved in causing feline
babesiosis in South Africa: the closely related B. felis s.s. and Babesia leo (clade I),
Babesia lengau (clade II), and Babesia species cat Western Cape (clade VI, Babesia
s.s.). Clade VI also includes Babesia canis presentii and Babesia hongkongensis reported
from cats in Asia. Six other Babesia species have been reported from domestic cats: the
dog-associated B. canis s.s., Babesia gibsoni, and B. vogeli, as well as Babesia lohae,
Babesia microti, and Babesia vulpes. Phylogenetic relationships of all named species
were assessed and are presented as trees. The relatively high prevalence of B. vogeli in
clinically healthy cats (16%in Brazil, 13%on St Kitts, and 8.1%in Portugal) suggests that
immunocompetent cats can harbor the infection with no discernible untoward effects.
Reports of occurrence of B. felis and other Babesia species in domestic cats should be
accepted only if they are supported by credible molecular provenance.