Without any doubts, host attractiveness plays a key role in the determination of the population at risk of exposure. Indeed, mosquito host preferences have been well documented, both at species and at individual level [28]. Accordingly, in the present investigation, Cx pipiens fed preferentially on dogs (70%) than on humans (26%), and was differently attracted by the three dogs used in the study, independently from their sizes. Besides the individual host attractiveness to mosquitoes, the microfilaraemic status of the dogs may enhance the host-preference of Cx pipiens. Accordingly, Cx pipiens displayed a higher feeding rate on a microfilaraemic dog, compared to a dog under preventative treatment (i.e., 47% vs 6.7-12.9%) [13]. Similarly, the mosquito host attractiveness is also enhanced in human patients infected by Plasmodium spp. [29,30] indicating that alterations of the physiological status (disease conditions) and consequently of physiological parameters, may ultimately change the animal cue attractants (fever, sweat and breathing rhythm and odour) to competent vectors. Although these factors might have an impact on the spread of the infection, they remain purely speculative for dirofilarioses.