Description of the Nematode Dirofilaria repens (Nematoda, Onchocercidae) Parasitic in Dogs in Ukraine

Dirofilariasis is a zoonotic disease of domestic and wild carnivores and humans. Subcutaneous migration of the parasite Dirofilaria repens Railliet & Henry, 1911 may cause local swelling with variable localisation. In humans, this parasite can cause damage to the lungs, male genitalia and eyes. The range of D. repens is constantly expanding into new areas and, considering the zoonotic potential of this parasite, it is important to extend the existing data on the morphology of D. repens. The present study provides a morphometric description of D. repens nematodes obtained from subcutaneous tissues of dogs in Ukraine. The aim of this study was to highlight the key features for the identification of parasites of this species. For males, 27 morphometric characteristics were identified, characterising the overall size of the body and the oesophagus, the thickness of the cuticle in the region of the mouth opening, the localisation of the nerve ring and the cloaca, the morphological structure and metric parameters of the spicules, and the length of the tail. For females, 18 morphometric traits were identified that, in addition to common parameters, characterize cuticle thickness in the region of the vulva, localisation of the vulva and anus, body width in the regions of the anus and vulva, and tail length. This report adds to the existing data on the morphological and metric characteristics of D. repens nematodes.