Ectoparasites as viral vectors in veterinary medicine: prevalence in companion animals

Ectoparasites in companion animals are not only a clinical problem, but also a major epidemiological factor, being vectors for the transmission of pathogens, including some viruses of zoonotic importance. In particular, Rhipicephalus sanguineus, the brown dog tick, is recognized as a vector involved in the transmission of Crimean–Congo hemorrhagic fever virus (Nairoviridae) and some viruses of the Flaviviridae family. This species thus acquires particular relevance for veterinary medicine and public health, in the light of the One Health concept. The present study evaluated 100 clinical cases of dogs, cats and other companion animals presented to the Medicrisvet clinic (Fălticeni, Romania) in 2024, with the objective of determining the prevalence of ectoparasites and analyzing the associated risks. The results showed a prevalence of 54.8% for R. sanguineus, 26.9% for Demodex cati, 11.5% for Otodectes cynotis and 6.7% for Sarcoptes scabiei var. canis. Infestations were more frequent in the warm season, indicating a period of increased vulnerability for the transmission of pathogens, including viral ones. These results highlight the importance of ectoparasites as vectors with viral relevance in veterinary medicine and public health. The high prevalence of Rhipicephalus sanguineus in companion animals suggests a major epidemiological potential, with direct implications for zoonotic risk and the emergence of viral agents. The integration of these data in the current context of veterinary virology supports the strengthening of surveillance and control programs and emphasizes the need to develop health policies based on the One Health concept. Therefore, this study contributes to the understanding of the role of ectoparasites in viral ecology and to the substantiation of interdisciplinary preventive strategies, from risk assessment to limiting the transmission of pathogens.