One of the most common ectoparasites on domestic carnivores are fleas from the genus Ctenocephalides. This group of blood sucking insects are one of the most important in medical and veterinary terms, as they can serve as carriers of dangerous infectious and may cause other invasive diseases. Research studies have established a variety of fleas and other contagions parasitizing domestic dogs in Poltava, Ukraine. Certain peculiarities of these ectoparasitic studies, as a part of mixed infestations of dogs, have recently been determined. The results of the studies have shown that the species composition of the fleas was represented by two main species. The dominant species was Ct. felis, and their prevalence was 36.05 %. Another species (Ct. canis) was diagnosed less often and had a prevalence of 27.94 %. It was found that in 31.18 % of the dogs, the blood-sucking insects were mostly parasitizing in the form of an associations with: nematoda (Toxocara canis, Trichuris vulpis, Uncinaria stenocephala), Cestoda (Dipylidium caninum), protozoa (Cystoisospora canis), and another ectoparasite (Trichodectes canis). Overall, 33 types of mixed infestations were detected. Moreover, the number of different parasitic species in each dog ranged from one to seven. Fleas of the genus Ctenocephalides (in the composition of two species of parasites) were registered the most often (14.60 %). The infestation of dogs with other forms of mixed infestations was 0.69—8.01 %. The most frequent co-members for Ct. felis were Cestoda [D. caninum (13.47 %)], for Ct. canis—Cestoda [D. caninum (11.23 %)] and Nematoda [T. vulpis (8.29 %)].
