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. 2025 Jul 5;21(1):438.
doi: 10.1186/s12917-025-04867-w.

Molecular investigation of Dirofilaria repens, Dirofilaria immitis and Acanthocheilonema reconditum in stray dogs and cats in Ukraine

Mateusz Pękacz #  1 , Kateryna Slivinska #  2   3 , Alla Vyniarska  4 , Katarzyna Basałaj  2 , Alicja Kalinowska  2 , Agnieszka Wesołowska  2 , Alicja Laskowska  1 , Olesia Kysterna  5 , Andrii Klietsov  5   6 , Martina Miterpáková  7 , Andrei Daniel Mihalca  8 , Jakub Gawor  9 , Vitaliy Kharchenko  3 , Anna Zawistowska-Deniziak  10   11
Affiliations

Molecular investigation of Dirofilaria repens, Dirofilaria immitis and Acanthocheilonema reconditum in stray dogs and cats in Ukraine

Mateusz Pękacz et al. BMC Vet Res. .

Abstract

Background: The increasing population of stray dogs and cats in Ukraine poses an important risk of the transmission of vector-borne parasites, particularly Dirofilariarepens, Dirofilaria immitis and Acanthocheilonema reconditum, all of which are zoonotic and may affect human health. Despite numerous reports of human dirofilariosis in Ukraine, epidemiological data on these filarial parasites in companion animals remain limited. The aim of the study was to conduct a molecular epidemiological survey to assess the prevalence of filarial infections in stray dogs and cats across Ukraine and evaluate factors associated with infection in dogs. In collaboration with the European Scientific Counsel Companion Animal Parasites (ESCCAP) and local non-governmental organizations (NGOs), a total of 457 blood samples (233 dogs and 224 cats) were collected between March and December 2023 from Berdychiv, Lviv, Kharkiv, Sumy and Zvenyhorodka. Molecular detection of D. repens, D. immitis, and A. reconditum was performed using a two-step quantitative PCR (qPCR) assay with novel species-specific primers.

Results: The method demonstrated high sensitivity and specificity, capable of detecting DNA from a single microfilaria, with no evidence of cross-reactivity among target species. Among the canine samples, 66 (28.3%) tested positive for at least one filarial species, including cases of both mono- and co-infection. In contrast, only 8 feline samples (3.6%) were positive for D. repens or D. immitis. Statistical analysis revealed a higher prevalence among male dogs and those weighing over 10 kg, while the lowest prevalence was observed in the youngest age group (< 3 years).

Conclusions: These findings provide the first molecular evidence of Dirofilaria spp. and A. reconditum infections in stray animals from several under-studied areas of Ukraine, highlighting the relevance of the One Health approach in mitigating the risk of zoonotic transmission.

Keywords: Acanthocheilonema; Dirofilaria; Molecular epidemiology.

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Conflict of interest statement

Declarations. Ethics approval and consent to participate: This research was carried out in collaboration with ESCCAP and several Ukrainian NGOs, as part of a comprehensive national initiative targeting the sterilization and vaccination of stray animals, which also includes parasitological examinations. All analyses were performed on residual blood samples collected during routine checkups and diagnostic procedures. As per the Resolution on the Protection of Animals Used for Scientific or Educational Purposes (15 January 2015) [46], no ethical approval or license was required for this study. Due to the absence of formal owners, written informed consent was not obtained. However, caregivers of the animals and/or the directors of local shelters were informed about the results of Dirofilaria/Acanthocheilonema testing. Additionally, veterinarians were provided with comprehensive information to facilitate the implementation of appropriate treatment for infected dogs. The manuscript adheres to the recommendations in the ARRIVE guidelines [47]. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
The geographic distribution of filariae infections in Ukrainian stray dogs and cats. The administrative areas where the investigation was conducted were labeled in varying shades of red, reflecting the frequency of occurrence. The cities where the investigation was conducted were marked with pins of different colors: grey for Lviv, blue for Berdychiv, yellow for Zvenyhorodka, purple for Kharkiv, and green for Sumy. The capital city of Ukraine, Kyiv, was indicated by a house icon
Fig. 2
Fig. 2
Prevalence of Dirofilaria and Acanthocheilonema infections in dogs and cats. (A) Occurrence frequency of each species, including both mono- and co-infections, in dogs and cats compared to negative (uninfected) animals. (B) Detailed analysis of infection patterns among infected dogs and cats. DR - D. repens; DI - D. immitis; AR - A. reconditum
Fig. 3
Fig. 3
Infection patterns frequency in affected dogs across Berdychiv, Lviv, Kharkiv, Sumy and areas. DR - D. repens; DI - D. immitis; AR - A. reconditum
Fig. 4
Fig. 4
Comparative prevalence of filarial infections across dogs categorized by sex, age and weight. All dogs in the study were grouped according to their sex (male/female), weight (< 10 kg; 10–25 kg; ≥25 kg), and age (< 3 years; 3–10 years; ≥10 years)
Fig. 5
Fig. 5
Sensitivity evaluation of the Real-Time assay using pan-filarial primers targetingcox1. The assay was tested with gDNA from 1, 3, or 10 microfilariae (mf). Reactions were performed in triplicate across three biological replicates using blood from three different dogs
Fig. 6
Fig. 6
Melt curve analysis of the products amplified using gene-specific primers. Plots display melt curves corresponding to primers specific for Onchocercidae family (A), D. repens (B), D. immitis (C), and A. reconditum (D). Primers specificity was assessed with genomic DNA isolated from blood from dogs infected with D. repens (blue), D. immitis (red) and A. reconditum (purple), B. patei (black), O. lupi (grey). NTC (green) implies „no target control”
See this image and copyright information in PMC

References

    1. Otranto D, Cantacessi C, Dantas-Torres F, Brianti E, Pfeffer M, Genchi C, et al. The role of wild Canids and felids in spreading parasites to dogs and cats in europe. Part II: helminths and arthropods. Vet Parasitol. 2015;213:24–37. - PubMed
    1. Alsarraf M, Dwużnik-Szarek D, Hildebrand J, Mierzejewska EJ, Kloch A, Kot K, et al. Occurrence of dirofilaria repens in wild carnivores in Poland. Parasitol Res. 2023;122:1229–37. - PMC - PubMed
    1. Miterpáková M, Hurníková Z, Zaleśny G, Chovancová B. Molecular evidence for the presence of Dirofilaria repens in Beech Marten (Martes foina) from Slovakia. Vet Parasitol. 2013;196:544–6. - PubMed
    1. Ionică AM, Deak G, Boncea R, Gherman CM, Mihalca AD. The European Badger as a new host for Dirofilaria immitis and an update on the distribution of the heartworm in wild carnivores from Romania. Pathogens. 2022;11. - PMC - PubMed
    1. Capelli G, Genchi C, Baneth G, Bourdeau P, Brianti E, Cardoso L et al. Recent advances on Dirofilaria repens in dogs and humans in Europe. Parasit Vectors. 2018;11. - PMC - PubMed

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