The taxonomic status of the brown dog tick (Rhipicephalus sanguineus sensu stricto), which has long been regarded as the most widespread tick worldwide and a vector of many pathogens to dogs and humans, is currently under dispute. We conducted a comprehensive morphological and genetic study of 278 representative specimens, which belonged to different species (i.e., Rhipicephalus bursa, R. guilhoni, R. microplus, R. muhsamae, R. pusillus, R. sanguineus sensu lato, and R. turanicus) collected from Europe, Asia, Americas, and Oceania. After detailed morphological examination, ticks were molecularly processed for the analysis of partial mitochondrial (16S rDNA, 12S rDNA, and cox 1) gene sequences. In addition to R. sanguineus s.l. and R. turanicus, three different operational taxonomic units (namely, R. sp. I, R. sp. II, and R. sp. III) were found on dogs. These operational taxonomical units were morphologically and genetically different from R. sanguineus s.l. and R. turanicus. Ticks identified as R. sanguineus s.l., which corresponds to the so-called “tropical species” (=northern lineage), were found in all continents and genetically it represents a sister group of R. guilhoni. R. turanicus was found on a wide range of hosts in Italy and also on dogs in Greece. The tropical species and the temperate species (=southern lineage) are paraphyletic groups. The occurrence of R. turanicus in the Mediterranean region is confirmed. A consensual re-description of R. sanguineus s.s. and R. turanicus will be necessary to solve the taxonomic problems within the so-called R. sanguineus group.

Thirty-nine parvovirus strains contained in faecal samples collected in Italy (n=34) and UK (n=5) from cats with feline panleukopenia were characterized at the molecular level. All viruses were proven to be true feline panleukopenia virus (FPLV) strains by a minor groove binder probe assay, which is able to discriminate between FPLV and the closely related canine parvovirus type 2. By using sequence analysis of the VP2 gene, it was found that the FPLV strains detected in Italy and UK were highly related to each other, with a nucleotide identity of 99.1–100 and 99.4–99.8 % among Italian and British strains, respectively, whereas the similarities between all the sequences analysed were 98.6–100 %. Eighty-eight variable positions were detected in the VP2 gene of the field and reference FPLV strains, most of which were singletons. Synonymous substitutions (n=57) predominated over non-synonymous substitutions (n=31), and the ratio between synonymous and non-synonymous substitutions (dN/dS) was 0.10, thus confirming that evolution of FPLV is driven by random genetic drift rather than by positive selection pressure. Some amino acid mutations in the VP2 protein affected sites that are thought to be responsible for antigenic and biological properties of the virus, but no clear patterns of segregation and genetic markers, were identified, confirming that FPLV is in evolutionary stasis.